The 510(k) premarket notification represents the most common pathway for bringing medical devices to the United States market, named for the section of the Federal Food, Drug, and Cosmetic Act that established this process. Rather than requiring proof of safety and effectiveness through clinical trials, the 510(k) pathway allows device manufacturers to demonstrate that their device is substantially equivalent to a device already legally marketed, known as the predicate device. This comparison-based approach enables efficient market entry for devices similar to existing products.

Substantial equivalence is the core concept underlying the 510(k) process. A device is substantially equivalent if it has the same intended use as the predicate and either has the same technological characteristics or has different technological characteristics but does not raise new questions of safety and effectiveness. The submission must identify the predicate device, describe both devices in sufficient detail to permit comparison, and present evidence supporting the equivalence determination. For devices with different technological characteristics, performance data demonstrating comparable safety and effectiveness may be required.

The FDA reviews 510(k) submissions to determine whether substantial equivalence has been established. Review times average three to six months, substantially shorter than premarket approval applications. If the FDA agrees that the device is substantially equivalent, it issues a clearance letter permitting commercial distribution. If substantial equivalence cannot be established, the device may require the more rigorous premarket approval pathway or be declared not substantially equivalent. Critics have questioned whether the 510(k) process adequately ensures device safety, while proponents emphasize its role in enabling timely patient access to medical device innovations.