Whether a person injured by a medical device can sue about it is decided almost entirely by which regulatory pathway the device took to market, and not at all by how dangerous the device turned out to be. This article explains the classification system, the substantial equivalence pathway that most devices actually use, and the premarket approval process that a small minority go through. It then works through the preemption architecture those pathways create, including why the most rigorously reviewed devices are the hardest to sue over and why the narrow parallel claim is the only channel left. It covers adverse event reporting and the public database that is the first thing to pull in any device case, the recall system, the quality system requirements that supply most viable claims, the laboratory testing regime that governs diagnostics, and the single evidentiary step that decides more device cases than any legal argument.