FDA Medical Device Classification: Product Codes, Device Classes, and Regulatory Pathways

Why Classification Is the First Question You Must Answer

Every regulatory decision you make for a medical device sold in the United States flows from a single determination: how the FDA classifies your device. Classification dictates your premarket pathway (510(k), De Novo, PMA, or exempt), the quality system requirements you must satisfy, the labeling rules that apply, the post-market obligations you carry, and the user fees you will pay. Get classification wrong and you risk months of wasted work, a Refuse to Accept letter, or — worse — marketing a device illegally.

This is not a theoretical exercise. The FDA's Center for Devices and Radiological Health (CDRH) and Center for Biologics Evaluation and Research (CBER) regulate over 190,000 devices across more than 6,000 product codes. The classification system is the organizational backbone of all of it. Whether you are a startup bringing your first device to market or a multinational managing hundreds of product lines, classification is where your regulatory strategy begins.

The FDA Classification Framework

Legal Foundation

The Medical Device Amendments of 1976 established the three-tier classification system that remains in effect today. Every medical device legally marketed in the United States is assigned to one of three regulatory classes — Class I, Class II, or Class III — based on the level of control necessary to provide a reasonable assurance of the device's safety and effectiveness. This framework is codified in Sections 513 through 515 of the Federal Food, Drug, and Cosmetic Act (FD&C Act) and implemented through Title 21 of the Code of Federal Regulations (21 CFR Parts 862–892).

The underlying principle is risk-based. Devices that pose the least risk to patients require the least regulatory control. Devices that pose the greatest risk — those that sustain life, are implanted, or present a potential unreasonable risk of illness or injury — require the most.

Class I: General Controls

Class I devices are considered low risk. They are subject only to "general controls," which are the baseline requirements that apply to all medical devices regardless of class:

• Establishment registration (21 CFR Part 807) — Manufacturers, importers, and specification developers must register their establishments with the FDA annually.
• Device listing (21 CFR Part 807) — All commercially distributed devices must be listed with the FDA.
• Good Manufacturing Practice / Quality System (21 CFR Part 820, transitioning to QMSR) — Compliance with current Good Manufacturing Practice requirements. Most Class I devices are exempt from design controls but must comply with the remaining quality system requirements.
• Labeling (21 CFR Part 801) — Devices must be properly labeled with the manufacturer name and address, adequate directions for use, and any required warnings.
• Medical Device Reporting (21 CFR Part 803) — Manufacturers must report deaths, serious injuries, and malfunctions to the FDA.
• Premarket notification — Most Class I devices are exempt from 510(k) requirements, but not all.

Examples of Class I devices: Elastic bandages, examination gloves, tongue depressors, manual stethoscopes, bedpans, arm slings, mercury thermometers, manual surgical instruments (scalpels, forceps, retractors), dental floss, and ice bags.

Approximately 47% of all medical device types are classified as Class I. Of those, roughly 95% are exempt from the 510(k) premarket notification requirement.

Class II: General Controls + Special Controls

Class II devices are moderate-risk devices for which general controls alone are insufficient to provide reasonable assurance of safety and effectiveness. These devices require "special controls" in addition to general controls. Special controls can include:

• Performance standards — FDA-recognized consensus standards or FDA-specific performance criteria
• Post-market surveillance requirements — Specific post-market data collection obligations
• Patient registries — Participation in device registries to track long-term outcomes
• FDA guidance documents — Device-specific guidance that functions as de facto special controls
• Special labeling requirements — Warnings, contraindications, or specific use instructions beyond standard labeling

Examples of Class II devices: Powered wheelchairs, infusion pumps, surgical drapes, pregnancy test kits, acupuncture needles, powered surgical instruments, contact lenses, blood pressure monitors, pulse oximeters, syringes, catheters (most types), surgical mesh, and the majority of AI/ML-enabled software as a medical device (SaMD).

Approximately 43% of all medical device types fall into Class II. The 510(k) premarket notification is the standard pathway for Class II devices, though some Class II device types are exempt from 510(k).

Class III: General Controls + Premarket Approval

Class III devices are the highest-risk category. These are devices that sustain or support life, are implanted, or present a potential unreasonable risk of illness or injury. General controls and special controls are insufficient to provide reasonable assurance of safety and effectiveness, so these devices require premarket approval (PMA) — the most stringent type of FDA premarket review.

PMA requires clinical evidence demonstrating the device's safety and effectiveness. This typically involves one or more clinical trials, extensive bench and animal testing, and a level of documentation far beyond what a 510(k) requires.

Examples of Class III devices: Replacement heart valves, coronary stents, implantable pacemakers and defibrillators, silicone breast implants, cochlear implants, implantable cerebellar stimulators, high-frequency ventilators, and certain diagnostic tests for high-risk conditions (e.g., HIV blood donor screening tests).

Approximately 10% of all medical device types are classified as Class III.

Classification Summary Table

Characteristic	Class I	Class II	Class III
Risk level	Low	Moderate	High
Regulatory controls	General controls	General controls + special controls	General controls + PMA
Typical premarket pathway	Exempt (most) or 510(k)	510(k) (most) or exempt	PMA
Design controls required?	Exempt for most	Yes	Yes
Clinical data typically required?	Rarely	Sometimes	Almost always
Percentage of device types	~47%	~43%	~10%
Examples	Tongue depressors, bandages, manual instruments	Infusion pumps, pulse oximeters, pregnancy tests	Heart valves, pacemakers, breast implants
User fee (FY2026, standard)	$0 (if exempt) / $26,067 (if 510(k) required)	$26,067 (510(k))	$579,272 (PMA)

How Classification Determines Your Regulatory Pathway

Classification and regulatory pathway are tightly linked, but they are not the same thing. Classification describes the risk tier. The regulatory pathway describes how you get to market. Here is how they connect:

Device Classification	Primary Pathway	Alternative Pathways
Class I, exempt	No premarket submission required	N/A
Class I, not exempt	510(k)	N/A
Class II, exempt	No premarket submission required	N/A
Class II, not exempt	510(k)	De Novo (if no predicate exists)
Class III, with existing PMA regulation	PMA	PMA supplement, Humanitarian Device Exemption (HDE)
Class III, pre-amendment (no PMA called)	510(k) (rare)	PMA if FDA calls for it
Novel device, no classification	De Novo (most common for novel low/moderate-risk)	PMA (if high-risk), 510(k) (if predicate can be identified)

The De Novo Pathway and Classification

The De Novo pathway deserves special attention in the context of classification because a successful De Novo does not just clear a single device — it creates a new classification regulation. The device that goes through De Novo is classified into Class I or Class II with the appropriate general and special controls, a new product code is assigned, and a new 21 CFR regulation number is established. All subsequent devices of the same type can then use the De Novo device as a predicate for 510(k) clearance.

This is why De Novo is not merely an alternative pathway — it is a classification pathway. If your device is truly novel and no predicate exists, De Novo is how you establish the regulatory framework for your device category.

The FDA has processed an increasing number of De Novo requests in recent years, driven largely by digital health devices, AI/ML-enabled SaMD, and novel combination products that do not fit neatly into existing product codes.

Pre-Amendment Devices and the 510(k) Exception for Class III

A nuance that catches many people: not all Class III devices require a PMA. Some Class III device types are "pre-amendment" — they were on the market before the 1976 Amendments and the FDA has not yet called for PMA applications (under Section 515(b) of the FD&C Act). These devices can be marketed through a 510(k), which is a significantly lower bar than PMA.

However, the FDA has been working through the backlog of these pre-amendment Class III devices for decades. When the FDA issues a final order calling for PMAs for a device type, manufacturers of those devices must submit a PMA within the specified timeframe or remove their devices from the market. This is called a "PMA call" or "515(b) order." The number of Class III devices that can still go through 510(k) is shrinking.

Product Codes and Regulation Numbers

What Is a Product Code?

A product code is a three-letter alphanumeric identifier assigned by the FDA to each recognized medical device type. Every classified device maps to a product code. The product code is your Rosetta Stone for navigating the FDA regulatory system — it links your device to its:

• Device class (I, II, or III)
• Regulation number (the specific 21 CFR section)
• Review panel (one of 16 medical specialty panels)
• Submission type (510(k), PMA, De Novo, exempt)
• 510(k) exemption status
• Special controls (for Class II devices)
• GMP exemption status
• Third-party review eligibility

Examples of product codes:

Product Code	Device	Class	Regulation Number	Panel
DXN	Orthopedic bone screw	II	888.3040	Orthopedic
QKQ	Pulse oximeter	II	870.2700	Cardiovascular
FRN	Clinical electronic thermometer	II	880.2910	General Hospital
LLZ	Automated external defibrillator	III	870.5310	Cardiovascular
OZO	Electrode, electroencephalographic	II	882.1400	Neurological
QAS	Software, radiological CAD	II	892.2080	Radiology
MNH	Spinal pedicle screw system	II	888.3080	Orthopedic
JJX	Pregnancy test kit (home use)	II	866.5940	Immunology
DQY	Dental implant	II	872.3640	Dental
NFT	Continuous glucose monitor	II	862.1355	Clinical Chemistry

What Is a Regulation Number?

The regulation number (also called the classification regulation number) is the specific section of 21 CFR that describes the device type, its intended use, and its classification. The format follows the pattern 8XX.XXXX, where the first three digits identify the medical specialty panel and the digits after the decimal point identify the specific device type.

For example, 21 CFR 870.2700 describes pulse oximeters:

• 870 = Cardiovascular Devices (Part 870)
• 2700 = the specific regulation for pulse oximeters

The regulation text typically includes:

• A description of what the device is and what it is intended for
• Identification of the device's classification (Class I, II, or III)
• For Class II devices, a reference to any special controls that apply
• For Class I and II devices, whether the device is exempt from 510(k) and/or GMP requirements

The 16 Medical Specialty Panels

The FDA organizes medical devices into 16 medical specialty panels, each corresponding to a Part of 21 CFR. These panels originated from the advisory committees that recommended classifications for devices when the 1976 Amendments were implemented.

Panel	21 CFR Part	Examples
Anesthesiology	868	Ventilators, anesthesia machines, CO2 monitors
Cardiovascular	870	Heart valves, stents, pacemakers, ECG monitors
Clinical Chemistry	862	Blood glucose meters, clinical chemistry analyzers
Dental	872	Dental implants, orthodontic brackets, dental cements
Ear, Nose, and Throat	874	Hearing aids, cochlear implants, nasal splints
Gastroenterology and Urology	876	Endoscopes, urological catheters, lithotripters
General and Plastic Surgery	878	Surgical mesh, sutures, wound closure strips
General Hospital	880	Hospital beds, examination gloves, patient scales
Hematology	864	Blood cell counters, coagulation analyzers
Immunology	866	Pregnancy tests, allergy test kits, blood typing reagents
Microbiology	866	Culture media, sensitivity discs, staining kits
Neurological	882	EEG electrodes, neurostimulators, cranial electrotherapy stimulators
Obstetrical and Gynecological	884	Fetal monitors, intrauterine devices, cervical dilators
Ophthalmic	886	Contact lenses, intraocular lenses, retinoscopes
Orthopedic	888	Hip prostheses, bone screws, spinal fixation devices
Pathology	864	Tissue processors, microtomes, embedding media
Physical Medicine	890	Powered wheelchairs, ultrasonic diathermy, CPM devices
Radiology	892	X-ray systems, MRI machines, ultrasound imaging systems, radiological CAD software

Note: The numbering has some overlap — Hematology and Pathology share Part 864, and Immunology and Microbiology share Part 866 — because the original panel structure predated the CFR organization. In practice, you navigate by product code rather than panel number.

How to Use the FDA Product Classification Database

The FDA Product Classification Database is the definitive tool for determining your device's classification. It is publicly available at accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm. Knowing how to use it effectively is a core regulatory skill.

Step-by-Step Search Strategy

Step 1 — Start with a keyword search. Enter a descriptive term for your device in the "Device" field. Use a broad, generic term rather than a trade name or marketing name. For example, search "oximeter" rather than "Masimo Rad-97" or "fingertip SpO2 sensor."

Step 2 — Review the results carefully. The database returns every product code whose device description matches your keyword. Pay attention to:

• Device name — Read the full description, not just the short name
• Product code — The three-letter identifier
• Device class — I, II, III, or U (unclassified)
• Regulation number — The 21 CFR section
• Submission type — Tells you the premarket pathway (510(k), PMA, De Novo, exempt, etc.)

Step 3 — Click into the product code detail page. Each product code page provides critical information:

• Full device description
• The regulation number and a link to the CFR text
• Whether the device is exempt from 510(k)
• Whether the device is exempt from GMP
• The review panel
• Any applicable special controls (for Class II)
• Third-party review eligibility
• Summary of Safety and Effectiveness Data (SSED) links for PMA devices
• Total Product Life Cycle (TPLC) report link — Clicking the TPLC link for a product code takes you to a consolidated report showing every 510(k), PMA, De Novo, and HDE submission ever associated with that product code. This is one of the most powerful research tools in the FDA system and is frequently overlooked.
• Implanted device and life-sustaining/life-supporting flags — These flags indicate whether the device type is considered an implant or a life-sustaining/supporting device, which affects post-market reporting obligations and recall classification
• Summary Malfunction Reporting (SMR) eligibility — Indicates whether the device type is eligible for the Summary Malfunction Reporting program under 21 CFR Part 803

Step 4 — Read the regulation text. Click through to the actual CFR text to understand exactly what the classification regulation covers. This is essential because many product codes have very specific intended use descriptions, and your device may or may not fit within the scope of that regulation.

Step 5 — Cross-reference with the 510(k) database. Once you have identified candidate product codes, search the 510(k) Premarket Notification database to see what other devices have been cleared under those codes. This confirms whether your device type aligns with the product code and helps you identify potential predicates.

Step 6 — Use the TPLC report to see the full regulatory history. From the product code detail page, click the "TPLC Product Code Report" link. This report aggregates all premarket submissions (510(k), PMA, De Novo, HDE), all recall events, all adverse event reports, and all compliance actions associated with that product code. Reviewing the TPLC report gives you a complete picture of how the FDA and industry have interacted with this device type over time — including which companies have received clearance, what predicates they used, and whether the device type has a history of recalls or safety signals.

Worked Example: Searching for a Pulse Oximeter

To make the database search process concrete, here is a complete walkthrough for classifying a pulse oximeter.

1. Open the database. Navigate to accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm.

2. Enter a keyword search. Type "oximeter" in the "Device" field and click "Search."

3. Review the results. The database returns multiple product codes related to oximetry. The key results include:

Product Code	Device Name	Class	Regulation Number	Submission Type
DPZ	Oximeter	II	870.2700	510(k)
OLK	Pulse oximeter for over-the-counter use	II	870.2700	510(k)
QKQ	Pulse oximeter	II	870.2700	510(k)
MUD	Ear oximeter	II	870.2710	510(k)
NKF	Oximeter, fetal	II	884.2640	510(k)
QCE	Cutaneous oxygen monitor	II	870.2750	510(k)

4. Note the differences. Even though these all relate to oximetry, they have different product codes because they serve different intended uses. Product code DPZ is the general oximeter, QKQ is specifically for pulse oximeters, OLK is for over-the-counter pulse oximeters, and NKF is for fetal oximeters (classified under the Obstetrical panel at 884.2640 rather than the Cardiovascular panel at 870.2700). Choosing the wrong product code could send your submission to the wrong review division.

5. Click into QKQ (pulse oximeter). The product code detail page reveals:

• Device Class: 2
• Regulation Number: 870.2700
• Submission Type: 510(k)
• Review Panel: Cardiovascular
• GMP Exempt?: No
• Implanted Device?: No
• Life-Sustain/Support Device?: No
• Third Party Review: Not Third Party Eligible
• Summary Malfunction Reporting: Ineligible
• Recognized Consensus Standards: Lists applicable standards (e.g., ISO 80601-2-61 for pulse oximetry)
• Special Controls / Guidance: Links to the applicable guidance documents

6. Cross-reference. Click the TPLC Product Code Report link for QKQ to see all devices cleared under this code. You will find hundreds of cleared 510(k) devices, which confirms this is an active product code with a robust predicate history. Search the 510(k) database for recent clearances under QKQ to identify potential predicate devices.

7. Read the regulation text. Navigate to 21 CFR 870.2700 to confirm the regulation's scope covers your device's intended use.

This entire process — from search to classification confirmation — typically takes 30 to 60 minutes for a well-characterized device type. For novel or boundary devices, expect to spend significantly more time and potentially involve FDA directly through a Pre-Sub or 513(g).

Using Advanced Search Filters

The Product Classification Database offers several search filters beyond the basic keyword search that many users overlook:

• Review Panel dropdown — Narrow results to a specific medical specialty (e.g., Cardiovascular, Orthopedic). This is useful when a keyword returns too many results across unrelated panels.
• Submission Type dropdown — Filter by 510(k), PMA, 510(k) Exempt, HDE, Contact ODE, Enforcement Discretion, or EUA. Use this to quickly identify all exempt device types in a panel, or all PMA device types.
• Device Class dropdown — Filter by Unclassified, Class I, Class II, Class III, HDE, or Not Classified. Use this to see all Class III device types in a specific panel.
• Implanted Device and Life-Sustain/Support Device flags — Filter for only implantable or life-sustaining devices. This is relevant for understanding post-market obligations, which are more stringent for these device types.
• Third Party Eligible filter — Identify device types eligible for review by FDA-accredited third-party review organizations, which can significantly reduce 510(k) review timelines.
• Summary Malfunction Reporting filter — Identify devices eligible (or ineligible) for the SMR program.
• Product Code direct search — If you already know the three-letter product code (e.g., from a competitor's 510(k) summary), enter it directly in the "Product Code" field for an instant lookup.
• Regulation Number direct search — Enter a regulation number (e.g., 870.2700) to see all product codes classified under that regulation. This is critical because a single regulation number often maps to multiple product codes with different intended uses, submission requirements, or exemption statuses.

Practical tip: When researching a device type, always search by regulation number to see the full universe of product codes under that regulation. There are more than 6,500 product codes mapped to approximately 1,700 regulation numbers in the database. Some regulation numbers have more than 50 associated product codes, each with subtly different intended uses, and selecting the wrong one can misdirect your entire regulatory strategy.

Common Search Mistakes

• Searching by brand name — The database catalogs generic device types, not commercial products. Searching "Apple Watch" returns nothing. Searching "electrocardiograph" returns the relevant product codes.
• Being too specific — Searching "wireless Bluetooth-enabled digital blood pressure cuff with smartphone app integration" returns nothing. Searching "sphygmomanometer" returns DXN and related codes.
• Being too broad — Searching "surgical" returns hundreds of product codes. Narrow it down. "Surgical laser" is better than "surgical."
• Confusing product codes with regulation numbers — The product code is a three-letter code (e.g., QKQ). The regulation number is a CFR section (e.g., 870.2700). They are linked but distinct.
• Assuming one product code per device — Some devices, particularly combination products or multi-function devices, may be described by more than one product code. You need to determine which code best represents the primary intended use.

Product Code Lookup Strategy for Novel or Complex Devices

When your device does not map cleanly to an existing product code, use this escalating strategy:

1. Search by function. What does your device do clinically? Search for that function.
2. Search by anatomy. What part of the body does your device interact with? Search by body system.
3. Search by similar devices. What existing device is most similar to yours? Search for that device type.
4. Review cleared/approved devices from competitors. Search the 510(k) and PMA databases for competitors' devices and note which product codes they used.
5. Check De Novo authorizations. If your device is truly novel, look at the De Novo database (accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMN/denovo.cfm) for recently authorized devices with similar technology or intended use.
6. Submit a Pre-Submission (Pre-Sub). If you still cannot determine the correct product code, include the classification question in a formal Pre-Submission to the FDA. The review division will tell you which product code applies — or whether your device requires a De Novo.
7. Request a 513(g) classification determination. This is the formal mechanism for obtaining an FDA classification determination (discussed in detail below).

510(k) Exempt vs. Non-Exempt Devices

The 510(k) exemption status of a device is determined by its product code. When Congress or the FDA determines that a device type poses sufficiently low risk, it can be exempted from the 510(k) requirement. Exemption means you can legally market the device without submitting a premarket notification — but you must still comply with all other applicable requirements (establishment registration, device listing, labeling, MDR reporting, and quality system requirements unless also GMP-exempt).

Class I Exemptions

The vast majority of Class I devices are exempt from 510(k). Of the approximately 780 Class I device types, roughly 740 are exempt. The remaining Class I device types that require a 510(k) tend to be those with specific safety concerns — for example, certain surgical instruments that pose infection risk or devices that contact internal tissues.

Class II Exemptions

A smaller number of Class II devices are also 510(k) exempt. The FDA has exempted certain Class II device types when it determined that premarket review is unnecessary to provide reasonable assurance of safety and effectiveness — for instance, certain dental devices, powered exercise equipment, and AC-powered adjustable hospital beds.

Limitations on Exemptions

Even exempt devices lose their exemption if any of the following apply:

• The device has a new intended use that differs from the intended use described in the classification regulation
• The device operates using a different fundamental scientific technology than the classified device type
• The device is for a use that is of substantial importance in preventing impairment of human health, and presents a potential unreasonable risk of illness or injury

If any of these conditions apply, a premarket submission is required even for otherwise exempt device types. This catches manufacturers who assume their novel technology is exempt simply because it falls under an exempt product code — if the technology is fundamentally different from what the exemption contemplated, the exemption does not apply.

How to Check Exemption Status

For any product code, the Product Classification Database entry explicitly states the device's 510(k) exemption status. Look for the "Submission Type" field:

Submission Type Value	Meaning
510(k) Exempt	No premarket notification required (subject to limitations above)
510(k)	510(k) submission required
PMA	Premarket Approval required
De Novo	De Novo classification request expected
HDE	Humanitarian Device Exemption pathway

Practical tip: Even if a device type is listed as 510(k) exempt, document your exemption determination in your Design History File or regulatory file. If the FDA inspects your facility, you need to demonstrate that you evaluated the exemption criteria and confirmed they apply to your specific device.

De Novo Classification in Depth

When De Novo Is the Right Pathway

The De Novo classification pathway (Section 513(f)(2) of the FD&C Act) is designed for novel devices that are low-to-moderate risk but have no predicate device. Before the De Novo pathway was streamlined by the FDA Reauthorization Act of 2017 (FDARA), novel devices without predicates were automatically classified into Class III — even if they were clearly low risk. The De Novo pathway corrects this by allowing manufacturers to request classification directly into Class I or Class II with appropriate controls.

You should consider De Novo when:

• Your device has no legally marketed predicate device
• Your device is not high-risk (it would not require PMA-level evidence)
• You want to establish a new classification that future devices can reference as predicates

De Novo vs. 510(k)

Factor	510(k)	De Novo
Predicate required?	Yes	No
Creates new classification?	No	Yes (new product code, regulation number, special controls)
Standard of review	Substantial equivalence	Reasonable assurance of safety and effectiveness
Risk level	Class I (non-exempt) or Class II	Novel Class I or Class II
Review timeline	~3–5 months	~5–12 months
User fee (FY2026)	$26,067 (standard)	$173,782 (standard)
Outcome	Clearance (SE determination)	Authorization (De Novo grant + new classification)

What the FDA Expects in a De Novo Request

A De Novo submission is more involved than a 510(k) because you are not merely demonstrating equivalence to an existing device — you are proposing the entire regulatory framework for a new device type. Your submission must include:

• Device description and intended use — What the device is, how it works, and what clinical need it addresses
• Risk analysis — Identification of all risks associated with the device, proposed mitigations, and the rationale for why the device is Class I or Class II (not Class III)
• Proposed classification — Your recommended class (I or II) and the general and special controls you believe are appropriate
• Non-clinical testing data — Bench testing, biocompatibility, electrical safety, software verification and validation, and other performance data
• Clinical evidence — Clinical data may or may not be required depending on the device. The FDA will evaluate whether non-clinical data alone provides reasonable assurance of safety and effectiveness.
• Labeling — Proposed labeling, including any specific warnings or use instructions you believe should be part of the special controls
• Proposed special controls (for Class II) — These become binding on all future manufacturers of devices in this classification

Practical tip: If you are pursuing De Novo, a Pre-Submission meeting with the FDA is not optional — it is essential. Use the Pre-Sub to align on the proposed special controls, testing requirements, and whether clinical data will be necessary. Proceeding without this alignment significantly increases the risk of a lengthy review with multiple rounds of additional information requests.

Requesting a Classification Determination: Section 513(g)

What Is a 513(g) Request?

Section 513(g) of the FD&C Act allows any person to submit a written request to the FDA for information about the classification and regulatory requirements for a device. This is the formal mechanism for obtaining a classification determination when you are unsure which product code applies to your device or whether your device is even subject to regulation as a medical device.

When to Use 513(g)

• You have a new or modified device and cannot determine the correct product code
• Your device sits on the boundary between two product codes
• You are unsure whether your product is regulated as a medical device at all (e.g., wellness products, general fitness devices, clinical decision support software)
• You want a written FDA response that you can rely on for your regulatory strategy

What to Include in a 513(g) Request

A 513(g) request should include:

1. Device description — Detailed description of the device, its principles of operation, and its physical characteristics
2. Intended use — The specific clinical or medical purpose
3. Indications for use — The disease or condition the device is intended to diagnose, treat, monitor, or prevent, and the target patient population
4. Technological characteristics — Materials, energy sources, software, and any novel technology
5. Comparison to existing classified devices — If you have identified candidate product codes, explain how your device compares to the device description in those classification regulations
6. Any relevant promotional materials or labeling — These help the FDA understand how the device will be positioned in the market

Submission Format and User Fees

A 513(g) request must be accompanied by the applicable MDUFA user fee before the FDA will begin its review. For FY2026, the fees are:

Fee Type	Amount
Standard 513(g) fee	$7,820
Small business 513(g) fee	$3,910 (50% of standard)

The FDA recommends submitting 513(g) requests as an eCopy or using the voluntary electronic Submission Template and Resource (eSTAR) for 513(g)s. While eCopy is not legally required for 513(g) submissions (unlike 510(k) and De Novo submissions where electronic format is mandatory), using eCopy or eSTAR ensures faster routing and reduces processing delays. Alternatively, one complete paper copy may be submitted.

The submission should include the CDRH Premarket Review Submission Cover Sheet (Form FDA 3514) for eCopy submissions to facilitate correct routing to the appropriate review division. For products regulated by CBER, submissions should be submitted electronically through the FDA Electronic Submission Gateway or via the CBER submission email inbox.

The Informal Alternative: Device Determination Email

Before committing to a formal 513(g) submission with its associated user fee, consider the FDA's informal device determination pathway. The Division of Industry and Consumer Education (DICE) accepts email inquiries at DICE@fda.hhs.gov and DeviceDetermination@fda.hhs.gov for simple classification questions. You can also call DICE at 1-800-638-2041 or 301-796-7100 (live agents available 9:00 AM to 12:30 PM and 1:00 PM to 4:30 PM ET).

The informal email response is typically provided within 7 business days for straightforward inquiries. The response will provide a preliminary determination of whether the product is a medical device and, if so, the likely classification. However, the informal response explicitly states that it is not a classification decision and does not constitute FDA clearance or approval. If your question is complex, or if you need a response you can formally rely on for your regulatory strategy, the FDA may recommend submitting a formal 513(g) request.

What to Expect from a 513(g) Response

The FDA targets a 60-day response time for 513(g) requests, though actual turnaround times frequently exceed this target. The response will identify the applicable product code, device class, and regulatory pathway. However, 513(g) responses are advisory — they represent the FDA's position but are not binding in the same way as a clearance or approval.

The FDA's review process for a 513(g) follows a defined internal workflow:

1. Receipt and triage — The submission is received via CDRH's Document Control Center (DCC), which checks for user fee payment and eCopy compliance.
2. Assignment — The submission is assigned to a lead reviewer in the appropriate review division based on the device type.
3. Review and recommendation — The lead reviewer evaluates the device description, intended use, and technological characteristics, comparing them against existing classifications, regulations, and precedent set by similar devices.
4. Management concurrence — Senior management reviews the lead reviewer's recommendation before the response letter is finalized.
5. Response letter issuance — The letter specifies whether the product is a medical device, and if so, provides the device determination, classification (product code and class), and the type of premarket submission required.

Practical tip: Build your project timeline assuming the 513(g) response may take 3 to 4 months rather than the nominal 60 days. If you have not received a response after 60 days, a polite follow-up inquiry to the assigned review division is appropriate. Some regulatory professionals use a Pre-Submission (Pre-Sub) instead of a 513(g) to get classification guidance, since a Pre-Sub also allows you to discuss testing strategy, predicate selection, and other submission-specific questions in the same interaction. If your only question is classification, 513(g) is appropriate. If you have broader questions about your regulatory strategy, a Pre-Sub is more efficient.

513(g) vs. Pre-Submission: Which to Use

Factor	513(g)	Pre-Submission (Pre-Sub)
Purpose	Classification determination only	Classification, testing strategy, predicate selection, clinical study design, labeling, and any other regulatory question
User fee (FY2026)	$7,820 (standard) / $3,910 (small business)	No user fee
Format	Written submission with device description	Written submission with specific questions; followed by a teleconference or in-person meeting with the review team
Response format	Written letter	Written feedback letter, followed by a meeting
Timeline	60-day target (often longer)	70–90 days from submission to meeting
Binding?	Advisory (non-binding)	Advisory (non-binding), but documented meeting minutes provide strong precedent
Best for	Simple classification questions; "is this a medical device?" determinations; product code identification	Complex devices; novel technologies; questions about testing requirements; De Novo strategy; situations requiring back-and-forth discussion

Classification by Risk: How the FDA Thinks About It

The FDA's classification decisions are driven by a risk-benefit analysis that considers several factors:

Risk Factors the FDA Evaluates

Factor	Lower Risk (Toward Class I)	Higher Risk (Toward Class III)
Duration of contact	Transient or brief contact	Permanent implant
Invasiveness	Non-invasive or surface contact	Surgically implanted
Body system	Non-critical (skin, musculoskeletal)	Central nervous system, cardiovascular
Energy delivered	Passive or low energy	High energy (electrical stimulation, radiation, thermal)
Dependence	Patient does not depend on device for survival	Life-sustaining or life-supporting
Local vs. systemic effect	Local, limited effect	Systemic effect or affects vital organs
User	Healthcare professional with training	Lay user (home use, OTC) can increase risk if device is complex
Existing safety history	Long, well-established safety track record	No safety history or history of adverse events
Technology maturity	Well-understood technology, consensus standards exist	Novel technology, no standards

The "Reasonable Assurance" Standard

For all classifications, the FDA asks: what level of regulatory control is necessary to provide a "reasonable assurance of safety and effectiveness"? This is not zero risk — all medical devices carry some risk. The question is whether the controls applied to a given class adequately mitigate the risks specific to that device type.

For Class I, general controls (registration, listing, labeling, GMP, MDR reporting) are sufficient.

For Class II, general controls alone are insufficient, but special controls — guidance documents, performance standards, post-market surveillance, special labeling — fill the gap.

For Class III, neither general nor special controls are sufficient. Only a full premarket evaluation of the device's safety and effectiveness data provides reasonable assurance.

The 16 Medical Specialty Panels: Classification Examples by Panel

To make the classification system concrete, here are examples of devices at each class level within selected medical specialty panels:

Panel	Class I Example	Class II Example	Class III Example
Anesthesiology	Tracheobronchial suction catheter	Electroanesthesia apparatus	High-frequency ventilator (certain types)
Cardiovascular	Electrode cable	Pulse oximeter	Replacement heart valve
Clinical Chemistry	Urinary pH test strip	Blood glucose test system	Blood gas analyzer (pre-amendment, some PMA required)
Dental	Dental hand instrument	Dental implant abutment	Endosseous dental implant (certain types)
ENT	Ear nose and throat manual instrument	Hearing aid	Cochlear implant
Gastroenterology/Urology	Enema kit	Urological catheter	Penile inflatable implant
General/Plastic Surgery	Nonabsorbable gauze	Surgical mesh (certain types)	Absorbable adhesion barrier
General Hospital	Bedpan	Infusion pump	None commonly (most move to other panels)
Immunology	Blood grouping reagent	Pregnancy test kit (home use)	HIV blood donor screening test
Neurological	Neurological examination instrument	EEG electrode	Implantable cerebellar stimulator
Obstetrical/Gynecological	Gynecological manual instrument	Electronic fetal monitor	Intrauterine device (copper, hormonal)
Ophthalmic	Eye pad	Daily-wear contact lens	Intraocular lens
Orthopedic	Cast component	Pedicle screw system	Total hip replacement system (certain types)
Physical Medicine	Exercise component	Powered wheelchair	Bone growth stimulator (certain types)
Radiology	X-ray film illuminator	Diagnostic ultrasound system	PET scanner (pre-amendment PMA)

Reclassification: How Device Classes Change Over Time

Device classifications are not permanent. The FDA can reclassify devices when new evidence demonstrates that a different level of control is more appropriate. Reclassification can move a device up or down the classification hierarchy.

Reclassification Mechanisms

Mechanism	Direction	How It Works
De Novo	Class III to Class I or II	Novel device without predicate is classified into appropriate risk class (effectively a "down-classification" from automatic Class III)
FDA-initiated reclassification (515(b))	Class III to Class II (or I)	FDA issues a proposed order to reclassify a Class III device type based on accumulated evidence that PMA-level controls are no longer necessary
Petition-based reclassification (513(e))	Any direction	Any person can petition the FDA to reclassify a device type. Requires submission of valid scientific evidence.
PMA call (515(b) order)	Effective Class II to III	FDA calls for PMA submissions for pre-amendment Class III devices that had been marketed via 510(k). Not technically a reclassification, but the practical effect is increased regulatory burden.

Reclassification by the Numbers (2013-2025)

Since the enactment of the FDA Safety and Innovation Act (FDASIA) in 2012, the FDA has published detailed annual reclassification data. From 2013 through 2025, the FDA reclassified a total of approximately 43 device types. The majority of these moved from a higher class to a lower class (typically Class III to Class II), reflecting accumulating evidence that less stringent controls can provide reasonable assurance of safety and effectiveness.

Year	Devices Reclassified	Direction (Majority)	Notable Examples
2013	2	Down (III to II)	Prosthetic cervical discs
2014	3	Down (III to II)	Wound dressing with drug component
2015	2	Down (III to II)	Gastrointestinal devices
2016	12	Down (III to II)	Peak year; multiple IVDs and surgical devices reclassified
2017	3	Down (III to II)	Transcutaneous electrical nerve stimulators
2018	2	Down (III to II)	Certain dental devices
2019	2	Down (III to II)	Orthopedic devices
2020	2	Down (III to II)	Certain ophthalmic devices
2021	8	Down (III to II)	Multiple IVDs including certain immunology tests
2022	0	N/A	No reclassifications finalized (OTC hearing aid rule was a new classification, not a reclassification)
2023	0	N/A	No reclassifications finalized
2024	2	Down (III to II)	Cytomegalovirus nucleic acid tests (product code PAB); ultrasound cyclodestructive device (product code LZR)
2025	4+	Down (III to II)	Hepatitis B antigen assays (product code LOM); Hepatitis B antibody assays (product code SEI); Hepatitis B nucleic acid-based assays; oncology companion diagnostic nucleic acid tests (proposed)

Recent and Pending Reclassification Orders (2024-2026)

Hepatitis B Virus (HBV) Assays (Final order, effective October 20, 2025) — The FDA reclassified qualitative HBV antigen assays, HBV antibody assays, and quantitative HBV nucleic acid-based assays from Class III (PMA) to Class II with special controls, subject to 510(k) premarket notification. This covered three product codes (LOM, SEI, and related codes) and is part of the FDA's broader initiative to down-classify most high-risk IVDs.

Nucleic Acid-Based Test Systems for Oncology Therapeutics (Proposed order, comments closed January 2026) — The FDA proposed reclassifying certain companion diagnostic nucleic acid-based test systems from Class III (PMA) to Class II (510(k) with special controls). This is significant because companion diagnostics have historically been one of the most prominent Class III IVD categories.

CDRH IVD Reclassification Initiative (Ongoing) — In January 2024, CDRH Director Jeff Shuren announced the Center's intent to initiate reclassification for most high-risk IVDs currently in Class III, particularly infectious disease and companion diagnostic IVDs. The rationale is that special controls can now be developed, alongside general controls, to provide reasonable assurance of safety and effectiveness for most of these test types, making PMA-level review unnecessary. This initiative is expected to affect dozens of product codes over the coming years and represents one of the largest reclassification efforts in FDA history.

Accessories Distinct Classification Initiative (December 2025) — The FDA issued a request for public comment on existing medical device accessories that may be suitable for distinct classification into Class I. This initiative recognizes that many accessories currently classified alongside their parent devices (often in Class II or III) may warrant their own lower-risk classification. The comment period was extended through March 2026. If finalized, this could reclassify numerous accessory device types into Class I with 510(k) exemption, reducing regulatory burden for accessory manufacturers.

Notable Reclassification Examples

• Automated external defibrillators (AEDs): Originally Class III (PMA required). The FDA reclassified AEDs for use in certain settings from Class III to Class II with special controls, dramatically increasing access to these life-saving devices. The product code LLZ was reclassified under a De Novo authorization for newer AED technologies.
• Metal-on-metal hip replacement systems: After serious adverse event data emerged (adverse local tissue reactions, elevated metal ion levels), the FDA issued orders requiring higher levels of evidence and post-market surveillance. Certain metal-on-metal hip systems were effectively reclassified to require PMA.
• Hearing aids (OTC): In 2022, the FDA finalized a rule creating a new category of over-the-counter hearing aids classified as Class II with several new product codes (QDD for self-fitting OTC hearing aids, QUH for OTC hearing aids with wireless technology, QUG for preset-based OTC hearing aids with wireless technology, QUF for preset-based OTC hearing aids without wireless technology), enabling consumers to purchase hearing aids without a prescription or professional fitting. This was one of the most significant classification actions in recent history, affecting an entirely new product category and creating multiple distinct product codes under 21 CFR 874.3305 and 874.3325.
• Clinical electronic thermometers: Originally required 510(k), certain electronic thermometer types have been reclassified or exempted from premarket notification requirements over time as the technology became well-understood and the safety history became extensive.
• Software as a Medical Device (SaMD): The FDA has been actively classifying AI/ML-enabled software through De Novo, creating new Class II product codes with tailored special controls. Each De Novo authorization for a new SaMD type effectively establishes a classification for that device category. As of late 2025, the FDA has authorized over 1,000 AI/ML-enabled devices cumulatively, with radiology imaging devices accounting for approximately 76% of all authorizations.

Practical tip: Reclassification activity is tracked in the Federal Register and on the FDA's Reclassification page, which maintains annual tables of all devices reclassified since 2013. If you manufacture a device type that is under consideration for reclassification, monitor the Federal Register and participate in the public comment period. Reclassification can significantly affect your regulatory obligations and competitive landscape.

Combination Products and Lead Agency Determination

What Is a Combination Product?

A combination product is a product composed of two or more regulated components — a drug and a device, a biologic and a device, a drug and a biologic, or all three — that are physically, chemically, or otherwise combined or mixed, or that are packaged together, or that are separately packaged but intended for use together where the investigational plan or proposed labeling indicates that both are required.

Examples include drug-eluting stents (device + drug), prefilled syringes (device + drug), antimicrobial wound dressings (device + drug), and cell therapy products delivered via a device scaffold (biologic + device).

How Combination Products Are Classified

Combination products are not classified in the traditional Class I/II/III sense. Instead, the FDA determines a "primary mode of action" (PMOA) which establishes which FDA center has lead jurisdiction:

Primary Mode of Action	Lead Center	Examples
Device	CDRH (Center for Devices and Radiological Health)	Drug-eluting stent (device provides structural support, drug prevents restenosis)
Drug	CDER (Center for Drug Evaluation and Research)	Prefilled autoinjector (drug is the primary therapy, device is delivery mechanism)
Biologic	CBER (Center for Biologics Evaluation and Research)	Cell-seeded scaffold (biologic is the therapy, device is the carrier)

Combination Product Examples in Detail

Understanding how the PMOA determination works in practice requires looking at specific product types:

Combination Product	Device Component	Drug/Biologic Component	PMOA	Lead Center	Regulatory Pathway
Drug-eluting coronary stent	Metallic stent scaffold	Antiproliferative drug (e.g., everolimus)	Device (structural support is primary)	CDRH	PMA
Prefilled autoinjector (e.g., epinephrine)	Spring-loaded injection device	Drug (epinephrine)	Drug (drug is the primary therapy)	CDER	NDA
Antimicrobial wound dressing	Wound dressing substrate	Antimicrobial agent (e.g., silver, PHMB)	Device (barrier/wound protection is primary)	CDRH	510(k) with special controls
Drug-coated balloon catheter	Balloon catheter	Antiproliferative drug coating	Device (mechanical dilation is primary)	CDRH	PMA
Bone graft with growth factor	Scaffold/carrier matrix	Recombinant human bone morphogenetic protein	Biologic (growth factor drives bone formation)	CBER	BLA
Transdermal patch	Adhesive patch delivery system	Drug (e.g., fentanyl, nicotine)	Drug (systemic drug delivery is primary)	CDER	NDA
Antibiotic bone cement	PMMA bone cement	Antibiotic (e.g., gentamicin, tobramycin)	Device (structural fixation is primary)	CDRH	510(k) or PMA depending on claims

Pre-Request for Designation (Pre-RFD)

Before committing to a formal RFD, manufacturers can submit a Pre-Request for Designation (Pre-RFD) to the Office of Combination Products (OCP) for informal, non-binding feedback on the regulatory identity or classification of their product. The Pre-RFD is particularly useful during early development when classification uncertainty could affect fundamental design decisions or funding strategy.

The Pre-RFD process follows a defined workflow:

1. Sponsor initiates Pre-RFD — Submit a clear, concise written document to OCP (combination@fda.gov) describing the product, all modes of action, and your recommended PMOA with supporting rationale.
2. OCP reviews for completeness — OCP checks the submission for required information. If incomplete, OCP sends a detailed gap assessment and the sponsor must resubmit.
3. OCP distributes to Centers — OCP sends the submission to the relevant FDA Centers (CDRH, CDER, CBER) for their assessment and checks for potential legal questions.
4. Centers complete assessment — Each relevant Center reviews the product and returns its assessment to OCP.
5. OCP aligns and responds — OCP reviews all Center assessments, holds follow-up discussions as needed, and issues a preliminary, non-binding written response to the sponsor.

The Pre-RFD has no user fee and no fixed statutory timeline, but OCP generally responds within 60 to 90 days. The feedback is non-binding, but it provides early directional guidance that can prevent costly missteps in product development.

Request for Designation (RFD)

If you are unsure which center should regulate your combination product, you can submit a Request for Designation (RFD) to the FDA's Office of Combination Products (OCP). The OCP is required to respond within 60 days with a binding determination of the lead center and the regulatory pathway.

The RFD is not a classification request — it is a jurisdictional determination. Once the lead center is identified, that center's classification framework applies. For device-led combination products, the standard Class I/II/III classification and corresponding pathways (510(k), De Novo, PMA) apply, with additional requirements for the drug or biologic component.

An RFD submission should include:

1. Product description — Detailed description of the product, all constituent parts, and how they are combined
2. Modes of action — Description of all modes of action and your recommended PMOA with supporting rationale
3. Proposed classification — Your recommendation for product classification (drug, device, biologic, or combination product)
4. Proposed lead center — Your recommendation for the lead center and the basis for that recommendation
5. Known products — Any similar products and their regulatory history
6. Claims and labeling — Proposed claims and labeling for the product

The RFD determination is binding — once OCP issues its designation, the assigned lead center manages the product's review. This is a critical distinction from the non-binding Pre-RFD and 513(g) responses.

The PMOA Algorithm

When the primary mode of action is not clear-cut — for instance, when a combination product has two modes of action of approximately equal therapeutic importance — OCP may use a secondary algorithm to determine the lead center. This algorithm considers:

1. Which Center has the most expertise with similar combination products
2. Which Center is best equipped to address the most significant safety and efficacy questions raised by the product
3. The existing regulatory history of similar products

This algorithmic approach ensures that combination products are reviewed by the Center with the greatest relevant expertise, even when the PMOA is ambiguous.

Quality System Requirements for Combination Products (21 CFR Part 4)

Combination products are subject to 21 CFR Part 4, which establishes Current Good Manufacturing Practice (cGMP) requirements specific to combination products. The key principle is that a combination product's manufacturer must comply with the cGMP requirements applicable to each constituent part:

• Device-led combination products: Must comply with 21 CFR Part 820 (Quality System Regulation / QMSR) for the device component, plus applicable drug GMP (21 CFR Parts 210/211) or biologic GMP (21 CFR Part 600 series) requirements for the non-device constituent part.
• Drug-led combination products: Must comply with 21 CFR Parts 210/211 for the drug component, plus applicable device QSR requirements for the device constituent part.
• Biologic-led combination products: Must comply with 21 CFR Part 600 series for the biologic component, plus applicable device QSR requirements for the device constituent part.

21 CFR Part 4 provides a "streamlined" approach that avoids requiring full compliance with multiple overlapping quality systems. Instead, it requires compliance with the lead center's primary quality system, supplemented by specific requirements from the contributing center's quality system that address constituent-part-specific concerns.

Intercenter Agreements

CDRH, CDER, and CBER have intercenter agreements that define how they share review responsibilities for combination products. The lead center manages the primary review, but the contributing center provides input on its component. For example, a drug-eluting stent reviewed by CDRH would still involve CDER review of the drug component (elution kinetics, drug safety, bioavailability).

Classification of Novel Devices

The Challenge

The FDA's classification system was built around device types that existed in 1976 or that have been classified since then through De Novo or reclassification. When a truly novel device emerges — one that does not fit any existing product code — the manufacturer faces a classification gap.

Decision Tree for Novel Devices

1. Search the Product Classification Database exhaustively. Use multiple search terms and strategies. Many devices that appear novel actually fall within an existing product code when you look at the underlying function rather than the marketing positioning.

2. Check the De Novo database. The FDA has created hundreds of new product codes through De Novo in recent years, particularly for digital health, AI/ML, and novel surgical technologies. Your "novel" device may already have a classification.

3. Review FDA guidance documents. The FDA has published guidance on several emerging technology areas that address classification:

   • Clinical Decision Support Software — Guidance clarifying which CDS functions are and are not regulated as devices
   • AI/ML-Based SaMD — Guidance addressing classification and the predetermined change control plan framework
   • Digital Health Technologies — Broad guidance addressing mobile apps, wearables, and remote monitoring
   • Breakthrough Devices Program — Not a classification pathway, but a program that facilitates review for novel devices that provide more effective treatment or diagnosis of life-threatening or irreversibly debilitating conditions

4. Use Pre-Submission or 513(g). If none of the above resolves your classification question, engage the FDA directly. A Pre-Submission meeting is the gold standard for novel devices.

5. Consider De Novo. If the FDA confirms no existing product code applies and your device is not high-risk, De Novo is almost certainly your pathway. Prepare for the additional time and cost relative to 510(k).

Breakthrough Device Designation and Classification

The Breakthrough Devices Program does not change a device's classification, but it provides several advantages for novel devices:

• Priority review and more interactive communication with the FDA
• Opportunities for pre-submission feedback, including on classification questions
• Data development plans that can include post-market data collection in lieu of pre-market studies
• Eligibility consideration for expedited access pathways

A device with Breakthrough designation still goes through the standard pathway (De Novo, 510(k), or PMA) — it just receives enhanced FDA engagement throughout the process.

In Vitro Diagnostic (IVD) Classification Under FDA

IVD-Specific Classification Considerations

In vitro diagnostic devices (IVDs) — tests and instruments used to diagnose diseases or conditions from samples taken from the human body — follow the same general Class I/II/III framework as other medical devices, but they have unique classification considerations.

IVD Classification Factors

The FDA considers several IVD-specific factors when classifying diagnostic tests:

Factor	Lower Risk	Higher Risk
Clinical decision	Screening, wellness, trending	Definitive diagnosis, treatment selection
Condition severity	Non-life-threatening, easily monitored	Life-threatening, irreversible conditions
Consequences of incorrect result	Minimal (further testing would catch error)	Severe (wrong treatment, missed critical diagnosis)
Availability of confirmatory testing	Readily available confirmatory tests exist	No confirmatory test, or result directly drives treatment
User	Laboratory professional (CLIA moderate/high complexity)	Home user (OTC/DTC)
Novelty of analyte/biomarker	Well-established analyte with extensive clinical validation	Novel biomarker with limited clinical evidence

IVD Classification Examples

IVD Type	Class	Rationale
Urine test strips (glucose, pH)	I	Simple, non-critical, confirmatory testing available
Home pregnancy test	II	Moderate risk, well-established technology, significant clinical decision but confirmatory testing available
Blood glucose meter (home use)	II	Moderate risk, drives insulin dosing but self-monitoring with clinical oversight
HbA1c test system	II	Monitoring test, does not drive acute treatment decisions alone
HIV screening test (blood banks)	III	High consequence of false negative (contaminated blood supply), no practical confirmatory step before transfusion
Companion diagnostic (CDx)	III (typically)	Drives treatment selection for serious conditions (e.g., which cancer therapy to administer)
Next-generation sequencing oncology panel	III (PMA or De Novo)	Drives treatment decisions for cancer, novel technology, complex analytical and clinical validation
COVID-19 home test (OTC)	II (De Novo)	Home use, pandemic context, special controls including performance requirements

Laboratory Developed Tests (LDTs)

A significant area of ongoing regulatory evolution is the FDA's approach to laboratory developed tests — IVDs designed, manufactured, and used within a single clinical laboratory. Historically, the FDA exercised enforcement discretion over LDTs, meaning they were not subject to premarket review even if they would otherwise require it. The FDA finalized a rule in 2024 to phase out this enforcement discretion and bring LDTs under the standard device classification framework, with a phased implementation timeline. This is one of the most significant shifts in IVD regulation in decades and will affect thousands of tests that were previously unregulated.

Manufacturers and laboratories developing LDTs should monitor the implementation timeline closely, as existing LDTs will need to comply with classification-appropriate requirements (registration, listing, adverse event reporting, and eventually premarket review) on a staggered schedule.

How FDA Classification Differs from EU MDR/IVDR Classification

Understanding how the US and EU classification systems differ is essential for manufacturers marketing devices in both regions.

Structural Differences

Feature	FDA (US)	EU MDR / IVDR
Number of classes	3 (Class I, II, III)	4 for devices (Class I, IIa, IIb, III); 4 for IVDs (Class A, B, C, D)
Classification method	Product code database (each device type individually classified by regulation)	Classification rules (22 rules for MDR, 7 rules for IVDR) applied to each device based on its characteristics
Who classifies	FDA assigns classification through regulation or De Novo	Manufacturer self-classifies by applying rules in Annex VIII (MDR) or Annex VIII (IVDR); Notified Body reviews
Granularity	Over 6,000 product codes with specific classifications	Rule-based system without product-code-level granularity
Software classification	Case-by-case, product code based (many SaMD classified through De Novo)	Rule 11 (MDR) — software classified based on clinical decision significance; can range from Class I to Class III
IVD classification	Same Class I/II/III framework as devices	Separate classification under IVDR with Classes A, B, C, D
Reclassification	FDA-initiated or petition-based, changes the regulation	MDCG guidance can shift interpretation, but rules themselves require legislative amendment

Practical Implications of the Differences

A device may be a different class in the US and EU. This is extremely common. A device that is Class II under FDA might be Class IIb or even Class III under EU MDR, or vice versa. For example:

• Surgical mesh for hernia repair: Class II in the US (510(k) pathway), but Class III under EU MDR (requires Notified Body involvement with heightened scrutiny for implants)
• Software that provides diagnostic information: May be Class II in the US under a specific product code, but could be Class IIa, IIb, or III under EU MDR Rule 11 depending on the clinical significance of the information provided
• Contact lenses: Class II in the US, Class IIa or IIb under EU MDR depending on type
• IVDs for self-testing: Class II in the US if cleared through 510(k) or De Novo, but may be Class C or D under IVDR depending on the analyte

The self-classification model in the EU creates different challenges. Under the FDA system, the agency assigns the classification — manufacturers look it up. Under the EU MDR, manufacturers must self-apply the 22 classification rules and justify their determination. This leads to more ambiguity and more reliance on the Notified Body to confirm the manufacturer's classification decision.

IVD classification is dramatically different. The EU IVDR moved from a list-based system (Annex II lists under the old IVDD) to a risk-based rule system (Classes A through D). Many IVDs that were previously unclassified or low-class under the IVDD are now Class C or D under the IVDR, requiring significantly more clinical evidence and Notified Body involvement. The FDA's IVD classification, while risk-based, does not have this same magnitude of reclassification in progress.

Mapping Table: FDA vs. EU MDR/IVDR Classes (Approximate)

This mapping is approximate because the systems are structurally different, but it provides a rough orientation:

FDA Class	Approximate EU MDR Equivalent	Approximate EU IVDR Equivalent (for IVDs)
Class I (exempt)	Class I (self-declaration)	Class A (self-declaration)
Class I (510(k) required)	Class IIa	Class B
Class II	Class IIa or IIb	Class B or C
Class III	Class III (or IIb for some implants)	Class C or D

Practical tip: Never assume your US classification translates directly to your EU classification. Always apply the EU MDR/IVDR classification rules independently. Many companies have been caught off guard by devices that are routine Class II in the US but require Class III-level clinical evidence under EU MDR.

Common Mistakes in Classification

Mistake 1: Choosing the Wrong Product Code

The most frequent classification error is selecting a product code that does not accurately describe your device's primary intended use. This happens when manufacturers:

• Select a product code based on the device's physical form rather than its clinical function
• Choose a product code for a lower-class device to avoid a more burdensome regulatory pathway
• Misunderstand the scope of a classification regulation

Consequence: If the FDA determines during review that your device belongs under a different product code, your submission may be refused, rejected, or redirected to a different review division. This adds months to your timeline.

Mistake 2: Ignoring 510(k) Exemption Limitations

Many manufacturers see that their product code is 510(k) exempt and assume they can market freely. They overlook the limitations on exemptions — particularly the requirement that the device not operate using a different fundamental scientific technology than the classified device type. A digitally connected version of a traditionally analog exempt device may no longer qualify for the exemption.

Mistake 3: Not Checking for Special Controls

Class II devices have special controls, but manufacturers sometimes treat the 510(k) as the only requirement. Special controls may include mandatory performance standards, specific labeling requirements, post-market surveillance obligations, or participation in patient registries. Failing to identify and comply with all applicable special controls can result in a deficient 510(k) or post-market enforcement.

Mistake 4: Assuming Classification Is Static

Manufacturers sometimes establish their regulatory strategy based on a device's current classification without monitoring for reclassification activity. The FDA regularly reclassifies device types, creates new product codes through De Novo, and issues 515(b) orders calling for PMAs. A device that was marketed via 510(k) last year may require PMA next year.

Mistake 5: Misclassifying Software

Software classification is one of the most error-prone areas. The FDA has issued multiple guidance documents addressing which software products are medical devices, which are exempt under the 21st Century Cures Act (e.g., certain clinical decision support functions), and how SaMD should be classified. Common errors include:

• Failing to recognize that standalone software with a medical intended use is a medical device
• Misapplying the clinical decision support exemption criteria under Section 3060 of the Cures Act
• Assuming that a software accessory to a cleared device inherits the host device's classification
• Not accounting for AI/ML components that may require additional classification considerations

Mistake 6: Treating Accessories as Standalone Devices (or Vice Versa)

An accessory to a medical device is itself a medical device that must be separately classified. The FDA's accessory classification regulation (finalized in 2017) clarified that accessories are classified based on their own risk profile, not the risk profile of the parent device. An accessory to a Class III device is not necessarily Class III itself — it may be Class I or Class II.

Conversely, a component that is integral to a device and not separately marketed is not classified as a standalone device. The distinction between accessory, component, and standalone device matters for classification.

Mistake 7: Not Accounting for Multiple Intended Uses

Devices with multiple intended uses may span multiple product codes and potentially multiple device classes. A multi-parameter patient monitor that measures ECG, SpO2, and blood pressure involves at least three separate product codes. The manufacturer must ensure each function is classified correctly and that the premarket submission addresses all applicable product codes and classification requirements.

Product Code Lookup: A Practical Workflow

Here is a step-by-step workflow that consolidates the guidance in this article into an actionable process:

1. Define your device's intended use precisely. Write a clear, unambiguous intended use statement before searching any database. This is your anchor.

2. Search the Product Classification Database. Use multiple search terms — function, anatomy, device type, comparable device names.

3. Identify candidate product codes. List every product code that could potentially apply to your device. Do not stop at the first match.

4. Read each classification regulation (21 CFR text). Confirm that the regulation's device description matches your device's intended use and technological characteristics.

5. Check exemption status. For each candidate product code, note whether it is 510(k) exempt and whether the exemption limitations apply to your specific device.

6. Search the 510(k) and PMA databases. Look for cleared or approved devices under your candidate product codes. Do they resemble your device? If not, the product code may not be the right fit.

7. Check the De Novo database. Has a recently authorized De Novo created a product code that better fits your device?

8. If uncertain, engage the FDA. Use a Pre-Submission, 513(g) request, or both. The cost of getting classification wrong far exceeds the time investment of formal FDA engagement.

9. Document your classification rationale. Record your search process, the product codes you considered, the one you selected, and the reasoning. This documentation is valuable during FDA review and inspections.

10. Monitor for changes. Set up alerts for Federal Register notices related to your product code. Reclassification, new guidance, and De Novo authorizations can all affect your device's regulatory status.

Frequently Asked Questions

Can a device have more than one product code?

A single device typically has one primary product code, but multi-function devices may be associated with multiple product codes. For example, a patient monitor that measures ECG, SpO2, blood pressure, and temperature technically involves several product codes. In practice, the FDA assigns a primary product code based on the device's principal intended use, but the submission must address all applicable classifications.

What if my device could fit under two different product codes with different classifications?

This is common and consequential. If one product code is Class I exempt and the other is Class II requiring 510(k), the classification determines your regulatory burden. The correct approach is to match the product code whose regulation description most accurately describes your device's primary intended use. If genuinely ambiguous, a 513(g) request or Pre-Submission to the FDA resolves the question.

How long does it take to get a 513(g) response?

The FDA targets a 60-day response time. In practice, responses can take 60 to 120 days depending on the complexity of the device and the review division's workload.

Can I market my device while waiting for a classification determination?

No. Marketing a medical device without the required premarket authorization — whether that is a 510(k) clearance, De Novo authorization, or PMA approval — is a violation of the FD&C Act. If your device requires premarket review, you must obtain the appropriate authorization before commercial distribution.

What happens if the FDA reclassifies my device type after I am already on the market?

The FDA typically provides a transition period. If your Class II device type is reclassified to Class III with a PMA call, you will be given a timeline (often 12 to 36 months) to submit a PMA. You can continue marketing during this transition period as long as you meet the stated deadlines. If you fail to submit a PMA by the deadline, your device becomes adulterated and must be removed from the market.

Does my classification in the US determine my classification in the EU?

No. The US and EU classification systems are independent. You must apply the EU MDR or IVDR classification rules separately. As discussed above, a device's class can — and frequently does — differ between the US and EU.

Where can I find the special controls for my Class II product code?

Special controls are identified in the classification regulation (21 CFR text for the product code), in FDA guidance documents, and — for De Novo-created classifications — in the De Novo authorization order. The Product Classification Database entry for your product code links to applicable special controls when they exist.

FDA Classification System by the Numbers

Understanding the scale and structure of the FDA's classification system helps contextualize the regulatory landscape:

Product Code and Regulation Statistics

Metric	Count	Notes
Total product codes	~6,500+	Each represents a distinct device type with its own classification
Total regulation numbers (21 CFR sections)	~1,700	Many regulation numbers map to multiple product codes
Unclassified (pre-amendment) device codes	~851	Devices marketed before 1976 that have not been formally classified into Class I, II, or III
Medical specialty panels	16	Plus Molecular Genetics and Toxicology panels used for specific product types
Routes to commercialization	8	510(k) Exempt, 510(k), De Novo, PMA, HDE, EUA, Enforcement Discretion, Contact ODE

Device Class Distribution

Device Class	Approximate % of Device Types	Estimated Count	Typical Premarket Pathway
Class I	~47%	~780 device types	510(k) exempt (~95%); 510(k) (~5%)
Class II	~43%	~750 device types	510(k) (most); some 510(k) exempt
Class III	~10%	~170 device types	PMA (most); some 510(k) for pre-amendment devices

Annual Submission Volume (Approximate)

Submission Type	Approximate Annual Volume	Average Review Time
510(k) premarket notifications	~3,500-4,000 per year	3-5 months
PMA original applications	~30-50 per year	12-24 months
De Novo classification requests	~60-100 per year (growing)	5-12 months
513(g) classification requests	~60-80 per year	60 days target (often longer)

MDUFA User Fee Summary (FY2026)

Submission Type	Standard Fee	Small Business Fee
510(k)	$26,067	$6,517
PMA (original)	$579,272	$144,818
De Novo	$173,782	$43,446
513(g)	$7,820	$3,910
Panel-track PMA supplement	$463,418	$115,855
180-day PMA supplement	$86,891	$21,723
Real-time PMA supplement	$40,549	$10,137
30-day notice	$9,268	$4,634
Annual establishment registration	$11,423	$11,423 (waiver may be available)
Annual fee for periodic reporting (Class III)	$20,275	$5,069

Practical tip: User fees are published annually by the FDA in a Federal Register notice, typically in late July or early August, and take effect on October 1 of each year. If your submission will be received near the end of a fiscal year (September 30), confirm which fee schedule applies. Submissions received after 4:00 PM ET on September 30 are subject to the new fiscal year's fees, and you will need to pay the difference if you paid under the prior year's schedule. Small businesses must be certified through CDRH's Small Business Determination (SBD) Program to qualify for reduced fees.

AI/ML-Enabled Device Classification Trends

The FDA has seen rapid growth in AI/ML-enabled medical device authorizations:

• Cumulative authorized AI/ML devices through 2025: Over 1,000 (the exact count reached approximately 1,451 by end of 2025)
• New AI/ML authorizations in 2025 alone: Approximately 295
• Dominant specialty: Radiology imaging accounts for approximately 76% of all AI/ML-enabled device authorizations
• Most common pathway: The majority are Class II devices cleared via 510(k), though novel AI/ML device types continue to enter through De Novo
• Growing categories: Cardiovascular, ophthalmology, and pathology AI/ML devices are growing as a share of new authorizations

These devices are classified using the same product code system as all other medical devices. Many AI/ML devices are classified under existing product codes (e.g., QAS for computer-aided detection/diagnosis software in radiology), while others have received new product codes through De Novo when they represent truly novel device types.

Key Takeaways

1. Classification is the foundation of your regulatory strategy. Every downstream decision — pathway, testing, timeline, cost — flows from your device's classification.

2. Use product codes, not intuition. The FDA Product Classification Database is the authoritative source. Do not guess your classification based on what you think your device is. Look it up.

3. Understand the three layers. Device class (I, II, III) determines the level of regulatory control. Product code determines the specific classification regulation. Regulation number defines the device type and its requirements.

4. Exemption is not automatic. Even if your product code is listed as 510(k) exempt, confirm that the exemption limitations do not apply to your specific device configuration.

5. Classification changes. Monitor the Federal Register and the Product Classification Database for reclassification actions, new De Novo authorizations, and PMA calls that could affect your device.

6. When in doubt, ask the FDA. A 513(g) request ($7,820 standard fee for FY2026) gets you a written classification determination. A Pre-Submission has no user fee and is more comprehensive. Both are far cheaper than submitting under the wrong classification.

7. US and EU classifications are independent. Never assume your FDA classification translates to your EU MDR or IVDR classification. Apply each system's rules independently.

8. Document everything. Your classification rationale should be part of your regulatory file. It demonstrates due diligence during FDA inspections and supports your regulatory strategy if questioned.