GUIDE
Choosing a predicate device: what the comparison has to survive
A 510(k) rests on a comparison, so the predicate device is not an administrative detail. It sets the intended use you are measured against, the technological characteristics that must line up, and the questions a reviewer is likely to raise about any difference.
PUBLIC SOURCES · UNITED STATES (FDA) · NOT A PREDICATE RECOMMENDATION
01
What a predicate device is
A predicate device is a legally marketed device used as the point of comparison in a 510(k) premarket notification. The submission argues that the new device is substantially equivalent to it in intended use and technological characteristics, or that the differences do not raise different questions of safety and effectiveness.
Legally marketed matters. A candidate must be a device that is or was legally marketed and was not in violation of the FD&C Act. A device no longer being marketed may still be used as a predicate; suitability still depends on the intended-use and technological comparison.
02
How candidates are identified in the public record
Predicate work is largely public-record work, which is why it can be reconstructed independently without access to a manufacturer's technical file.
- START FROM INTENDED USE
- Describe the intended use and indications in plain terms first. Devices that share a mechanism but serve a different clinical purpose are usually poor candidates.
- MAP THE PRODUCT CODE
- Identify the regulation and product code that best fits the description, then look at what has been cleared under it and how those clearances describe themselves.
- READ THE CLEARANCE SUMMARIES
- Public 510(k) summaries describe the comparison, certain material characteristics and supporting testing at a summary level; they are not the full submission.
- CHECK LEGAL-MARKETING BASIS
- Confirm the candidate is or was legally marketed and was not in violation of the FD&C Act. Being off market does not by itself make a candidate ineligible.
03
Why predicate comparisons fall apart
Most weak comparisons share one of a few shapes. Each is visible early if the comparison is written out honestly before evidence is committed.
- INTENDED-USE DRIFT
- The device is technologically close but the claimed use is broader, a new population is added, or a diagnostic claim is layered on a monitoring device.
- TECHNOLOGY GAP
- A different mechanism, energy source, algorithm or material introduces questions the predicate's record does not answer.
- SPLIT PREDICATES
- Intended use is taken from one device and technology from another, so neither comparison stands on its own.
- SOFTWARE AND AUTONOMY
- Adaptive or automated decision support often outruns the predicate's described function, which changes what has to be demonstrated.