FDA Rejected Your 510(k) Predicate: What to Do Next

FDA disputes predicate selections through two mechanisms: an Additional Information (AI) request that questions the predicate during review, or a Not Substantially Equivalent (NSE) determination that concludes the predicate argument is insufficient. The right response depends on where in the process you are and the nature of FDA's objection.

Understanding why FDA disputes predicates

FDA predicate disputes fall into two broad categories: intended use mismatches and technological characteristic concerns. Understanding which category applies to your situation determines the correct response.

Intended use mismatches occur when FDA determines that your predicate is indicated for a different patient population, clinical setting, or purpose than your device. These disputes are often about the scope of the intended use statement — either yours is broader than the predicate, or the predicate's intended use has been narrowly interpreted by FDA.

Technological characteristic concerns occur when your device differs from the predicate in ways that FDA believes raise new safety or effectiveness questions. These disputes require performance data — you cannot argue your way through them without test results.

Strengthening your predicate argument

If you receive an AI request questioning your predicate, the strongest responses do one of three things: provide additional evidence that your predicate does support the intended use (citing FDA guidance, published literature, or the predicate's own 510(k) summary); identify a second predicate that more directly supports the contested aspect; or provide performance data that resolves the technological concern without changing the predicate.

Simply restating your original argument in a more emphatic way rarely succeeds. FDA reviewers are experienced with 510(k) submissions and respond to evidence, not assertions.

When to find a new predicate and refile

If FDA's AI request indicates a fundamental objection to your predicate — not a request for more data but a conclusion that the predicate is inappropriate — it is often faster to withdraw the submission, identify a better predicate, and refile rather than attempting to defend an untenable predicate argument through multiple AI exchanges.

Refiling with a stronger predicate costs 1-2 months of preparation but resets to a clean review. Continuing to defend a weak predicate through multiple AI cycles can add 6-12 months to your timeline with an uncertain outcome.

When to consider De Novo

If no legally marketed predicate exists for your intended use or your device's technological characteristics are genuinely novel in ways that no predicate can cover, De Novo classification may be the appropriate pathway. De Novo is not a consolation prize — it establishes a new device type and becomes itself a predicate for future 510(k)s.

De Novo is more resource-intensive than 510(k) — it requires demonstrating that general controls or special controls (which you propose) provide reasonable assurance of safety and effectiveness. But for truly novel devices, it is the correct pathway and FDA's NSE determination may effectively be directing you there.

The 510(k) appeal process

If you receive an NSE determination and believe it is incorrect, you have options. You can request supervisory review within the reviewing division, which is an informal internal escalation. You can file a 510(k) Petition (formerly called a petition for reconsideration) requesting CDRH review. You can also request a meeting with the division to discuss the NSE before pursuing formal appeals.

Appeals are time-consuming and succeed infrequently. Before pursuing appeal, get an honest external assessment of whether your predicate argument was genuinely strong — the answer will tell you whether appeal is worth the investment.