The five-unit device never gets a K-number

Almost every device that reaches the U.S. market carries a number that proves FDA looked at it — a K-number, a PMA number, a De Novo grant. The number is the receipt. One legal category of device is built, by design, to never generate one, for as long as the firm making it stays inside a condition most portfolio tools never think to check for.

Five conditions, then a cap

21 CFR 812.3(b) defines a custom device: one that necessarily deviates from a generally available device, or from an applicable performance standard or premarket approval requirement, to comply with an individual physician’s or dentist’s order; is not generally available to or used by other practitioners; is not generally available in finished form for sale or for dispensing on prescription; is not offered for commercial distribution through labeling or advertising; and is intended for a specific patient named in that order, made in a specific form for that patient. Five conditions, all descriptive — none of them, on their own, used to say how many a firm could make.

The Food and Drug Administration Safety and Innovation Act, effective July 9, 2012, added the condition that governs the exemption now: a firm may make no more than five units a year of a particular device type under it, and must notify FDA annually that it did. FDA’s September 2014 guidance spells out how that count is measured and what the annual notice has to contain; a technical amendment in October 2016 brought the regulation’s own text into line with the statute. The cap runs per device type, not per firm — a manufacturer can run several distinct custom-fit product lines in parallel, each one separately capped at five.

Exempt from the review that assigns a number

A device meeting 812.3(b)’s conditions is exempt from premarket notification under section 510(k) and from the performance-standard and premarket-approval requirements of sections 514 and 515 of the FD&C Act. No clearance review runs, so no K-number gets assigned; no approval review runs, so no PMA number does either. The condition keeping the exemption alive is the annual notice — skip it, and devices distributed as “custom” are not exempt after all. But the notice itself is a filing to FDA, not a submission that creates a public database entry. It generates no number of its own.

A 510(k) creates a K-number because FDA reviewed something. A custom device creates nothing to review, and the record shows exactly that — nothing.

The practice

A portfolio or competitor watch built on openFDA’s identifiers — K-number, PMA number, product code tied to a classification order — has nothing to search for a company’s custom-device business, because there is no per-device event that database was ever going to record. Custom orthopedic implants, custom cranial plates, custom dental restorations, custom prosthetics: any of these can be a real, ongoing product line at a competitor, entirely legal, and structurally invisible to a search built around clearance identifiers. That is not a gap in coverage the way a slow-to-update field is a gap. It is zero rows, for the life of the product, by the statute’s own design.

Finding that kind of activity means reading a firm’s own labeling, case studies, and public communications, or asking directly — not searching a clearance database for something the exemption was written to keep out of it. Whether a specific device actually meets 812.3(b)’s conditions, and stays under the five-unit count, is a determination the manufacturer makes for itself and FDA can revisit at inspection; this is regulatory intelligence and method, describing how the exemption works and what it leaves out of the public record, never advice about whether any specific device qualifies for it.

A custom device leaves nothing for FDA Radar to ingest either — per what we monitor and how often, the pipeline reads Federal Register notices, warning letters, recalls, and 510(k) clearances, and none of those fires for a device that was never reviewed in the first place.