FDA 513(g): A Classification Answer, Not a Pre-Submission's Feedback

Section 513(g) of the Federal Food, Drug, and Cosmetic Act lets any person ask FDA, in writing, how a device is classified and which requirements apply to it. FDA's own August 2024 guidance is explicit about what that answer is not: not a review of your testing, not a substantial-equivalence call, and not a classification decision at all. Teams that file a 513(g) expecting Pre-Submission-style feedback get a narrower answer than they were hoping for — and, per FDA's own fiscal 2023 performance data, often a slower one than the statute promises.

What a 513(g) actually buys you

The request has one job: a written statement of the class FDA believes a device falls into, and the FD&C Act provisions that apply to it. That is useful when the classification question is genuinely open — a device that does not map cleanly onto an existing 510(k) product code, or one where the manufacturer and FDA might reasonably disagree about whether it is even a medical device. It is not a vehicle for testing feedback, study-design input, or a read on substantial equivalence; FDA's guidance says so directly, and reviewers hold the line on it.

The question it can't answer

A Pre-Submission and a 513(g) look similar on paper — both are written exchanges with FDA short of a full marketing submission — but they answer different questions. A Pre-Sub is built for feedback on bench testing, clinical protocols, biocompatibility plans, or predicate selection, and it comes with a meeting. A 513(g) comes with neither a meeting nor testing feedback; it is a standalone written request, and FDA will not review safety or effectiveness data submitted alongside it.

• No meeting. A 513(g) is a written-only exchange; a Pre-Sub includes an interactive session with the review team.
• No testing review. FDA does not evaluate bench, biocompatibility, or clinical data attached to a 513(g) — only the classification question itself.
• No fee on a Pre-Sub; a fee on every 513(g). FDA does not charge for Pre-Submissions, but will not start the 513(g) clock until the user fee clears.
• Neither one binds FDA. A 513(g) response is the agency's non-binding written view; issues FDA raises in a Pre-Sub likewise do not obligate the agency later — but only the 513(g) is a classification-only instrument.

A 513(g) answers what the device is. A Pre-Sub answers whether the plan to get it cleared is good enough. File the wrong one and you burn the fee, the 60 days, and the question you actually needed answered. Why the two aren't interchangeable

Filing it so it earns the fee

FDA's August 2024 update to the 513(g) guidance — superseding a December 2015 version — added the option to file through the same eSTAR-based template used for Pre-Submissions, though use remains voluntary rather than required. That mechanical change does not touch the substance: a 513(g) request still succeeds or fails on whether it asks a genuinely open classification question, with enough device description and proposed indication for use that FDA can answer it without needing the testing data the request does not invite. Vague or overbroad requests are the ones most likely to miss the 60-day goal, because they force reviewers to ask clarifying questions that restart the clock in substance even when they do not restart it on paper. Pair the strategy question with a realistic regulatory pathway assessment before filing, especially if the honest answer might be De Novo rather than a straightforward class determination.

None of this is exotic, but it is a sequencing decision companies get backwards often enough that FDA's own guidance spells out the boundary. Know which question you're asking before you file: a classification question goes to a 513(g); a plan-quality question goes to a Pre-Submission or a later Submission Issue Request. Getting that sequencing right is exactly the kind of regulatory-pathways judgment call our team makes before a filing goes out, not after FDA's response comes back narrower than expected.