Substantial equivalence (SE)

A device with different technological characteristics can still be substantially equivalent if the differences raise no different questions of safety and effectiveness and the data show it is as safe and effective. It is a comparison with a legally marketed predicate, not an independent demonstration of safety.

(i)(1)(A) For purposes of determinations of substantial equivalence under subsection (f) and section 520(l), the term "substantially equivalent" or "substantial equivalence" means, with respect to a device being compared to a predicate device, that the device has the same intended use as the predicate device and that the Secretary by order has found that the device (i) has the same technological characteristics as the predicate device, or (ii)(I) has different technological characteristics and the information submitted that the device is substantially equivalent to the predicate device contains information, including appropriate clinical or scientific data if deemed necessary by the Secretary or a person accredited under section 523, that demonstrates that the device is as safe and effective as a legally marketed device, and (II) does not raise different questions of safety and effectiveness than the predicate device.

FDA guidance: The 510(k) Program: Evaluating Substantial Equivalence in Premarket Notifications [510(k)] (July 2014), Section IV.A, The 510(k) Review Standard (quoting section 513(i) of the FD&C Act)