510(k)
FDA's premarket pathway for devices substantially equivalent to existing legally marketed predicates. Cleared devices receive a "K-number" used as the canonical regulatory identifier.
Why it matters to buyers: Clearance, not approval. The dominant pathway for imaging capital equipment. Look up specific K-numbers on the FDA 510(k) database to verify a device's regulatory footprint.
Why it matters to engineers: Follow-on 510(k)s cover software upgrades, new configurations, AI / SaMD components. A single system often has multiple related clearances spanning a decade-plus of product evolution.