In Vitro Diagnostic (IVD) Devices: The Complete Regulatory Guide for FDA and EU IVDR

What Are In Vitro Diagnostic Devices?

In vitro diagnostic (IVD) devices are medical devices used to examine specimens derived from the human body — blood, urine, saliva, tissue, cerebrospinal fluid, swabs, and other biological samples — to provide information for diagnosing disease, monitoring health conditions, determining treatment eligibility, or screening populations. The term "in vitro" literally means "in glass," reflecting the fact that analysis happens outside the body, in a test tube, on a test strip, or inside an automated laboratory analyzer.

IVDs are everywhere. A home pregnancy test is an IVD. The blood glucose monitor a diabetic patient uses several times a day is an IVD. The PCR instrument that identifies SARS-CoV-2 RNA is an IVD. The next-generation sequencing panel that identifies actionable oncology mutations to guide targeted therapy is an IVD. The software algorithm that interprets digital pathology images to flag potential malignancies is an IVD. From the simplest lateral flow strip to the most complex multi-analyte molecular platform, IVDs share a common regulatory identity: they are medical devices, and they are regulated as such.

Approximately 70% of all clinical decisions are influenced by IVD results, according to the World Health Organization. More than 40,000 distinct IVD products are available globally. The global IVD market was valued at approximately USD 104 billion in 2025, with projections reaching USD 136 billion by 2035 — driven by the rising prevalence of chronic and infectious diseases, advances in molecular diagnostics and point-of-care testing, and the integration of artificial intelligence into diagnostic workflows.

Yet despite their ubiquity, IVDs occupy a regulatory space that is distinct from — and in many ways more complex than — traditional medical devices. Because IVDs do not directly contact or interact with the patient (in most cases), the nature of risk is fundamentally different. The danger of an IVD is not that it will burn, puncture, or mechanically fail inside the body. The danger is that it will give a wrong answer — a false positive that leads to unnecessary treatment, or a false negative that delays a life-saving diagnosis.

This guide covers the entire regulatory landscape for IVD devices: what they are, how they are classified, the FDA and EU IVDR frameworks in detail, performance evaluation, companion diagnostics, laboratory developed tests, point-of-care and self-testing requirements, AI/ML in diagnostics, quality management, post-market surveillance, and international regulatory requirements.

Whether you are an IVD startup developing your first diagnostic assay, a contract manufacturer producing reagents for multiple clients, a regulatory affairs professional preparing a 510(k) or IVDR conformity assessment, or a laboratory considering the implications of LDT regulation — this guide provides the comprehensive reference you need.

In Vitro vs. In Vivo Diagnostics

Understanding the distinction between in vitro and in vivo diagnostics is fundamental to navigating the regulatory landscape. Although both contribute to clinical decision-making, they operate on fundamentally different principles and are subject to different regulatory frameworks.

In vitro diagnostics analyze specimens that have been removed from the body. The test is performed in a controlled environment — a laboratory, a point-of-care setting, or even the patient's home — using reagents, instruments, or software to detect or measure analytes in the specimen. Examples include blood glucose monitoring, PCR testing for infectious agents, immunoassays for tumor markers, and NGS-based genomic profiling.

In vivo diagnostics measure physiological parameters directly on or within the living body. These include imaging modalities (X-ray, CT, MRI, PET, ultrasound), physiological monitoring devices (pulse oximeters, blood pressure monitors, ECG/EKG), and implantable sensors (continuous glucose monitors with subcutaneous sensors). In vivo diagnostics are regulated as general medical devices, not as IVDs.

The boundary between in vitro and in vivo can be nuanced. A continuous glucose monitor (CGM) that uses an implanted sensor to measure interstitial glucose is regulated as a general medical device (in vivo), even though it measures the same analyte — glucose — that a blood glucose meter (an IVD) measures. The distinguishing factor is not what is measured but where the measurement occurs: outside the body (in vitro) or inside/on the body (in vivo).

Characteristic	In Vitro Diagnostics	In Vivo Diagnostics
Where testing occurs	Outside the body (specimen-based)	On or inside the body
Specimen required?	Yes — blood, urine, saliva, tissue, swabs	No — measures directly on the patient
Examples	Blood glucose meters, pregnancy tests, PCR assays, NGS panels, immunoassays	X-ray, MRI, CT, ultrasound, pulse oximeters, ECG, CGMs
Regulatory classification	IVD-specific regulations (21 CFR 809, IVDR)	General medical device regulations (21 CFR 860-892, MDR)
Risk profile	Incorrect test results (false positives/negatives)	Physical harm from energy, implantation, or device-body interaction
Clinical role	Diagnosis, screening, monitoring, treatment selection	Imaging, physiological monitoring, real-time parameter measurement

In practice, in vitro and in vivo diagnostics are complementary. A patient with suspected cancer may undergo in vivo imaging (CT scan) to identify a tumor, followed by a tissue biopsy analyzed by in vitro diagnostics (IHC, NGS) to determine the molecular profile and guide targeted therapy selection.

Why IVDs Matter: The Clinical and Economic Impact

IVDs are often described as the backbone of modern medicine — and the data supports this claim. Despite accounting for only approximately 2-3% of total healthcare spending, IVDs influence an estimated 60-70% of all clinical decisions, according to multiple studies cited by the World Health Organization and the European Diagnostic Manufacturers Association (EDMA).

Clinical Impact

The clinical value of IVDs extends across the full continuum of care:

• Early disease detection: IVDs enable earlier diagnosis of diseases that are more treatable when caught early. For hepatocellular carcinoma (liver cancer), studies have shown that mortality rates decrease by approximately 37% when the disease is detected through advanced diagnostics rather than at symptomatic presentation. For cervical cancer, HPV-based IVD screening has been shown to reduce cervical cancer incidence by 60-70% compared to conventional cytology.
• Infectious disease control: IVDs serve as the first line of defense against the spread of infectious diseases. The COVID-19 pandemic demonstrated the critical role of rapid diagnostic testing in enabling quarantine protocols, contact tracing, and public health decision-making. Blood screening IVDs for HIV, HCV, and HBV have virtually eliminated transfusion-transmitted infections in countries with universal screening programs.
• Treatment optimization: Companion diagnostics and pharmacogenomic testing allow clinicians to select therapies with the highest probability of efficacy for individual patients, avoiding ineffective treatments and their associated side effects and costs. Studies have shown that biomarker-guided treatment selection in oncology improves response rates by 30-50% compared to empiric therapy.
• Chronic disease management: IVDs such as blood glucose monitors and HbA1c tests enable patients with diabetes to manage their condition effectively, reducing hospitalizations and long-term complications. Self-monitoring of INR with home coagulation devices has been shown to reduce thromboembolic events and major bleeding in patients on anticoagulation therapy.
• Antimicrobial stewardship: Rapid diagnostic IVDs that identify pathogens and their resistance profiles within hours (rather than days with traditional culture) enable targeted antibiotic therapy, reducing inappropriate antibiotic use and slowing the development of antimicrobial resistance — one of the most significant global public health threats.

Economic Impact

IVDs deliver outsized economic value relative to their cost:

• Cost avoidance through early detection: Early-stage cancer treatment costs a fraction of late-stage treatment. A breast cancer detected at Stage I may cost approximately $30,000-50,000 to treat, compared to $150,000-300,000 for Stage IV disease.
• Reduced hospitalizations: Point-of-care IVDs that enable rapid diagnosis in emergency departments, urgent care clinics, and physician offices reduce unnecessary hospital admissions and shorten length of stay.
• Targeted therapy: By identifying patients who will benefit from expensive targeted therapies (and excluding those who will not), companion diagnostics reduce wasted pharmaceutical spending while improving outcomes.
• Population health management: Screening programs using IVDs (e.g., newborn screening panels, prenatal screening, cancer screening) identify at-risk individuals before they develop costly complications.

Key insight: When building a business case for an IVD product, quantify not only the direct clinical benefit but also the downstream economic impact — reduced hospitalizations, avoided treatments, shortened time to diagnosis, and improved population health outcomes. Regulators, payers, and health technology assessment (HTA) bodies increasingly expect this type of value evidence alongside traditional analytical and clinical performance data.

Are IVDs Considered Medical Devices?

The short answer is yes — in every major regulatory jurisdiction, IVDs are legally classified as medical devices. This distinction matters because it subjects IVD manufacturers to the full range of medical device regulatory requirements: premarket review or conformity assessment, quality system compliance, establishment registration and device listing, labeling requirements, post-market surveillance, and adverse event reporting.

The FDA defines IVDs as a subset of medical devices in Section 201(h) of the FD&C Act. The IVDR defines an IVD medical device in Article 2(2) as "any medical device which is a reagent, reagent product, calibrator, control material, kit, instrument, apparatus, piece of equipment, software or system, whether used alone or in combination, intended by the manufacturer to be used in vitro for the examination of specimens, including blood and tissue donations, derived from the human body."

The reason IVDs have their own regulations (21 CFR Part 809 in the US, Regulation (EU) 2017/746 in the EU) rather than simply falling under the general medical device framework is that the risk profile is fundamentally different. A pacemaker risks mechanical failure inside the body. A blood glucose monitor risks giving a wrong number that causes a patient to administer an incorrect insulin dose. The consequences can be equally severe, but the nature of risk — and therefore the type of evidence needed to demonstrate safety and effectiveness — is different.

This distinction also means that IVDs often face dual regulatory considerations. In the US, an IVD must satisfy both FDA requirements (premarket clearance or approval) and CLIA requirements (complexity categorization for laboratory testing). In the EU, an IVD must comply with the IVDR and, if it incorporates AI, potentially the EU AI Act as well.

Types of IVD Devices

IVDs span an enormous range of technologies, specimen types, and clinical applications. Understanding the major categories is essential for regulatory strategy because classification, predicate selection, performance evaluation, and applicable standards all depend on the type of IVD.

Clinical Chemistry

Clinical chemistry analyzers and reagents measure chemical constituents in body fluids — glucose, electrolytes (sodium, potassium, chloride), enzymes (ALT, AST, creatine kinase), lipids (cholesterol, triglycerides, HDL, LDL), proteins (albumin, total protein), metabolites (creatinine, urea, bilirubin), and therapeutic drug levels. These tests form the backbone of routine laboratory medicine and are typically run on high-throughput automated platforms. Clinical chemistry represents the largest volume of laboratory testing globally, with a well-established base of predicate devices and recognized consensus standards for validation.

Immunoassay / Immunochemistry

Immunoassay-based IVDs use antigen-antibody reactions to detect and quantify specific analytes. This category includes hormone assays (thyroid hormones, cortisol, insulin, HCG), tumor markers (PSA, CA-125, CEA, AFP), cardiac biomarkers (troponin, BNP, CK-MB), infectious disease serology (HIV antibodies, hepatitis B surface antigen, SARS-CoV-2 antibodies), therapeutic drug monitoring, and allergy testing (specific IgE). Technologies range from enzyme-linked immunosorbent assays (ELISA) to chemiluminescent immunoassays (CLIA platforms), fluorescence immunoassays, and lateral flow immunoassays. The diversity of immunoassay formats creates particular challenges for cross-reactivity testing and method comparison studies.

Molecular Diagnostics

Molecular diagnostics detect and analyze nucleic acids (DNA and RNA) to diagnose disease, identify pathogens, guide therapy, and monitor treatment response. This is the fastest-growing segment of the IVD market and includes PCR (polymerase chain reaction) assays, real-time RT-PCR, isothermal amplification (e.g., LAMP), next-generation sequencing (NGS) panels, digital PCR, in situ hybridization (FISH, CISH), and microarray-based assays. Applications span infectious disease (pathogen identification, viral load quantification, resistance genotyping), oncology (companion diagnostics, liquid biopsy, minimal residual disease), pharmacogenomics, prenatal screening (NIPT), and genetic disease testing.

Molecular diagnostics present unique regulatory challenges. NGS-based assays, for example, may detect hundreds or thousands of variants simultaneously, raising questions about how to validate each analyte and what level of clinical evidence is needed for each claimed variant. The FDA has addressed this through its 2018 guidance on NGS-based oncology tests and through the use of curated genomic databases as a form of clinical evidence.

Hematology

Hematology IVDs perform complete blood counts (CBC), differential white blood cell counts, platelet counts, reticulocyte counts, and hemoglobin measurements. Automated hematology analyzers and their associated reagents, calibrators, and controls constitute this category. Coagulation testing (PT/INR, aPTT, D-dimer, fibrinogen) is a closely related subcategory.

Microbiology

Microbiology IVDs identify microorganisms (bacteria, viruses, fungi, parasites) from clinical specimens. This category includes culture media, identification panels, antimicrobial susceptibility testing (AST) systems, blood culture instruments, and rapid antigen tests for infectious agents. The transition from culture-based methods to molecular and mass spectrometry-based identification (e.g., MALDI-TOF) has reshaped this segment.

Blood Banking / Transfusion Medicine

Blood banking IVDs include blood grouping reagents (ABO, Rh typing), antibody screening and identification systems, crossmatch reagents, and nucleic acid testing (NAT) for transfusion-transmitted infections (HIV, HCV, HBV, Zika). These products occupy the highest risk categories in both the FDA and EU IVDR classification systems because errors can directly cause transfusion reactions and death.

Histology and Cytology

This category includes tissue processing reagents, embedding media, staining reagents (H&E, special stains, immunohistochemistry), mounting media, and associated instruments used in anatomical pathology and cytology. Companion diagnostics that use immunohistochemistry (e.g., HER2 IHC, PD-L1 IHC) bridge histology and molecular diagnostics.

Urinalysis

Urinalysis IVDs include urine dipstick tests (for glucose, protein, blood, leukocytes, nitrites, pH, ketones, bilirubin, and specific gravity), automated urine chemistry analyzers, and urine sediment analyzers. These are among the most commonly performed and widely accessible IVD tests, frequently used in point-of-care settings.

Point-of-Care Testing (POCT) and Self-Testing

Point-of-care IVDs are designed to be used at or near the site of patient care — in emergency departments, clinics, pharmacies, ambulances, or patients' homes — rather than in centralized laboratories. Self-testing IVDs are intended for use by lay persons. Examples include blood glucose meters, home pregnancy tests, home HIV tests, rapid strep tests, flu/COVID rapid antigen tests, and INR self-monitoring devices.

The key regulatory distinction for POCT and self-testing devices is the intended user. A test designed for use by laboratory professionals faces different usability, labeling, and validation requirements than a test designed for a nurse at a patient's bedside, which in turn faces different requirements than a test designed for a consumer at home. This distinction affects classification, CLIA categorization (US), design validation, labeling language, and the scope of human factors studies.

IVD Market Overview and Trends

The global IVD market has matured significantly since the explosive pandemic-era growth of 2020-2022. Key trends shaping the industry in 2025-2026 include:

• Market size: The global IVD market was valued at approximately USD 104 billion in 2025 and is projected to grow at a compound annual growth rate (CAGR) of 5-6%, reaching approximately USD 136 billion by 2035. The United States remains the largest single market, followed by Europe, China, and Japan.
• Molecular diagnostics growth: Molecular diagnostics remains the fastest-growing segment, driven by expanded use of NGS-based companion diagnostics, liquid biopsy for early cancer detection and minimal residual disease monitoring, and multiplex respiratory panels that test for 20+ pathogens simultaneously. Digital PCR and CRISPR-based diagnostics are emerging as next-generation platforms.
• Point-of-care expansion: The COVID-19 pandemic permanently expanded the point-of-care and at-home testing market. Consumers and healthcare systems now expect rapid, decentralized testing for a wider range of conditions. This trend extends beyond infectious disease to include cardiac biomarkers, HbA1c, lipid panels, and multi-analyte wellness panels.
• AI/ML integration: Artificial intelligence and machine learning are being embedded into IVD platforms for image analysis (digital pathology, microscopy), data interpretation (variant calling in NGS, multi-analyte pattern recognition), predictive analytics (risk stratification), and workflow optimization (automated quality control, smart specimen routing).
• Companion diagnostics: The precision medicine paradigm continues to drive demand for companion diagnostics, particularly in oncology, where targeted therapies increasingly require a matched diagnostic test. The expansion of immunotherapy and the growing number of actionable genomic targets are fueling demand for comprehensive genomic profiling panels.
• Liquid biopsy: Non-invasive cancer detection and monitoring through circulating tumor DNA (ctDNA) analysis is one of the most active areas of IVD development. Applications include early cancer detection, treatment selection, monitoring for minimal residual disease, and detection of resistance mutations.
• Decentralization of testing: The shift from centralized laboratory testing to near-patient and home testing is accelerating, with implications for device design, usability, regulatory classification, and quality assurance. Microfluidics, lab-on-chip technologies, and smartphone-connected biosensors are enabling increasingly sophisticated testing outside the laboratory.
• Antimicrobial resistance: The growing global threat of antimicrobial resistance (AMR) is driving demand for rapid antimicrobial susceptibility testing (AST) and pathogen identification systems that can guide targeted antibiotic therapy within hours rather than days.
• Regulatory convergence: International harmonization efforts through the IMDRF and bilateral recognition agreements are gradually reducing duplication of regulatory submissions across markets. The MDSAP (Medical Device Single Audit Program) — recognized by the US, Canada, Australia, Japan, and Brazil — is particularly valuable for IVD manufacturers seeking multi-market access through a single quality system audit.

FDA Regulatory Framework for IVDs

IVDs Are Medical Devices Under Federal Law

In the United States, IVDs are regulated as medical devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act). Section 201(h) of the FD&C Act defines a medical device broadly enough to encompass IVDs, and the FDA's Center for Devices and Radiological Health (CDRH) has primary jurisdiction over most IVD products. Within CDRH, the Office of In Vitro Diagnostics (OHT7) handles the review and regulation of IVDs, including clinical chemistry, toxicology, hematology, pathology, immunology, and microbiology devices.

It is worth noting that certain IVDs — particularly those derived from or closely related to biological products, such as blood grouping reagents and certain allergen extracts — fall under the jurisdiction of the FDA's Center for Biologics Evaluation and Research (CBER) rather than CDRH. Additionally, IVD products that are used in conjunction with blood and blood components may be regulated under both the FD&C Act and the Public Health Service Act (Section 351).

The FDA defines in vitro diagnostic products as:

"Those reagents, instruments, and systems intended for use in diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body." — 21 CFR 809.3

The specific regulatory requirements for IVDs are found in 21 CFR Part 809 (In Vitro Diagnostic Products for Human Use), which establishes labeling requirements, establishment registration, device listing, and good manufacturing practice obligations. IVDs are also subject to the same general device requirements as other medical devices — 21 CFR Part 820 (Quality System Regulation, transitioning to QMSR), Part 803 (Medical Device Reporting), Part 806 (Reports of Corrections and Removals), and Part 807 (Establishment Registration and Device Listing).

FDA Device Classification for IVDs

The FDA classifies all medical devices — including IVDs — into three regulatory classes based on the level of control necessary to provide reasonable assurance of safety and effectiveness:

Class	Risk Level	Controls Required	Typical IVD Examples
Class I	Low risk	General controls only	Specimen collection containers, manual pipettes, certain calibrators, tongue depressors
Class II	Moderate risk	General controls + special controls	Blood glucose monitors, pregnancy tests, cholesterol tests, rapid strep tests, hematology analyzers, immunoassay systems
Class III	High risk	General controls + premarket approval (PMA)	HIV screening tests, HCV/HBV NAT for blood screening, companion diagnostics (currently; see reclassification below), high-risk infectious disease tests

For IVDs, risk classification hinges on a fundamentally different question than for therapeutic devices. The risk is not about physical harm from device-body interaction. It is about the consequences of an incorrect test result. What happens if the test produces a false negative for HIV? What happens if a companion diagnostic incorrectly identifies a patient as ineligible for a targeted cancer therapy? The severity of these consequences determines classification.

Each IVD product type is assigned a three-letter product code and a corresponding regulation number in 21 CFR Parts 862-892. The product code is the most granular identifier in the FDA classification system and determines the specific regulatory requirements, special controls (if Class II), and predicate landscape for your device.

Practical tip: To find the classification of your IVD, start with the FDA Product Classification Database. Search by device name, product code, or regulation number. If you are genuinely uncertain about your device's classification, you can submit a 513(g) Request for Information to obtain a formal determination from the FDA.

FDA IVD Pathways to Market

IVDs follow the same premarket pathways as other medical devices. The pathway depends on the device's classification, the availability of predicate devices, and the risk profile.

510(k) Premarket Notification

The 510(k) is the pathway for most Class II IVDs and for certain Class I IVDs that are not exempt from premarket notification. In a 510(k), the manufacturer must demonstrate that the new IVD is substantially equivalent to a legally marketed predicate device in terms of intended use and technological characteristics.

For IVDs, the 510(k) review focuses heavily on analytical performance data:

• Accuracy/bias — Agreement between the new device and a reference method or the predicate device
• Precision — Repeatability (within-run) and reproducibility (between-run, between-day, between-site, between-lot)
• Analytical sensitivity — Limit of detection (LoD), limit of quantitation (LoQ)
• Analytical specificity — Interference testing, cross-reactivity (for microbiology and immunoassay)
• Linearity and reportable range — For quantitative assays
• Method comparison — Head-to-head comparison with the predicate or a recognized reference method using clinical specimens

In most cases, analytical studies using clinical specimens are sufficient to demonstrate substantial equivalence. Prospective clinical studies are rarely required in a 510(k) for IVDs but are not out of the question, particularly when the intended use differs from the predicate or when clinical performance claims are made.

Premarket Approval (PMA)

PMA is required for Class III IVDs — devices for which general controls and special controls are insufficient to provide reasonable assurance of safety and effectiveness. The PMA application requires valid scientific evidence demonstrating both safety and effectiveness, which typically means comprehensive analytical and clinical performance data, including prospective clinical studies.

PMA is the most rigorous and expensive premarket pathway. In FY 2025, the standard PMA user fee was approximately $540,783, compared to approximately $24,335 for a 510(k). The review timeline is also significantly longer — typically 180 days for a PMA decision versus 90 days for a 510(k) — and PMA review often involves advisory committee meetings.

For IVDs, the safety determination in a PMA focuses on the consequences of false positive and false negative results. The FDA evaluates whether the analytical and clinical performance of the device — including diagnostic sensitivity, diagnostic specificity, positive and negative predictive values — are sufficient to support the claimed intended use without exposing patients to unreasonable risk from incorrect results.

PMA supplements are required for significant changes to a PMA-approved device, including changes to intended use, analytical performance claims, reagent formulation, or manufacturing processes.

De Novo Classification

The De Novo pathway is for novel IVDs that are low-to-moderate risk (appropriate for Class I or Class II) but have no legally marketed predicate device. A successful De Novo classification creates a new regulatory classification and product code, and the device becomes a predicate for future 510(k) submissions.

Many innovative IVD technologies — novel biomarkers, first-of-kind molecular assays, new point-of-care platforms — enter the market through the De Novo pathway. Recent examples include the first FDA-authorized liquid biopsy tests, first-of-kind pharmacogenomic panels, and novel at-home specimen collection devices.

The De Novo process requires the same type of performance data as a 510(k) or PMA (depending on the complexity of the device), plus a risk-based classification recommendation that proposes the appropriate class and the special controls (if Class II) needed to mitigate the identified risks. The FDA review timeline for a De Novo is typically 150 days but can vary significantly.

Emergency Use Authorization (EUA)

During a declared public health emergency, the FDA can authorize unapproved IVDs for emergency use. The COVID-19 pandemic saw hundreds of EUAs issued for SARS-CoV-2 diagnostic tests (molecular, antigen, serology), demonstrating both the flexibility and the limitations of the EUA framework. EUAs are temporary authorizations that expire when the emergency declaration ends, at which point manufacturers must pursue standard premarket clearance or approval.

Pre-Submission (Pre-Sub) Program

The FDA's Pre-Submission program allows IVD manufacturers to request formal feedback from the agency before filing a regulatory submission. Pre-Subs are voluntary but highly recommended when:

• The device involves new technology, a novel intended use, or a new analyte
• The regulatory pathway is unclear
• Study designs involve complex data or statistical approaches
• The predicate or reference method is uncertain
• The device is a multiplex assay testing many analytes simultaneously

A well-executed Pre-Sub can prevent months of wasted work by aligning your study design with FDA expectations before you invest in validation studies.

IVDs and Investigational Device Exemptions (IDE)

In the US, an investigational device exemption (IDE) is typically required before a medical device that has not been cleared for marketing can be used in a clinical investigation involving human subjects. However, due to the nature of IVDs, many are exempt from the requirement to obtain an IDE before pursuing a clinical study.

IVDs are exempt from IDE requirements (per 21 CFR 812.2(c)(3)) if their testing:

• Is noninvasive
• Does not require an invasive sampling procedure that presents significant risk
• Does not by design or intention introduce energy into a subject
• Is not used as a diagnostic procedure without confirmation by another medically established diagnostic product or procedure

In practice, this means that most IVD clinical studies — where specimens are collected as part of routine care and tested alongside standard-of-care methods — do not require an IDE. The results of the investigational IVD are not used to make clinical decisions about the patient's care. However, even IDE-exempt devices must comply with specific labeling requirements per 21 CFR 809.10(c)(9) during the study, including the statement "For Investigational Use Only."

If the investigational IVD will be used to make clinical decisions (i.e., the physician will act on the test results), an IDE is required, and the manufacturer must submit an IDE application to the FDA and obtain IRB approval before beginning the study.

Practical tip: Even when an IDE is not required, you still need Institutional Review Board (IRB) or Ethics Committee approval for studies involving human specimens. The IRB reviews the study protocol, informed consent procedures, and specimen handling to protect patient rights and welfare.

CLIA and CLIA Waiver for IVDs

The Clinical Laboratory Improvement Amendments of 1988 (CLIA) — codified at 42 USC 263a and implementing regulations at 42 CFR Part 493 — establish quality standards for all laboratory testing performed on human specimens in the United States. CLIA is administered by the Centers for Medicare & Medicaid Services (CMS), not the FDA, but the two frameworks intersect directly for IVDs.

Every IVD test performed in a clinical setting in the United States must be categorized under one of three CLIA complexity levels:

CLIA Category	Description	Laboratory Requirements	Examples
Waived	Simple tests with negligible risk of erroneous results	Certificate of Waiver; follow manufacturer's instructions; no personnel qualifications or proficiency testing required	Home pregnancy tests, fecal occult blood tests, certain blood glucose monitors, rapid strep tests, certain rapid flu/COVID tests
Moderate complexity	Tests requiring some training and quality control	Certificate of Compliance or Accreditation; qualified personnel; quality control; proficiency testing required	Most automated chemistry, hematology, and immunoassay analyzers; most microbiology culture systems
High complexity	Tests requiring significant training, judgment, and interpretation	Certificate of Compliance or Accreditation; highly qualified personnel (pathologist, PhD, specialist); extensive QC and PT	Manual cell differentials, cytogenetics, flow cytometry, histopathology interpretation, many molecular assays

CLIA waiver is particularly important for point-of-care and self-testing IVDs. A CLIA-waived test can be performed in settings outside of a traditional laboratory — physician offices, pharmacies, clinics, nursing homes, and even at home — without meeting the personnel, quality control, and proficiency testing requirements that apply to moderate and high complexity testing. For manufacturers, obtaining a CLIA waiver dramatically expands the potential market and user base for their IVD.

To obtain a CLIA waiver, manufacturers must submit a CLIA waiver application to the FDA demonstrating that the test is "simple" and has "an insignificant risk of an erroneous result." The FDA evaluates the test's ease of use, the risk profile, and the results of a CLIA waiver study (typically conducted at intended-use sites by intended users with no laboratory training).

Key point: FDA clearance/approval and CLIA categorization are separate regulatory determinations. A device can be 510(k)-cleared but categorized as moderate complexity under CLIA. Conversely, a device can be CLIA-waived but still requires 510(k) clearance. Manufacturers seeking the broadest market access typically pursue both 510(k) clearance and CLIA waiver simultaneously.

Laboratory Developed Tests (LDTs)

Laboratory Developed Tests are IVDs that are designed, manufactured, and used within a single clinical laboratory. They are not sold as commercial kits. LDTs have historically occupied a unique regulatory position: although they meet the statutory definition of a medical device, the FDA has exercised enforcement discretion over LDTs for decades, meaning the agency chose not to enforce most device requirements (registration, listing, premarket review, QSR compliance) against laboratories that developed and used their own tests.

The 2024 Final Rule and Its Reversal

In May 2024, the FDA published a final rule to phase out enforcement discretion for LDTs over a four-year period, with the goal of regulating LDTs under the same framework as commercial IVDs. The rule would have required laboratories to comply with medical device reporting (Stage 1), registration, listing, and labeling (Stage 2), quality system requirements (Stage 3), and eventually premarket review (Stages 4-5).

However, this rule was struck down. On March 31, 2025, a federal court vacated the final rule, holding that LDTs are not "devices" under the FD&C Act and that the FDA exceeded its statutory authority. On September 19, 2025, the FDA published a new rule reverting the text of 21 CFR 809.3(a) to its pre-2024 language, removing the phrase "including when the manufacturer of these products is a laboratory."

Current Status (2026)

As of early 2026, the status quo has been restored: the FDA continues to exercise enforcement discretion over LDTs. Laboratories are not required to seek FDA clearance or approval for their tests, and LDTs remain regulated primarily by CMS under CLIA, and by state-level regulatory bodies (notably New York CLEP).

This does not mean LDTs are unregulated. They must comply with CLIA requirements, including analytical validation, quality control, proficiency testing, and personnel qualifications. However, the level of clinical evidence, post-market surveillance, and manufacturing controls required for LDTs remains significantly less than what is required for commercially marketed IVDs.

Industry perspective: The LDT regulatory landscape remains unsettled. The court ruling addressed the FDA's rulemaking authority, but it did not resolve the underlying question of whether LDTs should face the same regulatory scrutiny as commercial IVDs. Congressional action (such as the proposed VALID Act) could still establish a legislative framework for LDT oversight. Manufacturers and laboratories should monitor this space closely.

FDA Reclassification of High-Risk IVDs

In a significant regulatory development, the FDA has initiated the reclassification of many high-risk (Class III) IVD product types to Class II. The most prominent action is the November 2025 proposed order to reclassify oncology nucleic acid-based companion diagnostic test systems from Class III to Class II.

This proposal, if finalized, would allow manufacturers of these companion diagnostics to use the 510(k) pathway rather than the PMA pathway — dramatically reducing cost (PMA user fee: ~$541,000 vs. 510(k) user fee: ~$24,000), shortening review timelines, and lowering the evidentiary burden.

The FDA's rationale is that these technologies are now mature and well-characterized, and that special controls (analytical validation requirements, performance specifications, quality system parameters) are sufficient to provide reasonable assurance of safety and effectiveness without the need for full PMA review.

The reclassification extends beyond companion diagnostics. The FDA has proposed down-classifying most Class III IVD product types across infectious disease testing, blood screening, and other categories, reflecting a broader strategic shift toward 510(k)-based regulation for IVDs.

What this means for manufacturers: If your IVD is currently Class III, check whether your product code is included in the FDA's reclassification proposals. If it is, you may be able to plan for a 510(k) pathway rather than PMA for future products or modifications. Monitor the Federal Register and the FDA's IVD guidance page for final rules.

IVD Labeling Requirements (21 CFR 809)

IVD labeling is subject to both the general medical device labeling requirements (21 CFR Part 801) and the IVD-specific requirements in 21 CFR Part 809, Subpart B. Labeling deficiencies are among the most common reasons for FDA refuse-to-accept (RTA) decisions and 510(k) additional information requests. Getting labeling right from the start can prevent significant delays.

What Must Appear on the IVD Label

Under 21 CFR 809.10, the following information must appear on the label (the immediate container label and/or the outer packaging):

• Proprietary name and established name (common or usual name) of the device
• Intended use — a clear statement of the device's intended use, including the specific analyte(s) detected or measured, the clinical purpose, the specimen type(s), and the intended user population
• Reagent identity and quantity — for reagent products, the established name and quantity, proportion, or concentration of each reactive ingredient, expressed in the measurement system recognized by the intended user (metric, international units, etc.)
• Warnings and precautions — statements of warnings or precautions for users, including biohazard warnings for products containing or intended for use with human-derived materials
• Storage and handling instructions — conditions of temperature, light, humidity, and other factors necessary to protect stability
• Date of manufacture and expiration date — adequate to ensure the product is used within its validated shelf life
• Net quantity of contents — for reagent kits and multi-component systems
• Name and address of manufacturer, packer, or distributor
• Lot or batch number — traceable to manufacturing records

What Must Appear in the Instructions for Use (IFU)

The IFU (also called the package insert or directions for use) is more extensive and must include:

• Intended use statement — identical to or consistent with the intended use in the regulatory submission
• Summary and explanation of the test — the clinical significance of the analyte and the scientific basis of the test methodology
• Principle of the procedure — how the test works (chemical, immunological, molecular, or other methodology)
• Reagent description — complete description of all reagents, including composition, preparation instructions, and stability information
• Instruments and materials required but not provided — equipment, consumables, and ancillary materials needed to perform the test
• Specimen collection and preparation — acceptable specimen types, collection methods, handling, storage, and stability requirements for patient specimens
• Test procedure — step-by-step instructions, including calibration, quality control, and sample processing
• Results interpretation — how to read, calculate, and interpret results, including the clinical significance of positive, negative, and indeterminate results
• Limitations of the procedure — known limitations, potential interfering substances, conditions that may affect test performance
• Expected values — reference ranges or expected results in defined populations (normal and abnormal)
• Specific performance characteristics — analytical and clinical performance data, including accuracy, precision, analytical sensitivity (LoD), analytical specificity, linearity, and clinical sensitivity/specificity, as established against a generally accepted reference method using specimens from normal and abnormal populations
• Bibliography — references supporting the scientific validity and performance claims

IVDR Labeling Requirements

Under the IVDR, labeling requirements are specified in Annex I (General Safety and Performance Requirements, Chapter III) and must include the information listed above plus additional EU-specific elements:

• UDI carrier — the UDI-DI and UDI-PI in both human-readable and machine-readable (barcode/RFID) format
• CE marking — with the four-digit Notified Body number (for devices requiring Notified Body assessment)
• Authorized representative information — for manufacturers established outside the EU
• Symbols — per ISO 15223-1 (Symbols to be used with information to be supplied by the manufacturer) and EN ISO 18113 (IVD-specific labeling)
• Language requirements — labels and IFU must be in the official language(s) of the EU member state(s) where the device is made available
• Electronic IFU (eIFU) — the IVDR permits electronic instructions for use under specific conditions (Regulation (EU) 2021/2226), provided the manufacturer ensures accessibility and offers paper versions on request

Practical tip: Build your labeling templates early in development, aligned with both FDA and IVDR requirements. Use ISO 15223-1 symbols and EN ISO 18113 IVD-specific symbols from the start — these are accepted in both the US and EU and reduce the need for translated text. Validate your labeling with actual users as part of usability testing.

EU IVDR Classification System

From IVDD to IVDR

The In Vitro Diagnostic Regulation (EU) 2017/746 — the IVDR — replaced the In Vitro Diagnostic Medical Devices Directive (IVDD 98/79/EC) and has been applicable since May 26, 2022. The transition from IVDD to IVDR represents the most significant overhaul of IVD regulation in European history.

Under the IVDD, IVDs were classified using a list-based system: Annex II List A (highest risk, e.g., blood group typing, HIV/HCV testing), Annex II List B (moderate-high risk, e.g., PSA testing, rubella testing), self-testing devices, and all other IVDs. Critically, approximately 80% of IVDs could be self-certified by the manufacturer — no Notified Body involvement was required. Only Annex II List A, List B, and self-testing devices needed Notified Body assessment.

The IVDR fundamentally changed this. It introduced a risk-based classification system with four classes (A, B, C, D) and seven classification rules, dramatically expanded Notified Body involvement, imposed structured performance evaluation requirements, and strengthened post-market surveillance obligations.

The Four Risk Classes

The IVDR classifies IVDs into four risk classes based on both individual patient risk and public health risk:

Class	Risk Level	Notified Body Required?	Examples
Class A	Low individual and low public health risk	No (unless sterile)	Specimen receptacles, wash buffers, general laboratory instruments, culture media for general purpose, clinical chemistry reagents for non-critical analytes
Class B	Moderate individual and/or low public health risk	Yes	Pregnancy tests, fertility tests, cholesterol self-tests, HbA1c tests, controls without quantitative assigned values, devices not covered by other rules (default class)
Class C	High individual and/or moderate public health risk	Yes	Companion diagnostics, blood glucose self-monitoring, tests detecting sexually transmitted agents (e.g., chlamydia, gonorrhea), cancer screening tests, tests detecting infectious agents without high risk of propagation, HLA typing
Class D	High individual and high public health risk	Yes (plus batch verification for certain devices)	HIV/HCV/HBV screening tests, blood grouping reagents (ABO, Rh), tests detecting transmissible agents in blood/tissue donations, tests for life-threatening diseases with high risk of propagation

The Seven Classification Rules

The IVDR's classification system is implemented through seven rules in Annex VIII. Understanding these rules is essential for determining your device's class:

Rule 1 — Devices intended to detect transmissible agents in blood, blood components, cells, tissues, or organs, or their derivatives, to assess suitability for transfusion, transplantation, or cell administration, or to detect or quantify a transmissible agent causing a life-threatening disease with a high risk of propagation = Class D.

Rule 2 — Devices for blood grouping or tissue typing to ensure immunological compatibility of blood, blood components, cells, tissues, or organs for transfusion, transplantation, or cell administration = Class C (with some Class D exceptions for certain ABO, Rh, and Kell grouping and certain anti-erythrocyte antibody systems).

Rule 3 — Devices intended for:

• Detecting the presence of, or exposure to, a sexually transmitted agent = Class C
• Detecting the presence of, or exposure to, an infectious agent in cerebrospinal fluid or blood = Class C
• Detecting the presence of an infectious agent where a false result could cause death or severe disability to the tested individual or offspring = Class C
• Prenatal screening of women to determine immune status toward transmissible agents = Class C
• Determining infectious disease status or immune status where a false result could lead to a patient management decision resulting in an imminent life-threatening situation = Class C
• Cancer screening or diagnosis = Class C
• Genetic testing in humans = Class C
• Monitoring drug levels, substances, or biological parameters where deviation leads to an imminent life-threatening situation = Class C
• Managing patients suffering from life-threatening infectious diseases = Class C
• Cancer screening as a companion diagnostic = Class C

Rule 4 — Devices for self-testing = Class C, except: pregnancy tests, fertility tests, tests for determining cholesterol level, tests for detecting glucose, erythrocytes, leucocytes, and bacteria in urine = Class B.

Rule 5 — Products for general laboratory use, accessories which possess no critical characteristics, buffer solutions, wash solutions, general culture media, and histological staining designed by the manufacturer for specific procedures, specimen receptacles = Class A.

Rule 6 — IVDs not covered by Rules 1-5 = Class B (default classification).

Rule 7 — Devices that are controls without a quantitative or qualitative assigned value = Class B.

Important: If a device falls under multiple classification rules, the highest class applies. If a device has multiple intended purposes spanning different classes, it must be classified in the highest applicable class.

IVDR Transition Timeline and Current Status

The transition from IVDD to IVDR has been challenging for the industry. The European Commission recognized that many IVD manufacturers — especially smaller companies — and Notified Bodies could not meet the original May 2022 application date, leading to extended transition periods:

Device Class	Application Deadline for Notified Body	Sell-Through Deadline
Class D	May 26, 2025	May 26, 2027
Class C	May 26, 2026	May 26, 2028
Class B and Class A sterile	May 26, 2027	May 26, 2029

These deadlines apply to "legacy" devices — IVDs that were lawfully placed on the EU market under the IVDD and that have a valid IVDD certificate or IVDD self-declaration. Manufacturers of these devices must have applied to a Notified Body by the relevant deadline. The "sell-through" deadline is the last date that non-IVDR-compliant devices may continue to be made available on the market.

New devices — IVDs without an IVDD history that are being placed on the EU market for the first time — must fully comply with the IVDR from day one. There is no transitional relief for new market entrants.

EUDAMED

The European Database on Medical Devices (EUDAMED) is a critical component of the IVDR framework. Following the publication of decision (EU) 2025/2371, four EUDAMED modules become mandatory on May 28, 2026. Devices placed on the market before that date must be registered in the UDI/Device module by November 28, 2026. EUDAMED will serve as the central system for device registration, UDI management, Notified Body certificates, clinical performance studies, vigilance reporting, and market surveillance.

Notified Body Capacity

One of the most significant practical challenges in the IVDR transition is Notified Body capacity. Under the IVDD, only about 20% of IVDs required Notified Body involvement. Under the IVDR, approximately 80% of IVDs (all Class B, C, and D devices, plus Class A sterile) require Notified Body assessment. This has created a significant bottleneck.

As of early 2026, only a limited number of Notified Bodies have been designated for the IVDR. The capacity constraint affects:

• Application processing times — Manufacturers may wait months before a Notified Body can begin reviewing their submission
• Audit scheduling — Quality system audits must be coordinated around limited auditor availability
• Legacy device transitions — Manufacturers with large portfolios of legacy devices must prioritize which products to transition first

Strategic advice: If you have not yet engaged a Notified Body for your IVDR transition, do so immediately. Establish a transition plan that prioritizes your highest-revenue and highest-risk devices first. Consider whether portfolio rationalization — discontinuing low-volume products rather than transitioning them — makes business sense.

December 2025 Simplification Proposal

On December 16, 2025, the European Commission presented a comprehensive legislative proposal to simplify the MDR and IVDR regulatory frameworks. This proposal aims to address system bottlenecks, reduce administrative burden, and strengthen innovation capacity. However, it does not amend or extend the IVDR transitional periods. The legislative process for this proposal is expected to take several years.

Key elements of the simplification proposal that affect IVDs include:

• Streamlined conformity assessment procedures for lower-risk devices
• Simplified documentation requirements for legacy devices with demonstrated safety records
• Enhanced digital tools and electronic submission capabilities through EUDAMED
• Clearer guidance on performance evaluation expectations by device class
• Improved coordination between Notified Bodies to reduce capacity bottlenecks

Manufacturers should monitor the legislative process but should not delay IVDR compliance in anticipation of these changes. The transitional deadlines remain unchanged.

IVDR and the IVDD: What Changed and Why It Matters

The transition from the IVDD to the IVDR is not a minor regulatory update — it is a fundamental restructuring of how IVDs are regulated in Europe. Understanding the magnitude of these changes is critical for manufacturers planning their transition strategy.

Aspect	IVDD (98/79/EC)	IVDR (2017/746)
Legal instrument	Directive (transposed by each EU member state)	Regulation (directly applicable across all EU member states)
Classification system	List-based (Annex II List A/B, self-testing, other)	Risk-based, four classes (A, B, C, D) with seven rules
Notified Body involvement	~20% of IVDs (Annex II List A/B and self-testing only)	~80% of IVDs (all except Class A non-sterile)
Performance evaluation	Required but not structurally defined; limited guidance	Structured three-pillar framework (scientific validity, analytical performance, clinical performance) with detailed requirements in Annex XIII
Clinical evidence	Literature review broadly accepted; clinical studies rare	Clinical performance studies required for higher-risk classes; literature must be systematic
Post-market surveillance	PMS required but loosely defined	Structured PMS with defined deliverables (PMSR, PSUR, PER, PMPF) and timelines
UDI	Not required	Required for all IVDs; EUDAMED-based
Common Specifications	Common Technical Specifications for List A devices	Common Specifications for Class D devices; broader scope
In-house devices	Largely unregulated	Article 5(5) requirements: justification, QMS, no equivalent on market
Economic operators	Limited obligations for importers/distributors	Explicit obligations for importers, distributors, and authorized representatives

The practical impact for manufacturers is enormous. A company that previously self-certified 90% of its IVD portfolio under the IVDD may now need Notified Body assessment for 80% or more of those same devices. The technical documentation requirements are significantly more extensive. The post-market obligations are more structured and resource-intensive. And the timeline pressure is real: deadlines for Notified Body applications have already passed (Class D in May 2025) or are imminent (Class C in May 2026).

Supply Chain Obligations Under the IVDR

One of the most consequential changes in the IVDR is the explicit assignment of regulatory obligations to all economic operators in the IVD supply chain — not just manufacturers. Under the IVDD, importers and distributors had minimal regulatory responsibilities. Under the IVDR, every actor in the supply chain has defined obligations, and failure to meet them can result in enforcement action by competent authorities.

Manufacturer obligations (Articles 10-12) include:

• Ensuring the device is designed and manufactured in accordance with the IVDR
• Establishing and maintaining a quality management system (ISO 13485)
• Preparing technical documentation, performance evaluation, and EU Declaration of Conformity
• Implementing post-market surveillance, vigilance reporting, and field safety corrective actions
• Assigning UDI to each device and registering devices in EUDAMED
• Maintaining economic operator registration and device listing

Authorized Representative obligations (Article 11) — manufacturers established outside the EU must appoint an authorized representative within the EU. The authorized representative acts on behalf of the manufacturer and is jointly liable for defective devices. Responsibilities include verifying that the Declaration of Conformity and technical documentation have been drawn up, maintaining device registration in EUDAMED, cooperating with competent authorities, and forwarding complaints and vigilance reports to the manufacturer.

Importer obligations (Article 13) include:

• Verifying that the device bears a CE marking and that the EU Declaration of Conformity has been drawn up
• Verifying that the manufacturer and authorized representative are identified and registered
• Ensuring that appropriate storage and transport conditions are maintained and do not compromise the device's compliance with the General Safety and Performance Requirements (GSPR)
• Maintaining a register of complaints, non-conforming devices, and recalls
• Cooperating with competent authorities and providing access to documentation upon request

Distributor obligations (Article 14) include:

• Verifying that the device bears a CE marking and the required labeling in the language(s) of the member state where the device is made available
• Verifying that the importer (if applicable) has complied with its obligations
• Ensuring that storage and transport conditions do not compromise device quality
• Informing the manufacturer, authorized representative, and/or importer of any complaints or suspected incidents
• Cooperating with corrective actions, including recalls and field safety notices

Important: Under Article 16, a distributor or importer that places a device on the market under its own name, modifies the device's intended purpose, or modifies the device in a way that affects conformity is considered a manufacturer and must assume all manufacturer obligations, including technical documentation, conformity assessment, and post-market surveillance.

These supply chain obligations require manufacturers to establish formal agreements with their distributors and importers, including quality agreements that define each party's responsibilities for storage, handling, complaint forwarding, and cooperation with vigilance activities. For IVD manufacturers selling through complex distribution networks across multiple EU member states, managing these obligations is a significant operational challenge.

Comparison: FDA IVD vs. EU IVDR Requirements

Aspect	FDA (United States)	IVDR (European Union)
Legal framework	FD&C Act, 21 CFR Part 809, 21 CFR Parts 862-892	Regulation (EU) 2017/746
Classification system	Three classes (I, II, III) based on risk	Four classes (A, B, C, D) based on patient and public health risk
Classification approach	Product-code-based (each device type has a predefined class)	Rule-based (seven classification rules in Annex VIII)
Premarket pathway	510(k), De Novo, PMA, EUA	Conformity assessment via Notified Body (except Class A non-sterile)
Notified Body / third-party review	Not applicable — FDA reviews submissions directly	Required for all IVDs except Class A non-sterile
Quality system standard	21 CFR Part 820 (QSR, transitioning to QMSR aligned with ISO 13485)	ISO 13485:2016
Performance evaluation	Analytical and clinical validation per FDA guidance; no structured three-pillar framework	Structured three-pillar framework: scientific validity, analytical performance, clinical performance (Annex XIII)
Clinical evidence	Clinical studies for PMA; analytical studies typically sufficient for 510(k)	Clinical performance studies may be required, especially for Class C and D; literature alone often insufficient
Post-market surveillance	MDR (21 CFR 803), recalls, corrections/removals	PMS plan, PMSR/PSUR, PMPF, vigilance reporting to EUDAMED
Unique Device Identification	UDI required (21 CFR Part 830)	UDI required; EUDAMED-based system
CLIA complexity	Separate CLIA categorization required (waived, moderate, high complexity)	Not applicable (no EU equivalent of CLIA)
Companion diagnostic pathway	PMA (Class III), proposed reclassification to 510(k) (Class II)	Class C under IVDR; conformity assessment by Notified Body
LDT oversight	Enforcement discretion (following 2025 court ruling)	IVDR Article 5(5) for "in-house devices" — stricter requirements than IVDD
User fees (approximate)	510(k): ~$24,000; PMA: ~$541,000	Varies by Notified Body; typically EUR 15,000-80,000+ depending on class and complexity

Pathways to Market for IVDs in the EU

Under the IVDR, the pathway to market for an IVD depends on its classification:

Class A (non-sterile): The manufacturer performs a self-assessment of conformity, prepares the technical documentation (including performance evaluation), draws up the EU declaration of conformity, and affixes the CE marking. No Notified Body is involved. This is the simplest pathway, but the manufacturer must still comply with all applicable IVDR requirements — quality management system, performance evaluation, labeling, UDI, post-market surveillance, and vigilance reporting.

Class A (sterile): Requires Notified Body assessment, but only for the aspects of manufacture related to sterility. The Notified Body audits the manufacturer's sterilization processes and validation.

Class B: Requires Notified Body conformity assessment, including review of the quality management system (ISO 13485 audit) and sampling review of the technical documentation. The Notified Body conducts initial and annual surveillance audits and reviews a sample of the manufacturer's technical files.

Class C: Requires Notified Body conformity assessment with full review of the quality management system and technical documentation for each device type. The scrutiny is more intensive than for Class B, and the Notified Body reviews the performance evaluation report, the PMS plan, and the PMPF plan in detail.

Class D: Requires the most rigorous conformity assessment, including full QMS audit, complete technical documentation review, and — for devices covered by Common Specifications — batch verification by the Notified Body. Additionally, Class D devices must have their EU reference laboratory testing or equivalent verification to ensure compliance with Common Specifications.

For all classes requiring Notified Body involvement, the manufacturer must:

1. Apply to a designated Notified Body (currently limited capacity — plan ahead)
2. Undergo a Stage 1 (documentation review) and Stage 2 (on-site) audit of the quality management system
3. Submit technical documentation for review (sampling or complete, depending on class)
4. Address any nonconformities identified during the audit or documentation review
5. Receive an ISO 13485 certificate and an IVDR certificate
6. Issue the EU Declaration of Conformity
7. Affix the CE marking to the device
8. Register the device in EUDAMED (when mandatory — May 2026)

Annual surveillance audits and periodic technical documentation reviews continue throughout the certificate validity period (typically five years).

Performance Evaluation Requirements

Performance evaluation is the process of generating and assessing data to establish or verify the scientific validity, analytical performance, and clinical performance of an IVD device. The depth and structure of performance evaluation differ between the FDA and EU frameworks, but the core questions are the same: Does this test measure what it claims to measure? How well? And does it provide clinically useful information?

Why Performance Evaluation Matters

The consequences of inadequate performance evaluation can be severe. An IVD with poor analytical specificity may produce false positive results, leading to unnecessary invasive procedures, psychological harm, and wasted healthcare resources. An IVD with poor diagnostic sensitivity may produce false negative results, causing missed diagnoses and delayed treatment for serious conditions. An IVD that has not been validated across the full range of relevant specimen types, patient populations, and pre-analytical conditions may perform well in a controlled study but fail unpredictably in real-world clinical use.

Regulators on both sides of the Atlantic have seen these failures and have responded by raising the evidence bar. The IVDR's structured three-pillar framework is a direct response to the limitations of the IVDD, where inadequate performance evaluation could go undetected because most IVDs were self-certified without external review. The FDA's increasingly detailed device-specific guidance documents reflect similar concerns.

FDA Approach

The FDA does not use the term "performance evaluation" as a structured framework. Instead, analytical and clinical validation requirements are addressed through:

• Device-specific guidance documents — The FDA publishes guidance for specific IVD types (e.g., companion diagnostics, infectious disease tests, blood glucose monitors) detailing the expected validation studies
• Recognized consensus standards — CLSI (Clinical and Laboratory Standards Institute) standards are widely used and FDA-recognized for analytical validation: EP05 (precision), EP06 (linearity), EP07 (interference), EP09 (method comparison), EP12 (qualitative test performance), EP17 (limit of detection), EP25 (user verification)
• Special controls — For Class II devices, the applicable special controls document specifies the performance characteristics that must be demonstrated

For a 510(k), the manufacturer typically submits analytical performance data (accuracy, precision, linearity, LoD, LoQ, analytical specificity, interference, method comparison) and may submit clinical agreement data showing concordance with a predicate or reference method. For a PMA, the FDA expects comprehensive clinical study data demonstrating safety and effectiveness.

IVDR Approach: The Three Pillars

The IVDR establishes a structured three-pillar performance evaluation framework in Article 56 and Annex XIII:

Pillar 1: Scientific Validity — Demonstrates the association between the analyte (or marker, or genetic variant) and the clinical condition or physiological state. This pillar is established through peer-reviewed literature, clinical practice guidelines, systematic reviews, international standards, and established medical knowledge. It is about the analyte-disease association, not the specific device.

Pillar 2: Analytical Performance — Demonstrates the device's ability to correctly detect or measure the intended analyte. Annex XIII, Part A, Section 1.2.2 lists the characteristics to evaluate: analytical sensitivity, analytical specificity, trueness/accuracy, precision (repeatability and reproducibility), limit of detection, limit of quantitation, linearity, measuring range, cut-off values, reagent stability, matrix effects, and carry-over.

Pillar 3: Clinical Performance — Demonstrates the device's ability to yield results correlated with a particular clinical condition or physiological/pathological state in the target population. Clinical performance is expressed through diagnostic sensitivity, diagnostic specificity, positive predictive value, negative predictive value, likelihood ratios, and expected values in normal and affected populations. Clinical performance studies (prospective or retrospective, interventional or observational) may be required, particularly for Class C and D devices.

All three pillars must be documented in a performance evaluation plan and a performance evaluation report (PER), updated throughout the device lifecycle.

For a deep dive into IVDR performance evaluation, including study design, documentation requirements, and what Notified Bodies expect, see our companion article: IVDR Performance Evaluation: The Complete Guide for IVD Manufacturers.

Performance Evaluation by IVDR Device Class

The depth and rigor of performance evaluation scales with device class under the IVDR:

Aspect	Class A	Class B	Class C	Class D
Performance evaluation plan	Required	Required	Required	Required
Scientific validity	Literature-based (straightforward for established analytes)	Literature-based	Comprehensive; may need systematic review	Comprehensive; systematic review expected
Analytical performance	Basic characterization	Full analytical validation	Full analytical validation with extensive studies	Full analytical validation; Common Specifications may apply
Clinical performance	May rely on published literature	Literature + clinical performance data	Clinical performance study likely required	Clinical performance study typically required; NB batch verification
Performance evaluation report	Required	Required	Required (annual update)	Required (annual update)
Notified Body review	No (unless sterile)	Yes	Yes	Yes (enhanced scrutiny)
PMPF	Justify if not conducted	Justify if not conducted	Generally expected	Expected

For Class D devices, the IVDR introduces an additional layer of oversight: Notified Body batch verification. For certain Class D devices (those covered by Common Specifications), the Notified Body must verify that each manufactured batch meets the applicable specifications before the batch can be released to the market. This is analogous to batch release for biological medicinal products and represents one of the most significant IVDR requirements with no FDA equivalent.

In-House IVDs Under the IVDR

The IVDR introduced specific requirements for "in-house devices" — IVDs that are manufactured and used within a single health institution (e.g., a hospital laboratory that develops and uses its own test). Under the IVDD, in-house devices were largely unregulated. Under IVDR Article 5(5), health institutions may manufacture and use in-house IVDs only if:

• No equivalent CE-marked IVD is available on the market, or the available CE-marked device does not meet the specific needs of the target patient group
• The health institution provides justification in its documentation
• The manufacturing follows appropriate quality management system principles (including ISO 15189)
• The device is not transferred to another legal entity
• The manufacture takes place under quality management system requirements comparable to those in the IVDR

This provision is particularly important for hospital laboratories that develop niche assays for rare diseases, novel biomarkers, or specialized patient populations where no commercial IVD exists. The requirements represent a significant increase in regulatory burden compared to the IVDD regime.

Companion Diagnostics

A companion diagnostic (CDx) is an IVD device that provides information essential for the safe and effective use of a corresponding therapeutic product. The classic example is a test that identifies whether a patient's tumor expresses a specific biomarker or carries a specific genetic mutation that makes the patient eligible (or ineligible) for a targeted therapy.

FDA Companion Diagnostic Pathway

The FDA defines an IVD companion diagnostic as "an in vitro diagnostic device that provides information that is essential for the safe and effective use of a corresponding therapeutic product." The labeling of both the diagnostic device and the therapeutic product must reference each other.

Historically, companion diagnostics were Class III devices requiring PMA. However, in November 2025, the FDA proposed reclassifying oncology nucleic acid-based companion diagnostics from Class III to Class II, which would allow manufacturers to use the 510(k) pathway. This proposed reclassification reflects the FDA's view that:

• The underlying technologies (PCR, NGS, ISH) are now mature and well-characterized
• Special controls can provide reasonable assurance of safety and effectiveness
• The 510(k) pathway would reduce barriers to market entry, increase competition, and improve patient access to companion diagnostics
• The cost reduction would be substantial (510(k) fee ~$24,000 vs. PMA fee ~$541,000)

The comment period for this proposal closed January 26, 2026. If finalized, this would be the most significant structural change to CDx oversight in more than a decade.

FDA guidance (2014, updated 2024) recommends that the companion diagnostic and the therapeutic product be developed contemporaneously, ideally with the CDx included in the therapeutic's pivotal clinical trial. However, the FDA recognizes that this is not always possible and has approved CDx after the therapeutic in some cases.

EU IVDR Companion Diagnostic Requirements

Under the IVDR, companion diagnostics are classified as Class C devices under Rule 3(h). This means they require:

• Conformity assessment by a Notified Body
• A structured performance evaluation covering all three pillars
• Post-market performance follow-up (PMPF)
• Periodic safety update reports (PSUR)

The IVDR also requires that the manufacturer of the companion diagnostic consult with the relevant competent authority or the EMA regarding the suitability of the companion diagnostic before initiating the conformity assessment process (Article 48(12)).

A key distinction: in the EU, the therapeutic product and the companion diagnostic are regulated by different legal frameworks (medicinal product vs. IVD regulation), different regulatory bodies (EMA/national competent authority vs. Notified Body), and potentially on different timelines. Coordination is essential but structurally more complex than in the FDA's integrated approach.

Companion Diagnostics vs. Complementary Diagnostics

It is important to distinguish companion diagnostics from complementary diagnostics. A companion diagnostic provides information that is essential for the safe and effective use of a drug — the drug's labeling mandates testing with the CDx. A complementary diagnostic provides information that is useful for treatment decisions but not essential — the drug can be prescribed without the test.

The classic example: EGFR mutation testing is a companion diagnostic for certain EGFR-targeted cancer therapies (the drug cannot be prescribed without a positive EGFR test). PD-L1 expression testing is often a complementary diagnostic for immune checkpoint inhibitors (the drug may be prescribed regardless of PD-L1 status, but PD-L1 results help predict the likelihood of response).

The regulatory pathway differences are significant. Companion diagnostics are subject to higher regulatory scrutiny (PMA or IVDR Class C) and must be approved or cleared before or concurrently with the therapeutic. Complementary diagnostics may follow standard IVD regulatory pathways for their technology type and risk class.

Co-Development Considerations

FDA guidance recommends co-development of the companion diagnostic and the therapeutic product. Ideally, the CDx should be used in the pivotal clinical trial for the therapeutic, so that the trial simultaneously generates clinical evidence for both the drug and the diagnostic. This approach:

• Ensures the CDx is validated on the same patient population that was studied in the pivotal trial
• Provides concordance data between the CDx and the clinical outcome (drug response)
• Enables simultaneous regulatory submissions for the drug (NDA/BLA) and the CDx (PMA or 510(k))

In practice, co-development is not always possible. The therapeutic may be approved before a CDx is available, or the original CDx used in the trial may be developed by a different manufacturer than the one seeking market authorization. The FDA has mechanisms to address these situations, including allowing bridging studies to demonstrate the equivalence of a new CDx to the one used in the pivotal trial.

Point-of-Care and Self-Testing IVDs

Point-of-care testing (POCT) and self-testing IVDs face additional regulatory requirements because they are used outside the controlled laboratory environment — by healthcare professionals who may not have laboratory training (POCT) or by lay persons with no medical or laboratory background (self-testing).

FDA Requirements

In the United States, the regulatory framework for POCT and self-testing IVDs centers on CLIA categorization:

• CLIA-waived tests can be performed in non-laboratory settings (physician offices, clinics, pharmacies, at home) with minimal oversight
• Over-the-counter (OTC) tests are self-testing IVDs sold directly to consumers without a prescription. They must be CLIA-waived and must meet specific labeling requirements (21 CFR 809.10) and human factors/usability requirements to ensure lay users can perform the test correctly

To obtain CLIA waiver, the manufacturer must demonstrate through a waiver study that the test is simple and has an insignificant risk of erroneous results. Waiver studies are typically conducted at intended-use sites (clinics, pharmacies) by intended users (medical assistants, pharmacy staff, or lay users) to evaluate ease of use, error rates, and clinical agreement with a reference method.

Human factors testing is critically important for self-testing IVDs. The FDA expects a comprehensive usability evaluation demonstrating that lay users can:

• Open the kit and identify all components
• Correctly collect the specimen
• Perform the test procedure correctly
• Interpret the results correctly
• Take appropriate follow-up action

IVDR Requirements

Under the IVDR, devices intended for self-testing are classified as Class C under Rule 4, with exceptions for pregnancy tests, fertility tests, cholesterol tests, and certain urine tests, which are classified as Class B.

The IVDR defines a "device for self-testing" as "any device intended by the manufacturer to be used by lay persons, including devices used for testing services offered to lay persons by means of information society services" (Article 2(4)).

Self-testing IVDs under the IVDR must meet additional requirements:

• Usability testing — Demonstrate that lay users can perform the test correctly and interpret results accurately
• Labeling — Instructions for use must be written in language that can be understood by lay persons, without requiring medical terminology
• Common specifications — Self-testing devices may be subject to Common Specifications (CS) established by the European Commission
• Design considerations — The device design must account for the fact that the user has no laboratory training and may perform the test in uncontrolled environments

For "near-patient testing" (NPT) devices — IVDs used at the point of care by healthcare professionals outside a laboratory setting — the IVDR does not define a separate classification category, but the device's instructions for use must specify the qualifications and training required of the intended user.

AI/ML in IVD Diagnostics

Artificial intelligence and machine learning are increasingly embedded in IVD devices — from digital pathology algorithms that analyze tissue slides to AI-driven variant callers for next-generation sequencing, from machine learning models that interpret multiplex assay data to predictive algorithms that stratify patient risk based on multi-analyte panels.

Regulatory Status

AI/ML-based IVDs are regulated as Software as a Medical Device (SaMD) and follow the same regulatory pathways as other IVDs, with additional considerations for the AI/ML component.

FDA: As of mid-2025, the FDA has authorized approximately 1,000 AI/ML-enabled medical devices, spanning radiology, cardiology, pathology, and other specialties. The FDA's January 2025 Draft Guidance on "Artificial Intelligence-Enabled Device Software Functions" establishes a Total Product Life Cycle (TPLC) approach, recommending:

• Model description, architecture, and training methodology
• Data lineage, data splits, and data quality documentation
• Performance metrics tied to clinical claims
• Bias analysis and mitigation strategies
• Human-AI workflow description
• Post-market monitoring plan
• Predetermined Change Control Plan (PCCP) if the device will be updated post-market

The PCCP framework is particularly important for AI/ML-based IVDs. Because ML models can be improved through retraining, FDA wants manufacturers to describe — at the time of initial authorization — what types of changes they anticipate making to the algorithm, under what conditions, and what validation they will perform. This allows the device to evolve without requiring a new regulatory submission for each model update, as long as the changes fall within the pre-approved plan.

EU IVDR: Under the IVDR, AI/ML-based IVDs are treated as software IVDs and classified according to their intended purpose using the standard seven classification rules. The IVDR's General Safety and Performance Requirements (Annex I) include specific provisions for software-based devices, requiring validation of the algorithm, documentation of training data, and ongoing monitoring of performance.

The EU AI Act (Regulation (EU) 2024/1689) adds an additional layer of regulation for AI-based medical devices. Medical devices (including IVDs) that incorporate AI systems are classified as "high-risk AI systems" under Annex I of the AI Act, which imposes requirements for risk management, data governance, transparency, human oversight, and conformity assessment. However, the AI Act defers to the MDR/IVDR for conformity assessment procedures, meaning that for IVD manufacturers, IVDR conformity assessment through a Notified Body remains the primary pathway.

Specific Challenges for AI/ML IVDs

AI/ML-based IVDs present several unique regulatory and technical challenges:

Training data representativeness: The performance of an ML model depends entirely on the data it was trained on. If training data does not adequately represent the diversity of patient populations, specimen types, pre-analytical variables, and disease prevalence that the device will encounter in clinical use, the model may exhibit bias or degraded performance in underrepresented groups. Regulators expect documentation of training data demographics, inclusion/exclusion criteria, and analysis of performance across subpopulations.

Algorithm transparency and explainability: "Black box" models that cannot explain how they arrive at diagnostic outputs face increasing regulatory scrutiny. The FDA's draft guidance recommends describing the model architecture, key features, and the rationale for algorithmic decisions. In the EU, the AI Act's transparency requirements further reinforce this expectation.

Continuous learning and locked algorithms: A locked algorithm does not change after deployment — its performance is fixed. A continuously learning algorithm updates its model based on new data post-deployment. The regulatory approach differs significantly: locked algorithms can be validated once and monitored for drift, while continuously learning algorithms require a Predetermined Change Control Plan (PCCP) and ongoing validation infrastructure.

Performance monitoring: AI/ML IVDs may degrade over time as patient populations change, disease prevalence shifts, or pre-analytical variables evolve. Post-market monitoring must detect performance degradation and trigger appropriate corrective actions — model retraining, recalibration, or withdrawal from the market.

Practical tip: If your IVD incorporates AI/ML, plan for both IVD-specific regulatory requirements (analytical and clinical validation of the diagnostic output) and AI-specific requirements (model transparency, bias analysis, data governance, post-market monitoring). The regulatory frameworks are converging, but they are not yet fully harmonized. Build your regulatory strategy to address both layers from the start, rather than retrofitting AI compliance after the fact.

Quality Management for IVD Manufacturers

ISO 13485 as the Foundation

ISO 13485:2016 (Medical devices — Quality management systems — Requirements for regulatory purposes) is the internationally recognized standard for quality management in the medical device industry, including IVDs. Compliance with ISO 13485 is:

• Required under the IVDR for all IVD manufacturers seeking CE marking in the EU
• Aligned with the FDA's Quality System Regulation (21 CFR Part 820), which is transitioning to the Quality Management System Regulation (QMSR) — a direct incorporation of ISO 13485 into US regulations
• Required by most international regulatory authorities (Health Canada, TGA, PMDA, NMPA, ANVISA) either directly or through harmonized standards

IVD-Specific Quality Considerations

While ISO 13485 applies to all medical devices, IVD manufacturers face specific quality challenges that require additional attention:

Reagent manufacturing: IVDs often include biological reagents (antibodies, enzymes, nucleic acid probes) that are inherently variable. Quality systems must address raw material qualification, incoming inspection, reference material traceability, lot-to-lot consistency, stability monitoring, and cold chain management.

Calibration and traceability: Quantitative IVDs must demonstrate metrological traceability to higher-order reference materials and reference measurement procedures. ISO 17511 (Metrological traceability of values assigned to calibrators, trueness control materials, and human samples) is the key standard.

Lot release testing: Each manufactured lot of IVD reagents must undergo quality control testing before release to market. The extent of lot release testing depends on the risk class and the regulatory framework. For EU IVDR Class D devices, Notified Body batch verification may be required.

Software validation: IVDs with embedded software or that function as SaMD must validate software per IEC 62304 (Medical device software — Software life cycle processes).

Design controls: IVD design and development must follow design controls per ISO 13485 Clause 7.3, with particular attention to intended use definition (including specimen type, user environment, target population), analytical and clinical performance requirements, usability, and labeling.

Complaint handling and adverse event reporting: IVD manufacturers must establish processes for receiving, investigating, and evaluating complaints. Complaints involving incorrect test results that could have caused or contributed to patient harm must be evaluated for reportability under FDA MDR (21 CFR 803) and/or IVDR vigilance requirements. The threshold for reportability in IVDs often involves assessing whether a known or suspected malfunction could have led to a misdiagnosis, delayed diagnosis, or incorrect treatment decision.

Supplier management: IVD manufacturers frequently rely on complex supply chains involving raw material suppliers (biological reagents, chemical compounds, antibodies, primers, enzymes), contract manufacturers, calibrator and control material providers, and software development subcontractors. ISO 13485 Clause 7.4 requires documented processes for purchasing, supplier evaluation, and incoming inspection. For biological raw materials, supplier qualification is particularly critical because lot-to-lot variability in antibodies, enzymes, or nucleic acid probes can directly affect assay performance.

Stability Testing and Shelf Life Determination

Stability testing is a critical and often underestimated aspect of IVD development and manufacturing. Unlike many traditional medical devices that are composed of stable materials with predictable shelf lives, IVD reagents frequently contain biological components — antibodies, enzymes, nucleic acids, substrates — that degrade over time and are sensitive to temperature, humidity, light, and other environmental conditions. Establishing a scientifically justified shelf life is both a regulatory requirement and a commercial necessity.

Regulatory Requirements

Both the FDA and the IVDR require manufacturers to establish the stability and shelf life of IVD products:

• FDA: 21 CFR 809.10(b)(5) requires labeling to include storage instructions and expiration dating. The FDA expects stability data to support the claimed shelf life, including real-time stability studies under recommended storage conditions and, where applicable, accelerated stability studies. For 510(k) submissions, stability data is typically required as part of the analytical performance section.
• IVDR: Annex I, Section 9.3 requires that IVDs be designed and manufactured to maintain their performance during the intended shelf life under the storage and transport conditions specified by the manufacturer. The performance evaluation report must include stability data. Notified Bodies routinely review stability protocols and data during technical documentation assessment.

Types of Stability Studies

IVD manufacturers should conduct multiple types of stability studies:

• Real-time stability: The gold standard. Products are stored under the recommended conditions (e.g., 2-8C, room temperature, -20C) and tested at defined intervals (e.g., 0, 3, 6, 9, 12, 18, 24 months) to verify that performance characteristics remain within specification. The claimed shelf life must be supported by real-time data — accelerated studies alone are not sufficient.
• Accelerated stability: Products are stored under stressed conditions (elevated temperature, humidity) to predict long-term stability in a shorter timeframe. Accelerated studies are useful for early development decisions and for supporting initial regulatory submissions while real-time data accumulates, but they cannot replace real-time studies.
• In-use stability (open-vial stability): Determines how long a reagent remains stable after opening or after first use. This is particularly important for multi-use containers, reagent packs on automated analyzers, and calibrators/controls that are reconstituted before use.
• Shipping/transport stability: Verifies that the product maintains its performance characteristics during transport under expected conditions, including temperature excursions. This is critical for IVDs with cold chain requirements.

ISO 23640: The Key Standard

ISO 23640:2011 (In vitro diagnostic medical devices — Evaluation of stability of in vitro diagnostic reagents) provides the framework for designing and conducting IVD stability studies. Key principles include:

• Stability studies should use production-representative lots (not R&D lots)
• Performance characteristics tested during stability should include the most stability-sensitive parameters for the assay
• Acceptance criteria must be predefined and based on the product's performance specifications
• Statistical analysis should account for measurement variability and detect meaningful trends
• Study protocols should specify sample size, time points, storage conditions, and analytical methods

Practical tip: Begin real-time stability studies as early as possible — ideally as soon as you have production-representative material. Shelf life claims are one of the most common causes of regulatory delay because real-time data simply takes time to generate. If your target shelf life is 18 months, you need at least 18 months of real-time data. Plan accordingly and consider starting stability studies in parallel with analytical validation.

Building a QMS for an IVD Startup

If you are an early-stage company developing your first IVD, you do not need a fully mature QMS on day one. A phased approach is practical:

Phase 1 — Design and development: Implement document control, design controls (design inputs, outputs, verification, validation, transfer), and risk management (ISO 14971). These processes are essential during product development and must be in place before you generate regulatory submission data.

Phase 2 — Regulatory submission preparation: Add supplier management (qualifying critical raw material suppliers), training management (documenting that personnel performing validation studies are trained), and CAPA processes (capturing and correcting issues identified during validation).

Phase 3 — Manufacturing and launch: Implement production and process controls, incoming inspection, in-process testing, lot release procedures, equipment calibration, environmental monitoring (if applicable), complaint handling, and medical device reporting.

Phase 4 — Post-market: Implement post-market surveillance processes, customer feedback analysis, trend reporting, and periodic performance evaluation updates (for IVDR compliance).

Key point: Even with a phased approach, design controls and risk management must be in place from the beginning. If you conduct design and validation activities without proper design controls, you may need to repeat that work to satisfy regulatory reviewers or Notified Body auditors.

Key IVD Standards

Beyond ISO 13485, IVD manufacturers should be familiar with the following standards:

Standard	Title	Relevance
ISO 15189:2022	Medical laboratories — Requirements for quality and competence	Applies to clinical laboratories performing IVD testing; relevant for IVD manufacturers that also operate as testing laboratories, and for understanding the laboratory environment in which IVDs are used
ISO 20916:2019	In vitro diagnostic medical devices — Clinical performance studies using specimens from human subjects — Good study practice	Provides the framework for planning and conducting clinical performance studies; referenced by MDCG guidance and expected by Notified Bodies
EN 13612:2002	Performance evaluation of in vitro diagnostic medical devices	Guidance on external performance evaluation studies; superseded in many aspects by ISO 20916 but still referenced
ISO 17511:2020	In vitro diagnostic medical devices — Requirements for establishing metrological traceability of values assigned to calibrators, trueness control materials and human samples	Essential for quantitative IVDs; establishes the traceability chain from clinical measurement to reference materials
IEC 62304:2006+A1:2015	Medical device software — Software life cycle processes	Applies to IVDs with software components or SaMD IVDs
ISO 14971:2019	Medical devices — Application of risk management to medical devices	Risk management standard applicable to all IVDs
ISO 23640:2011	In vitro diagnostic medical devices — Evaluation of stability of in vitro diagnostic reagents	Stability testing framework for IVD reagents
ISO 18113 series	In vitro diagnostic medical devices — Information supplied by the manufacturer (labelling)	IVD-specific labeling requirements

Post-Market Surveillance for IVDs

Post-market surveillance (PMS) is the systematic process of monitoring the safety, performance, and quality of IVDs after they are placed on the market. Both the FDA and the IVDR require robust PMS programs, but the structure and deliverables differ.

FDA Post-Market Requirements

• Medical Device Reporting (MDR) — 21 CFR Part 803 requires manufacturers to report deaths, serious injuries, and malfunctions to the FDA. For IVDs, reportable events typically involve test failures that led to incorrect patient management (e.g., a false negative HIV test that resulted in delayed treatment).
• Corrections and removals — 21 CFR Part 806 requires reporting of recalls and field corrections.
• Post-market studies — The FDA may require post-market studies (522 studies) as a condition of approval, particularly for PMA devices.
• Annual reports — PMA holders must submit annual reports summarizing post-market data.

IVDR Post-Market Requirements

The IVDR establishes a comprehensive PMS framework with different deliverables depending on device class:

Deliverable	Class A	Class B	Class C	Class D
PMS Plan	Required	Required	Required	Required
PMS Report (PMSR)	Required	Required	—	—
Periodic Safety Update Report (PSUR)	—	—	Required	Required
Performance Evaluation Report (PER) update	Regular schedule	Regular schedule	At least annually	At least annually
Post-Market Performance Follow-Up (PMPF)	May be justified not to	May be justified not to	Typically required	Typically required

Post-Market Performance Follow-Up (PMPF) is the IVD equivalent of Post-Market Clinical Follow-up (PMCF) for medical devices under the MDR. The PMPF is a proactive, planned process to collect and evaluate performance data after the device is on the market. It may involve:

• Prospective collection of real-world performance data
• Analysis of field complaints and vigilance reports
• Review of published literature on the analyte, clinical condition, or competing technologies
• Comparison of device performance with state-of-the-art alternatives
• Targeted studies to address specific safety or performance questions

For Class C and D devices, the PMPF is generally expected. For Class A and B devices, the manufacturer must justify in writing any decision not to conduct PMPF.

Vigilance reporting: The IVDR requires manufacturers to report serious incidents and field safety corrective actions (FSCAs) through the EUDAMED vigilance module (when operational) and to the relevant competent authority. Trend reporting is also required — manufacturers must report statistically significant increases in the frequency or severity of non-serious incidents or expected undesirable side effects.

For IVDs specifically, a "serious incident" can include situations where the device provided incorrect results that led to — or could have led to — death, serious deterioration in health, or serious public health threat. This includes false negative results for life-threatening conditions (e.g., missed HIV infection in blood screening), false positive results that led to unnecessary invasive procedures, and systematic performance degradation affecting multiple lots or instruments.

FDA vs. IVDR Post-Market Comparison

Aspect	FDA	IVDR
Adverse event reporting	MDR reports (deaths, serious injuries, malfunctions) within 30 days (or 5 days for emergencies)	Serious incident reports within 15 days (or 2 days for serious public health threats)
Trend reporting	Not formally required (but FDA may request trend data)	Required — statistically significant increases in frequency/severity
Periodic reports	Annual reports for PMA devices	PSUR for Class C/D (annually for Class C, as requested for Class D)
Proactive data collection	Post-market studies (522 orders, voluntary registries)	PMPF required for Class C/D; justified exception for Class A/B
Database	MAUDE (voluntary/mandatory reporting)	EUDAMED vigilance module (becoming mandatory May 2026)

Key MDCG Guidance Documents for IVDs

The European Commission's Medical Device Coordination Group (MDCG) has published several guidance documents that are essential reading for IVD manufacturers navigating the IVDR:

Document	Title	Why It Matters
MDCG 2020-16 Rev.3	Guidance on Classification Rules for in vitro Diagnostic Medical Devices under Regulation (EU) 2017/746	Detailed interpretation of the seven classification rules with worked examples
MDCG 2022-2	Guidance on general principles of clinical evidence for In Vitro Diagnostic medical devices (IVDs)	Framework for generating and documenting clinical evidence across all risk classes
MDCG 2022-3	Verification of manufactured class D IVDs by notified bodies	Guidance on batch verification requirements for Class D devices
MDCG 2022-19	Performance study application/notification documents under Regulation (EU) 2017/746	Templates and requirements for clinical performance study submissions
MDCG 2023-1	Guidance on the health institution exemption under Article 5(5) of Regulation (EU) 2017/746	Requirements for in-house IVDs manufactured by health institutions
MDCG 2022-10	Q&A on transitional provisions under the IVDR	Clarification on transition timelines, legacy devices, and sell-through dates

These guidance documents do not have the force of law, but they represent the agreed interpretation of the IVDR by EU member state competent authorities. Notified Bodies and competent authorities use them as the basis for their conformity assessments and market surveillance activities. Manufacturers should treat them as de facto requirements.

International IVD Regulations

IVD regulation outside the US and EU varies significantly in maturity, structure, and requirements. This section provides an overview of the key international markets.

Japan (PMDA / MHLW)

Japan regulates IVDs under the Pharmaceuticals and Medical Devices Act (PMD Act). The Pharmaceuticals and Medical Devices Agency (PMDA) conducts product reviews, while the Ministry of Health, Labour and Welfare (MHLW) issues marketing approvals.

• Classification: IVDs are classified into four risk classes (I-IV), similar to the Japanese medical device classification. Class I = general IVDs (notification only); Class II = IVDs requiring special controls; Class III = higher-risk IVDs; Class IV = highest-risk IVDs (e.g., blood screening)
• Pathway: Class I devices require notification (todokede); Class II require third-party certification (ninsho) by a Registered Certification Body or PMDA review (shonin); Class III and IV require PMDA marketing approval (shonin)
• Quality system: MHLW Ministerial Ordinance No. 169 (QMS Ordinance), aligned with ISO 13485. QMS audits are conducted as part of the marketing approval process
• Clinical data: Japan may accept foreign clinical data but often requires supplementary data from Japanese specimens or Japanese clinical sites. This is particularly common for molecular diagnostics and companion diagnostics, where analyte prevalence or genetic variant frequencies may differ between populations
• LDTs: Regulated separately under clinical laboratory regulations; LDTs in Japan are overseen by MHLW under laboratory accreditation frameworks rather than under the PMD Act
• Registration timeline: Typically 6-12 months for Class II ninsho; 12-24 months for Class III/IV shonin, depending on complexity and whether priority review applies

China (NMPA)

The National Medical Products Administration (NMPA) regulates IVDs in China under the Regulations on Supervision and Administration of Medical Devices (State Council Order No. 739, revised 2021) and the IVD-specific implementing rules, including the Administrative Measures for the Registration and Filing of IVD Reagents.

• Classification: Three classes (I, II, III), with Class I subject to filing (bei'an) and Class II/III requiring registration (zhuce)
• Pathway: Class I filing with local (municipal) authorities; Class II registration with provincial drug administrations; Class III registration with NMPA at the national level
• Quality system: Requirements align with ISO 13485, but NMPA's Quality Management System Specification for IVD Reagent Manufacturing (YY/T 0287) includes additional China-specific requirements. GMP inspections are conducted before first-time Class III registration
• Clinical data: Chinese clinical trial data generally required for Class III IVDs; exemptions available for certain product types listed in the Exemption Catalog, where international clinical data plus local analytical verification may be accepted. Clinical trials must be conducted at NMPA-approved clinical trial institutions
• Unique considerations: In-country testing requirements (type testing at NMPA-designated laboratories), mandatory Chinese-language labeling, authorized representative (registrant) requirement for foreign manufacturers, and product-specific technical guidance issued by NMPA for common IVD categories
• Timeline: Typically 12-18 months for Class II; 18-30+ months for Class III, including clinical trial conduct and review

Brazil (ANVISA)

Brazil's National Health Surveillance Agency (ANVISA) regulates IVDs under RDC 36/2015 (IVD products) and related resolutions.

• Classification: Four risk classes (I, II, III, IV). Class I = low risk (e.g., general reagents); Class II = moderate risk (e.g., clinical chemistry, hematology); Class III = high risk (e.g., immunoassays for infectious diseases, companion diagnostics); Class IV = highest risk (e.g., blood screening for HIV/HCV/HBV)
• Pathway: Class I requires notification (cadastro); Class II requires registration (registro); Class III and IV require registration with technical documentation review, including analytical and clinical performance data
• Quality system: GMP requirements per RDC 665/2022 (formerly RDC 16/2013); ISO 13485-based audits. Recent RDC 982/2025 introduces a risk-based approach to Good Manufacturing and Distribution Practices, streamlining approvals for companies with demonstrated quality records
• Clinical data: May accept international clinical data; Brazilian-specific data may be required for certain product types. ANVISA has been increasingly accepting clinical data from international multicenter studies that include Brazilian sites
• Good Distribution Practices: ANVISA enforces GDP requirements for the IVD supply chain, including cold chain validation for temperature-sensitive reagents
• INMETRO certification: Certain IVD instruments may require additional certification from the National Institute of Metrology, Standardization and Industrial Quality (INMETRO)

Australia (TGA)

The Therapeutic Goods Administration (TGA) regulates IVDs under the Therapeutic Goods Act 1989 and the Therapeutic Goods (Medical Devices) Regulations 2002.

• Classification: Four classes (1, 2, 3, 4) that map broadly to the IVDR classes (A, B, C, D). Class 1 = low risk; Class 2 = low-moderate risk; Class 3 = moderate-high risk; Class 4 = high risk (blood screening, transfusion-related)
• Pathway: Class 1 IVDs are included in the Australian Register of Therapeutic Goods (ARTG) through manufacturer self-assessment; Class 2-4 require conformity assessment, with increasing levels of evidence and TGA review
• Quality system: ISO 13485 certification required, typically demonstrated through an MDSAP audit or a TGA-recognized EU Notified Body certificate
• Mutual recognition: Australia accepts EU Notified Body certificates and CE marking as evidence in the conformity assessment process, though additional TGA-specific requirements apply (Essential Principles of safety and performance, Australian-specific labeling)
• UDI: TGA is implementing UDI requirements aligned with IMDRF guidance, with phased implementation beginning in 2025
• Sponsor obligations: Foreign manufacturers must appoint an Australian sponsor who is legally responsible for the device on the Australian market

South Korea (MFDS)

The Ministry of Food and Drug Safety (MFDS) regulates IVDs in South Korea under the Medical Devices Act.

• Classification: Four classes (I-IV). IVDs follow the same four-class system as other medical devices, with Class I being the lowest risk and Class IV the highest
• Pathway: Class I requires notification; Class II-IV require technical documentation review by MFDS or a recognized testing laboratory (KOLAS-accredited). Class III and IV devices undergo more extensive review including clinical performance data assessment
• Quality system: KGMP (Korean Good Manufacturing Practice), aligned with ISO 13485. GMP audits are required for Class II-IV devices prior to initial registration
• Clinical data: Korean clinical trial data may be required for high-risk IVDs; MFDS increasingly accepts international clinical data for certain product categories. Bridging studies using Korean clinical specimens may be required to demonstrate applicability to the Korean population
• Registration timeline: Typically 6-12 months for Class II; 12-18 months for Class III/IV
• UDI: South Korea has implemented a UDI system aligned with IMDRF principles, with phased implementation timelines by device class

Canada (Health Canada)

Health Canada regulates IVDs as a subset of medical devices under the Medical Devices Regulations (SOR/98-282), which fall under the Food and Drugs Act. IVDs in Canada are referred to as In Vitro Diagnostic Devices (IVDDs).

• Classification: Four classes (I, II, III, IV), with Class I being the lowest risk and Class IV being the highest. The classification of an IVDD is based on the device's intended use and the risk posed by incorrect results. Class I includes general laboratory instruments and specimen receptacles; Class II includes clinical chemistry analyzers and routine immunoassays; Class III includes tests for sexually transmitted infections, cancer markers, and genetic testing; Class IV includes blood screening tests for transfusion-transmitted infections (HIV, HCV, HBV) and blood grouping reagents
• Pathway: Class I devices do not require a Medical Device License (MDL) but may require a Medical Device Establishment License (MDEL) if sold directly to consumers. Class II devices require an MDL with a declaration of conformity. Class III and IV devices require an MDL with full premarket review, including analytical and clinical performance data assessment
• Quality system: ISO 13485 certification is required for all Class II-IV device manufacturers. Health Canada requires certification through the Medical Device Single Audit Program (MDSAP) — Canada was among the first countries to make MDSAP mandatory (since January 2019). An MDSAP audit conducted by an accredited auditing organization satisfies the quality system requirements
• Clinical data: Health Canada generally accepts clinical data generated outside Canada, provided the data is relevant to the Canadian population. For novel IVDs or those with unique intended uses, Canadian-specific clinical data may be requested. Health Canada participates in the IMDRF and may reference reviews conducted by other regulatory authorities (particularly the FDA) through regulatory reliance pathways
• LDTs: Laboratory developed tests in Canada are regulated under provincial jurisdiction (not federal). Provincial laboratory accreditation programs (e.g., the Institute for Quality Management in Healthcare in Ontario) oversee LDT quality, but there is no federal premarket review requirement for LDTs
• Registration timeline: Typically 15-30 business days for Class II; 75 business days (target) for Class III/IV, though actual timelines may vary
• UDI: Health Canada has implemented a Unique Device Identification system aligned with IMDRF principles, with phased compliance deadlines

India (CDSCO)

India regulates IVDs under the Medical Devices Rules, 2017 (as amended), administered by the Central Drugs Standard Control Organisation (CDSCO) under the Ministry of Health and Family Welfare. India's IVD regulatory framework has undergone significant modernization in recent years.

• Classification: Four classes (A, B, C, D), aligned with the IMDRF/GHTF classification framework. Class A = low risk (e.g., specimen collection containers, general laboratory reagents); Class B = low-moderate risk (e.g., clinical chemistry reagents, routine immunoassays); Class C = moderate-high risk (e.g., blood glucose self-monitoring, fertility tests, tests for sexually transmitted infections); Class D = high risk (e.g., blood grouping reagents, HIV/HCV/HBV screening tests, NAT for blood screening)
• Pathway: Class A and B devices require registration (notification) with CDSCO; Class C and D devices require import or manufacturing licenses with full premarket review. The Drugs Controller General of India (DCGI) approves Class C and D devices
• Quality system: Manufacturers must comply with the Medical Devices Rules quality management system requirements, which are broadly aligned with ISO 13485. Indian manufacturing sites are subject to GMP inspections by CDSCO. Foreign manufacturers must provide evidence of quality system compliance, which may include ISO 13485 certification
• Clinical data: Clinical investigation data from Indian sites may be required for higher-risk IVDs (Class C and D), particularly for novel devices or those with intended uses specific to disease profiles prevalent in the Indian population (e.g., tropical infections, specific genetic variants). India accepts international clinical data in many cases, particularly when supplemented by local analytical performance data
• Testing: IVDs may be subject to type testing at CDSCO-designated laboratories before registration. Performance evaluation requirements include analytical and clinical performance data appropriate to the device class
• In-country representative: Foreign manufacturers must appoint an authorized Indian agent who is responsible for regulatory compliance and serves as the point of contact with CDSCO
• Registration timeline: Typically 3-6 months for Class A/B; 6-12 months for Class C; 9-18 months for Class D, though timelines can vary significantly depending on the completeness of the submission and any queries from CDSCO

Singapore (HSA)

The Health Sciences Authority (HSA) regulates IVDs in Singapore under the Health Products Act and the Health Products (Medical Devices) Regulations.

• Classification: Four classes (A, B, C, D), aligned with the IMDRF/GHTF framework. Class A = lowest risk; Class B = low-moderate risk; Class C = moderate-high risk; Class D = highest risk. The classification criteria are similar to the IVDR and IMDRF guidance
• Pathway: Class A devices are exempt from product registration but require dealer's licensing. Class B, C, and D devices require product registration with HSA, with increasing documentation requirements at higher risk classes. Class D devices undergo the most rigorous premarket assessment
• Quality system: ISO 13485 certification is required. HSA accepts MDSAP audit reports and recognizes quality system certifications from recognized conformity assessment bodies
• Regulatory reliance: Singapore's HSA is a pioneer in regulatory reliance and work-sharing frameworks. HSA may reference reviews conducted by reference regulatory authorities — including the FDA, EU Notified Bodies, Health Canada, TGA, and PMDA — to expedite its own review process. This can significantly reduce registration timelines for devices that have already been cleared or approved in a reference jurisdiction
• ASEAN harmonization: Singapore participates in the ASEAN Medical Device Directive (AMDD) harmonization initiative, which aims to align medical device (including IVD) regulations across Southeast Asian nations. The ASEAN Common Submission Dossier Template (CSDT) can be used for regulatory submissions in multiple ASEAN member states
• Clinical data: HSA generally accepts international clinical data and does not routinely require Singapore-specific clinical studies. However, for novel IVDs or devices intended for conditions with different epidemiology in the Singapore population, local clinical performance data may be requested
• Registration timeline: Typically 3-6 months for Class B; 6-10 months for Class C/D, depending on the complexity and whether a reliance pathway is used

Harmonization Through IMDRF

The International Medical Device Regulators Forum (IMDRF) is driving regulatory convergence for IVDs through several key initiatives:

• GHTF/IMDRF guidance documents on IVD classification, performance evaluation, and quality management. The GHTF Study Group 1 document on IVD classification (SG1/N045:2008) provided the conceptual foundation for the IVDR's four-class, rule-based classification system. IMDRF guidance on SaMD (including SaMD IVDs) has been adopted by regulators worldwide.
• MDSAP (Medical Device Single Audit Program) — A single audit recognized by the US (FDA), Canada (Health Canada), Australia (TGA), Japan (PMDA/MHLW), and Brazil (ANVISA), reducing the audit burden for manufacturers selling into multiple markets. For IVD manufacturers, an MDSAP audit can satisfy quality system requirements in up to five jurisdictions simultaneously, dramatically reducing audit costs and scheduling complexity.
• UDI harmonization — IMDRF guidance on Unique Device Identification is being adopted (with variations) by regulators worldwide. The basic concept — a unique identifier on every IVD product that enables tracking through the supply chain — is converging across the US, EU, China, South Korea, and other markets, though implementation timelines and technical requirements still vary.
• Regulatory reliance and recognition — Several regulatory authorities are exploring or implementing reliance pathways that allow them to leverage reviews conducted by other regulators. For example, the Malaysian MDA and Chinese NMPA launched a joint reliance program in 2025 for IVD devices, enabling expedited market access based on reviews conducted in one jurisdiction. Singapore's HSA has similar reliance frameworks. These approaches reduce duplication and accelerate access for patients in markets with developing regulatory capacity.

For manufacturers targeting multiple international markets, a harmonized regulatory strategy built on ISO 13485, MDSAP, and IMDRF-aligned technical documentation can significantly reduce the cost and complexity of multi-market submissions. Design your master technical file to satisfy the most stringent requirements (typically IVDR), then adapt it for each additional market's specific requirements.

Regulatory Strategy: Bringing an IVD to Market

Navigating the IVD regulatory landscape requires strategic planning. Whether you are a startup developing your first diagnostic test or an established manufacturer expanding into new markets, the following framework can guide your approach.

Step 1: Define Intended Use Precisely

Everything flows from the intended use statement. For IVDs, the intended use must specify:

• What the device measures or detects (the analyte, marker, or condition)
• What clinical information the result provides (screening, diagnosis, monitoring, treatment selection)
• What specimen types are used (whole blood, serum, plasma, urine, saliva, swab, tissue)
• Who the intended user is (laboratory professional, healthcare professional at point of care, lay person/self-testing)
• What the target population is (age, sex, clinical context, risk factors)

A precisely defined intended use determines your classification, predicate landscape, validation study requirements, and labeling. An overly broad intended use increases regulatory burden. An overly narrow intended use limits your commercial opportunity. Find the right balance early.

Step 2: Determine Classification in Every Target Market

Classification is not universal. The same IVD may be Class II in the US, Class C in the EU, Class III in China, and Class 3 in Australia. Determine the classification in each target market before you design your validation studies, because you will need to satisfy the requirements of the most demanding jurisdiction.

Step 3: Identify Predicate Devices (FDA) and State of the Art (IVDR)

For the FDA 510(k) pathway, identify one or more predicate devices that share your intended use and technological characteristics. The predicate will anchor your substantial equivalence argument and define the performance benchmarks for your analytical and clinical validation studies.

For the IVDR, identify the state of the art for your device type — the established performance expectations based on existing products, clinical guidelines, Common Specifications (if applicable), and relevant standards. Your performance evaluation must demonstrate that your device meets or exceeds the state of the art.

Step 4: Design Validation Studies to Satisfy Multiple Jurisdictions

If you plan to market in both the US and the EU (and potentially other markets), design your validation studies to satisfy both the FDA's guidance-based requirements and the IVDR's three-pillar framework. In practice, this often means:

• Conducting analytical performance studies per CLSI standards (precision per EP05, method comparison per EP09, linearity per EP06, LoD per EP17, interference per EP07) — these satisfy both FDA and IVDR requirements
• Conducting a clinical performance study with sufficient sample size and population diversity to satisfy both FDA clinical agreement requirements and IVDR clinical performance expectations
• Documenting scientific validity through a structured literature review (IVDR Pillar 1)
• Planning for a CLIA waiver study (US) if the device is intended for point-of-care or self-testing use

Step 5: Engage with Regulators Early

Use the FDA Pre-Submission program to align on study design before conducting expensive validation studies. In the EU, engage a Notified Body early — especially given current capacity constraints. Consider requesting a pre-submission consultation if the Notified Body offers one.

Step 6: Build Your QMS to Support the Product Lifecycle

Your quality management system is not just a compliance checkbox — it is the operational infrastructure that ensures your device performs consistently throughout its lifecycle. Build it early, maintain it continuously, and ensure it covers design controls, supplier management, production controls, complaint handling, post-market surveillance, and CAPA.

Step 7: Plan for Post-Market from Day One

Post-market surveillance is not an afterthought — it is a continuous obligation that begins the day your device enters the market. Before launch, establish your PMS plan, define your complaint handling procedures, set up adverse event reporting workflows, and (for IVDR) prepare your PMPF plan. Identify the metrics you will track, the data sources you will monitor, and the thresholds that will trigger corrective action.

For IVDs, post-market surveillance has a unique dimension: you must monitor not only device-specific performance (lot-to-lot variability, field failures, customer complaints) but also the evolving scientific and clinical landscape. New clinical guidelines, emerging pathogens, changes in disease prevalence, new competitor technologies, and updated reference materials can all affect the clinical relevance and acceptability of your IVD. Your performance evaluation is a living document — it must be updated to reflect the current state of the art.

Frequently Asked Questions

What is the difference between an IVD and a medical device?

An IVD is a type of medical device. All IVDs are medical devices, but not all medical devices are IVDs. The distinguishing characteristic is that IVDs examine specimens taken from the human body (in vitro = outside the body), while other medical devices interact directly with the patient (in vivo). IVDs are often subject to separate or additional regulatory requirements because the nature of risk — incorrect test results rather than physical harm from device-body interaction — is fundamentally different.

Can software be an IVD?

Yes. Software that analyzes specimens or specimen data to provide diagnostic information is classified as an IVD. This includes software that interprets images from digital pathology, algorithms that analyze molecular sequencing data, and AI/ML models that identify patterns in multi-analyte panels. Software IVDs are also classified as Software as a Medical Device (SaMD) and must comply with both IVD-specific and software-specific regulatory requirements (e.g., IEC 62304).

What is the difference between FDA IVD classification and EU IVDR classification?

The FDA uses a three-class system (I, II, III) based on the level of regulatory control needed, with each device type assigned to a specific class via product codes. The IVDR uses a four-class system (A, B, C, D) based on seven classification rules that consider both individual patient risk and public health risk. The two systems do not map directly to each other — a Class II FDA device might be Class B, C, or even D under the IVDR depending on its intended purpose and the applicable classification rule.

What is a CLIA waiver and why does it matter for IVD manufacturers?

A CLIA waiver allows an IVD test to be performed in non-laboratory settings (physician offices, pharmacies, homes) without meeting the personnel, quality control, and proficiency testing requirements that apply to moderate and high complexity tests. For manufacturers, obtaining a CLIA waiver dramatically expands the addressable market. To obtain a waiver, the manufacturer must submit a CLIA waiver application to the FDA demonstrating that the test is simple and has an insignificant risk of erroneous results.

What happened to the FDA's LDT regulation?

In May 2024, the FDA published a final rule to phase out enforcement discretion for laboratory developed tests (LDTs). However, in March 2025, a federal court vacated the rule, holding that LDTs are not "devices" under the FD&C Act and that FDA exceeded its statutory authority. In September 2025, the FDA formally reverted its regulations to pre-2024 language. As of 2026, LDTs remain subject to CLIA oversight but are not subject to FDA premarket review or most device requirements. The regulatory future of LDTs remains uncertain and may require Congressional legislation.

What is the IVDR transition timeline?

The IVDR has been applicable since May 26, 2022, but extended transition periods apply to legacy devices: Class D devices must have applied to a Notified Body by May 2025 (sell-through until December 2027), Class C by May 2026 (sell-through until December 2028), and Class B / Class A sterile by May 2027 (sell-through until December 2029). New devices entering the EU market for the first time must fully comply with the IVDR immediately.

How are companion diagnostics regulated?

In the United States, companion diagnostics have historically been regulated as Class III devices requiring PMA. However, the FDA proposed reclassifying oncology nucleic acid-based companion diagnostics to Class II (510(k) pathway) in November 2025. In the EU, companion diagnostics are classified as Class C under the IVDR and require conformity assessment by a Notified Body, structured performance evaluation, and post-market performance follow-up.

What is the difference between analytical performance and clinical performance?

Analytical performance measures how well the device detects or measures the target analyte — accuracy, precision, sensitivity, specificity, limit of detection, linearity, and interference. Clinical performance measures how well the device's results correlate with actual clinical conditions in real patients — diagnostic sensitivity (true positive rate), diagnostic specificity (true negative rate), positive predictive value, and negative predictive value. Both are essential, but they answer different questions: analytical performance asks "Does the device measure the analyte correctly?" while clinical performance asks "Do the device's results accurately reflect the patient's clinical status?"

Do I need a Notified Body for my IVD in the EU?

Under the IVDR, all IVDs except Class A non-sterile devices require Notified Body involvement. This is a dramatic change from the IVDD, where approximately 80% of IVDs could be self-certified. If your IVD is Class B, C, or D, or if it is a Class A sterile device, you must engage a Notified Body for conformity assessment. Note that the number of Notified Bodies designated for the IVDR is limited, and capacity constraints remain a significant industry challenge.

What are the key post-market surveillance deliverables for IVDs under the IVDR?

All IVD classes require a post-market surveillance plan. Class A and B devices require a PMS Report (PMSR). Class C and D devices require a Periodic Safety Update Report (PSUR), which is more comprehensive than the PMSR and includes benefit-risk determination, PMPF findings, sales volume, and estimated user population data. The Performance Evaluation Report must be updated at least annually for Class C and D devices. Post-Market Performance Follow-Up (PMPF) is typically required for Class C and D devices and must be justified if not conducted for Class A and B devices.

How do I determine whether my product is an IVD or a general medical device?

The key question is whether the device examines specimens derived from the human body (in vitro) or interacts directly with the body (in vivo). If your product analyzes biological specimens — blood, urine, saliva, tissue, swabs — to provide diagnostic or monitoring information, it is an IVD. If it measures physiological parameters directly on or in the patient (e.g., a pulse oximeter, blood pressure monitor, or ECG), it is a general medical device. Some products fall in a gray area — for example, continuous glucose monitors that use an implanted sensor to measure interstitial glucose are regulated as general medical devices (not IVDs), even though they measure the same analyte (glucose) that blood glucose meters (IVDs) measure. The distinguishing factor is whether the measurement happens in vitro or in vivo.

What is the difference between a complementary diagnostic and a companion diagnostic?

A companion diagnostic provides information that is essential for the safe and effective use of a corresponding therapeutic product — the therapeutic's labeling requires use of the companion diagnostic. A complementary diagnostic provides information that aids in treatment decisions but is not essential — the therapeutic can be used safely and effectively without the diagnostic. For example, PD-L1 IHC assays used with certain immunotherapy drugs are considered complementary diagnostics: the drug may be used regardless of PD-L1 status, but PD-L1 results inform the expected benefit. The regulatory pathway and requirements may differ between companion and complementary diagnostics.

What are the main benefits of IVD testing compared to in vivo diagnostics?

IVDs offer several distinct advantages. They are generally non-invasive or minimally invasive (requiring only a specimen collection), can be performed on large numbers of samples simultaneously (high throughput), enable standardized and reproducible testing, can be decentralized to point-of-care or home settings, and allow quantitative measurement of specific biomarkers with high precision. IVDs also enable testing that is impossible in vivo — such as genetic sequencing, culture-based pathogen identification, and multi-analyte panels that test for dozens of conditions from a single specimen. In vivo diagnostics (imaging, physiological monitoring) provide complementary information that IVDs cannot — such as anatomical visualization, real-time hemodynamic monitoring, and spatial localization of disease.

What is EUDAMED and when does it become mandatory?

EUDAMED (European Database on Medical Devices) is the centralized IT system established by the IVDR for the registration, tracking, and transparency of medical devices and IVDs in the EU. It consists of six interconnected modules: actor registration, UDI/device registration, Notified Body and certificates, clinical performance studies, vigilance and post-market surveillance, and market surveillance. Following decision (EU) 2025/2371, four EUDAMED modules become mandatory on May 28, 2026. Devices placed on the market before that date must be registered in the UDI/Device module by November 28, 2026. EUDAMED will be publicly accessible, meaning that certain device information — including performance data summaries, safety information, and Notified Body certificates — will be available to the public, healthcare professionals, and other stakeholders.

How long does it take to bring an IVD to market?

Timeline varies significantly depending on the regulatory pathway, device classification, and target markets. For a Class II IVD in the US (510(k) pathway), the total development-to-clearance timeline is typically 18-36 months, including design and development (6-12 months), analytical and clinical validation (6-12 months), submission preparation and FDA review (6-9 months). For a PMA (Class III), add 12-24 months for clinical studies and 6-12 months for the more extensive review process. In the EU under the IVDR, timeline depends heavily on Notified Body availability — the conformity assessment process for a Class C device typically takes 9-18 months from Notified Body application to certificate issuance, after technical documentation is complete. For manufacturers targeting both the US and EU simultaneously, the overall timeline is typically 24-48 months from design freeze to first market authorization.

What is a Predetermined Change Control Plan (PCCP) for AI/ML IVDs?

A PCCP is a plan submitted as part of the initial regulatory authorization for an AI/ML-based IVD that describes the types of modifications the manufacturer anticipates making to the algorithm after it is on the market. The PCCP specifies the scope of anticipated changes (e.g., retraining the model with new data, adjusting decision thresholds), the methodology for validating those changes (e.g., performance testing protocols, acceptance criteria), and the triggers or conditions under which changes would be implemented. If a change falls within the scope of an FDA-approved PCCP, the manufacturer can implement it without submitting a new 510(k) or PMA supplement, provided the validation results meet the pre-specified criteria. This framework enables AI/ML IVDs to improve over time without the regulatory burden of a new submission for each model update.

Key Takeaways

1. IVDs are medical devices. Despite being analyzed outside the body, IVDs are regulated as medical devices in every major jurisdiction. The regulatory obligations — premarket review, quality system compliance, post-market surveillance — are real and enforceable.

2. Risk classification drives everything. Whether you are working within the FDA's three-class system or the IVDR's four-class system, your device's classification determines your premarket pathway, the level of evidence required, the regulatory costs, and the ongoing post-market obligations.

3. The IVDR transition is ongoing and consequential. If you sell IVDs in the EU, the transition deadlines are real: Class C Notified Body applications are due by May 2026, Class B by May 2027. EUDAMED modules become mandatory in May 2026. Failure to meet these deadlines means you cannot place your device on the EU market.

4. LDT regulation in the United States is unresolved. The FDA's 2024 final rule was vacated by a federal court and the agency has reverted to enforcement discretion. But the underlying policy debate continues. Manufacturers and laboratories should prepare for the possibility of future regulatory action, whether through FDA rulemaking or Congressional legislation.

5. Companion diagnostic pathways are shifting. The FDA's proposed reclassification of oncology CDx from Class III to Class II could dramatically reduce regulatory burden and accelerate patient access. Under the IVDR, companion diagnostics are Class C and require Notified Body assessment.

6. Performance evaluation is not optional. Whether you follow the FDA's guidance-based approach or the IVDR's three-pillar framework (scientific validity, analytical performance, clinical performance), you must generate rigorous evidence that your IVD works as intended. This evidence must be maintained and updated throughout the device lifecycle.

7. AI/ML adds regulatory complexity. AI-based IVDs face layered requirements: IVD-specific analytical and clinical validation, software lifecycle requirements (IEC 62304), AI-specific requirements (model transparency, bias analysis, PCCP), and — in the EU — the AI Act. Plan for all of these from the start.

8. CLIA categorization is separate from FDA clearance. In the United States, FDA premarket clearance and CLIA complexity categorization are independent determinations. For maximum market access, plan for both.

9. Post-market surveillance is a continuous obligation. Both the FDA and the IVDR require ongoing monitoring of safety and performance. Under the IVDR, the deliverables — PMSR, PSUR, PER updates, PMPF — are structurally defined and timeline-driven.

10. Think globally from the start. IVD regulatory requirements vary significantly across jurisdictions. If you plan to market in multiple countries, design your quality system, clinical evidence strategy, and technical documentation to satisfy the most stringent requirements first (typically IVDR), then adapt for other markets. Leverage MDSAP where available to reduce audit burden.

11. Companion diagnostics are evolving rapidly. The FDA's proposed reclassification of oncology CDx to Class II and the IVDR's structured classification of CDx as Class C reflect a maturing regulatory landscape for precision medicine. If you develop companion diagnostics, stay current with both FDA and EU regulatory developments, and plan your co-development strategy with the therapeutic manufacturer early.

12. International harmonization is progressing but incomplete. IMDRF guidance, MDSAP audits, and regulatory reliance frameworks are reducing the duplication burden for multi-market IVD manufacturers, but significant jurisdiction-specific requirements remain — particularly around clinical data, labeling language, and local testing requirements. A well-designed master technical file and a harmonized quality system are your best tools for navigating multi-market complexity efficiently.

The IVD regulatory landscape is dynamic. Regulations evolve, transition deadlines approach, classification schemes shift, and new guidance documents reshape expectations. The manufacturers that succeed are those who treat regulatory intelligence as a core competency — staying current, engaging with regulators proactively, and building quality systems that can adapt to change. This guide provides the foundation; keeping up with the changes is an ongoing responsibility.