A predicate device is a legally marketed device to which a new device is compared in a 510(k) Premarket Notification to support a determination of substantial equivalence. A predicate can be a device marketed before May 28, 1976 (a preamendments device), a device reclassified from Class III, or a device already found substantially equivalent through a 510(k) or granted De Novo. Choosing the predicate is one of the most consequential 510(k) decisions, because every comparison of intended use, technology and performance in the submission is made against it. Some submissions also cite reference devices to support specific test methods.

Why it matters

Selecting an appropriate predicate is one of the most consequential decisions in a 510(k). An ill-chosen predicate can trigger a Not Substantially Equivalent (NSE) determination, requiring a De Novo or PMA pathway.

Common pitfalls

•Choosing a predicate device with different indications for use than the new device can lead to a finding of "Not Substantially Equivalent."
•Selecting a predicate that has been recalled or has known safety issues can jeopardize the 510(k) submission.
•Failing to adequately document the similarities and differences between the new device and the predicate can result in submission delays or rejection.
•Relying on a predicate device for which there is insufficient publicly available information can make substantial equivalence difficult to prove.
•Not considering the technological characteristics and performance data of the predicate can lead to an inappropriate comparison.

Sources

Best Practices for Selecting a Predicate Device · FDA
FDA - Medical Devices · FDA
European Commission - Medical Devices · European Commission

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Common comparison patterns

Regulatory pathway choice - 510(k) vs PMA, 510(k) vs De Novo, Abbreviated vs Special 510(k).
Quality systems - QSR vs ISO 13485, QMSR vs QSR.
Software classification - SaMD vs SiMD, Locked vs adaptive AI.
EU frameworks - MDR vs IVDR, CE Mark vs UKCA.
Cybersecurity artifacts - SPDX vs CycloneDX SBOM, CVE vs CVSS.
Post-market actions - Recall vs field action, Removal vs correction.

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