The U.S. Food and Drug Administration (FDA) has established three regulatory classes based on the level of control needed to ensure the safety and effectiveness of medical devices. If your device is categorized as Class I or Class II and not exempt from the premarket notification process, you will need to submit a 510(k) application before marketing it. For the highest risk class (class III), pre-market approval (PMA) is generally required.

You can use the FDA’s product classification database to look up a device type and find its corresponding regulation and classification, including information on whether a pre-market clinical investigation is expected or not. Pre-market clinical investigation is required for most PMA devices, but only for a minority of 510(k) devices.
All classes of device are also subject to General Controls, which are baseline requirements under the Food, Drug, and Cosmetic Act and are needed to demonstrate safety and effectiveness.

If your device requires a premarket notification, the 510(k) process is a pathway for medical device manufacturers to obtain clearance from the FDA by demonstrating substantial equivalence to existing and already legally marketed devices.  Whether clinical data are needed or not for a 510(k) submission depends on the risk classification of the device and the nature of the changes or modifications compared to the predicate device.

It is the responsibility of the applicant to compare the new device to a predicate device and provide evidence that the new device has the same intended use, and that the device is as safe and effective as the predicate device. If there are significant differences that could affect safety or effectiveness, clinical data may be necessary to support the substantial equivalence claim. For example, if the new device raises NEW questions of safety or effectiveness that cannot be resolved through non-clinical testing or if there are significant technological differences from the predicate device, additional clinical data may be required. In those cases, clinical studies may be needed to evaluate the device’s performance, safety, and usability with human subjects under real-world conditions. Manufacturers should therefore carefully assess the regulatory requirements and seek guidance from the FDA to ensure compliance with applicable regulations when preparing a 510(k) submission.

To be noted is that there are situations where clinical data might also be necessary for Class I and II devices that are exempt from premarket notification requirements. For instance, if a new Class I/II device is intended for a novel or innovative purpose, or if modifications to the device raise new questions about its safety or effectiveness, the FDA might require additional data that also include clinical studies to support its approval or clearance

The FDA provides guidance documents and regulatory requirements that outline when clinical data are necessary for a 510(k) submission. For detailed guidance see The 510(k) Program: Evaluating Substantial Equivalence in Premarket Notifications [510(k)], Section F.

To avoid potentially costly surprises, it is recommended to not wait until submission before consulting with the FDA. It is better to approach them as early as possible to determine the appropriate regulatory pathway and data requirements for your specific device. The FDA is usually very helpful in these situations as long as you have sufficient information for them to evaluate.