What Is the Difference Between 510(k), De Novo, and PMA, and Which One Does My Device Need?

Device sponsors often start by asking which pathway sounds right for their device type. The better question is a decision sequence: what already exists on the market, what regulation classifies it, and what FDA's own rules require as a result. This guide walks that sequence directly rather than comparing the three pathways feature by feature; for a side by side comparison of requirements, evidence burden, and typical use cases, see our 510(k) vs PMA vs De Novo comparison.

The Three Pathways, One Paragraph Each

510(k) premarket notification demonstrates substantial equivalence to a legally marketed predicate device under Section 510(k) of the Federal Food, Drug, and Cosmetic Act. It is the pathway for most Class II devices and some Class I devices, and it is the fastest and least evidence intensive of the three when a strong predicate exists.

De Novo classification is available under Section 513(f)(2) of the FD&C Act for novel devices with no predicate, where the device's risk can be adequately controlled through general and special controls rather than the more rigorous PMA process. A successful De Novo creates a new classification regulation and often becomes the first predicate for later 510(k) submissions in that device category.

Premarket approval (PMA) is the most rigorous pathway, required for Class III devices under Section 515 of the FD&C Act. It requires valid scientific evidence, typically including clinical data, demonstrating reasonable assurance of safety and effectiveness, and it is the only pathway that ends in FDA approval rather than clearance.

The Decision Sequence That Actually Determines Your Pathway

Work through these questions in order, not device type first:

• Does a classification regulation already exist for this type of device? If yes, the device is already Class I, II, or III by regulation, and that classification, not a guess, governs the next step.
• Is the device Class III? If yes, PMA applies regardless of whether a similar device exists on the market, unless FDA has reclassified that device type down from the original Class III default.
• If Class I or II, does a predicate exist with the same intended use and similar technological characteristics? If yes, a 510(k) applies. A predicate that merely resembles the device superficially, without matching intended use, does not support a substantial equivalence claim.
• If no predicate exists and the device is not Class III, is the risk profile one general and special controls can adequately address? If yes, a De Novo request is the pathway; if the risk profile genuinely requires the Class III evidence standard, PMA applies even without an existing predicate.

Where 513(g) and Pre-Submission Fit Into That Sequence

Two tools resolve uncertainty at different points in this sequence. A 513(g) request answers the first question directly: what classification regulation, and therefore what pathway, applies to this device, when that is not already obvious from FDA's own classification database. A Pre-Submission meeting comes after the pathway is chosen, confirming FDA's agreement with the predicate selection, the proposed testing plan, or the De Novo risk control strategy before the sponsor commits engineering and clinical resources to that plan.

Typical Review Clocks and User Fees

A Traditional 510(k) targets FDA's 90 calendar day MDUFA performance goal; a De Novo targets 150 days; a PMA review spans several months to multiple years depending on device complexity, clinical data requirements, and whether an advisory panel review is convened. Actual timelines vary with submission completeness and any Additional Information requests, which pause the review clock. FDA's user fees for each pathway are set annually under MDUFA and change every federal fiscal year; consult FDA's current user fee schedule rather than relying on a fixed figure from any third party source, including this page.

The Three Most Common Misroutes

Across the pathway determinations ADB's regulatory team performs, three misroutes recur. First, assuming a predicate exists because a similar product is on the market, without confirming intended use and technological characteristics actually match closely enough to support substantial equivalence. Second, treating a device as automatically Class III because it sounds high risk, when a classification regulation may already place it in Class II with special controls. Third, choosing a 510(k) route for a genuinely novel device because De Novo sounds slower, then spending months on an Additional Information cycle trying to force a predicate comparison that was never going to hold up.

ADB's regulatory team works through this exact decision sequence for every pathway determination, confirming the classification, predicate strength, and risk control strategy before a submission is drafted, through the broader 510(k), PMA, and De Novo service line.

Frequently Asked Questions

Where do 513(g) and Pre-Submission fit into the pathway decision?

A 513(g) request is the tool for resolving genuine uncertainty about which classification regulation and pathway apply. A Pre-Submission is the tool for confirming FDA's agreement with a chosen pathway and testing strategy before committing engineering resources. Many sponsors use a 513(g) first to confirm the pathway, then a Pre-Sub to confirm the approach within that pathway.

How long does each pathway typically take?

A Traditional 510(k) targets a 90 day MDUFA review clock; a De Novo targets 150 days; a PMA is a multi-month to multi-year process depending on device complexity and whether a panel review is required. Actual timelines vary with submission completeness and Additional Information requests, and user fees change every federal fiscal year, so check FDA's current fee schedule rather than a fixed figure.

What is the most common pathway misroute ADB sees?

Assuming a predicate exists because a similar device is on the market, without confirming the predicate's actual intended use and technological characteristics match closely enough to support a 510(k) comparison. A predicate that looks similar on the surface but differs in intended use or key technology forces a De Novo or a weaker 510(k) argument that invites an Additional Information request.