510k vs PMA: how FDA clearance, De Novo and approval differ

510k vs PMA for FDA medical device submissions

In a 510k vs PMA choice, 510(k) clearance means FDA found the device substantially equivalent to a legally marketed predicate through a premarket notification. Premarket approval (PMA) reviews a Class III device on its own valid scientific evidence, usually with clinical data, and the device is approved only if that evidence holds.

De Novo is the route for a novel low-to-moderate-risk device with no predicate. A grant places it in Class I or II.

The three pathways side by side

Sources: FDA's 510(k), De Novo and PMA pages. Review clocks and fees follow below.

What a 510(k) is

FDA describes a 510(k) as a premarket submission showing that the device is as safe and effective as a legally marketed device. There is no 510(k) form. FDA answers with a substantial equivalence (SE) letter, and you can start marketing once you have that letter. Since October 1, 2023, 510(k)s must be sent in the eSTAR electronic template, with some exemptions.

Substantial equivalence has a precise meaning in 21 CFR 807.100(b). Your device must have the same intended use as the predicate. It must also have either the same technological characteristics, or different ones that don't raise different questions of safety and effectiveness, backed by data showing it is as safe and effective. Sometimes that data has to be clinical.

When a 510(k) is required

For devices subject to 510(k), 21 CFR 807.81(a) requires submission at least 90 days before commercial distribution when any of these is true. Changes that follow an FDA-cleared predetermined change control plan (PCCP) are excepted.

• a device goes on the market for the first time, or the registering firm introduces it for the first time
• a marketed device is changed in a way that could significantly affect safety or effectiveness
• its intended use changes significantly

Many device types need no 510(k) at all. Each classification regulation in 21 CFR Parts 862 to 892 says whether a type is exempt, with limits in the ".9" sections, so class alone doesn't decide it. FDA counts about 572 Class I device types, roughly 74%, as exempt.

Types of 510(k)

FDA runs several 510(k) programs. The Traditional 510(k) is the default. A Special 510(k) covers well-defined changes to your own cleared device, and FDA intends to process it within 30 days (Special 510(k) guidance). That 30-day intent is not a general 510(k) clock. An Abbreviated 510(k) relies on guidance documents, special controls or consensus standards. It has the same 90-day timing as a Traditional 510(k). There is also the Safety and Performance Based Pathway.

For eligible devices, an FDA-recognized third party reviews the submission, and FDA makes the final decision. FDA's review timeframe is 30 days after it receives the recommendation. There is no FDA user fee for that 510(k).

"510k approval" is the wrong term

Searches for "510k approval" and "FDA 510k approved" use the wrong word. The regulation is blunt about it: 21 CFR 807.97 says a 510(k) clearance is not official FDA approval, and saying a device is approved because it was cleared is misleading. Use "cleared" in labeling and sales material.

Predicate devices and how to pick one

A predicate is a legally marketed device. That means one of four things: it was marketed before May 28, 1976 (a preamendments device), it was reclassified from Class III to Class II or I, it was found SE through a 510(k), or it was granted through De Novo. A device FDA has removed from the market, or one a court has judged misbranded or adulterated, can't be a predicate (FDA 510(k) page).

FDA's final 510(k) guidance on substantial equivalence, from 2014, prefers a single predicate. If you use several, name a primary one, and all of them must share the intended use. "Split predicates", taking the intended use from one device and the technology from another with a different intended use, aren't acceptable. A reference device is not a predicate. If you aren't sure a valid predicate exists, FDA encourages a Pre-Submission.

FDA's predicate selection best practices are still a draft from September 2023, not for implementation. The draft suggests a predicate that:

• was cleared using well-established methods
• meets or exceeds expected safety and performance (check MAUDE and MDR reports)
• has no unmitigated use-related or design-related safety issues (check FDA safety communications)
• has no design-related recall

Start the search in FDA's 510(k) Premarket Notification database, which you can query by device name, manufacturer, 510(k) number, or product code.

What a PMA is

Premarket approval is FDA's scientific and regulatory review of Class III devices. These are devices that support or sustain human life, are of substantial importance in preventing impairment of health, or present a potential unreasonable risk of illness or injury. You need approval before marketing. The standard is sufficient valid scientific evidence that the device is safe and effective, and applications ordinarily include both nonclinical and clinical data (21 CFR Part 814).

The class definitions in 21 CFR 860.3 explain why. Class I devices rely on general controls. Class II adds special controls. For Class III, those controls are not enough for reasonable assurance of safety and effectiveness, and section 515 is the premarket approval route.

FDA lists three PMA application methods: Traditional PMA, Modular PMA and Product Development Protocol (PDP). A Modular PMA uses modules against a shell agreed with FDA. A PDP declared completed by FDA counts as an approved PMA under 21 CFR 814.19.

FDA may also send a PMA to an outside advisory panel. First-of-a-kind devices generally go to a panel, but not every PMA does.

Approval is not the end of the paperwork. Later changes may need PMA supplements: panel-track, 180-day, real-time or Special PMA Supplement (Changes Being Effected). Certain manufacturing changes qualify for 30-day notices, which FDA can turn into 135-day supplements.

510(k) vs De Novo

A device found not substantially equivalent (NSE) in a 510(k) becomes Class III automatically under section 513(f)(1), whatever its actual risk. De Novo exists so that a novel low-to-moderate-risk device doesn't have to go through PMA for that reason alone. It classifies the device into Class I or II when general controls, or general and special controls, are enough.

You don't need an NSE decision first. If no predicate exists, you can file a De Novo request directly. A granted De Novo can be marketed and becomes a predicate for later 510(k)s. Device types that FDA has already placed in Class III by regulation or order can't use De Novo (De Novo guidance; 21 CFR 860.200(b)). The eSTAR template has been mandatory for De Novo requests since October 1, 2025.

Review clocks are FDA Days, not calendar days

The MDUFA V commitment letter sets these goals:

• 510(k): a decision within 90 FDA Days for 95% of submissions
• De Novo: a decision within 150 FDA Days. The separate regulatory clock in 21 CFR 860.240 is 120 days
• PMA: 180 FDA Days for 90% without advisory committee input, 320 FDA Days for 90% with it

FDA Days exclude time the submission sits on hold waiting for you. If FDA puts a 510(k) on Additional Information hold, you have 180 calendar days to respond (510(k) submission process), and that time doesn't count. For PMA, 21 CFR 814.40 sets 180 days from receipt of an application accepted for filing. Major amendments can extend the clock. None of these numbers is your time to market. Plan for longer.

FY2027 user fees

FY2027 fees apply from October 1, 2026 to September 30, 2027 (Federal Register, July 30, 2026; FDA MDUFA fees):

A PMA costs just over 22 times a 510(k) in fees alone. Small business rates need FDA qualification: gross receipts or sales of $100 million or less, affiliates included. A firm at $30 million or less may get the fee for its first premarket application waived.

How to choose between 510(k), De Novo and PMA

You don't pick the pathway freely. Classification depends on intended use and risk. FDA has about 1,700 generic device types in 16 panels, each with a classification regulation and a three-letter product code. Work through it in this order:

1. Find your device type in the Product Classification database. It shows the class, the submission type and any exemption.
2. If the type is exempt Class I or II, you need no 510(k). Registration, listing and general controls still apply.
3. If it is Class I or II, not exempt, and a valid predicate exists, file a 510(k).
4. If no predicate exists, consider De Novo for a novel low-to-moderate-risk device. General controls, or general and special controls, must provide reasonable assurance of safety and effectiveness. Check eligibility with FDA through a Pre-Submission if uncertain.
5. If the type is Class III by regulation, or the risks cannot be controlled without a full safety and effectiveness case, file a PMA. Clinical data alone does not force that choice. Some 510(k)s need it too.
6. If you still can't tell, send a 513(g) request for information. FDA aims to answer within 60 days. Its answer is not a clearance or approval.

Watch two exceptions. Class III doesn't always mean PMA: some preamendments Class III types, and devices SE to them, can still go through 510(k) until FDA orders PMA for that type (FDA classification page). And Class II doesn't always mean 510(k), because some Class II types are exempt.

You can ask RegAffairs AI the same question and follow up on De Novo and predicate choice in this cited answer thread.