A predicate device (PD) is a medical device that may be legally marketed in the U.S, and used as a point of comparison for new medical devices seeking approval through FDA’s 510(k) premarket clearance pathway. The predicate allows manufacturers to demonstrate that their new device is substantially equivalent to a device already approved to be legally marketed in the U.S. There are two categories of predicate device.

• A Preamendments Device was legally marketed in the U.S. prior to the Medical Device Amendments in 1976. It was grandfathered under the new amendments and did not require a 510(k) submission for the device.  

• A Postamendments Device was brought to market after May 28, 1976 via 510(k) submission or premarket approval.  

The FDA recommends that manufacturers choose a predicate that is most similar to their device with regard to indications for use and technological characteristics.  Other criteria include to help build the case for proving a device is substantially equivalent to a predicate include: design, energy used or delivered, materials, performance, safety, effectiveness, labelling, and other appropriate considerations. In addition to these criteria, choosing a more recently approved predicate device is preferred due to the rapid changes in technology since 1976. The FDA is considering updating its rules to require that predicate devices be less than ten years old.

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