An ambulance ride is one of the few medical services a patient cannot shop for, cannot consent to meaningfully, and frequently cannot refuse. This article explains the law that governs it. It covers the emergency treatment obligation that requires hospitals to screen and stabilize regardless of ability to pay, and the narrow but real scope of that duty. It explains why ground ambulance bills remained outside the federal surprise billing protections while air ambulance bills were brought inside, and what that gap means for patients. It covers medical necessity and level-of-service denials, the coverage rules that decide whether a transport is paid, and the appeal path that most patients never use. It covers the liability framework for emergency medical services, including the immunities that shield responders and the narrow exceptions to them, and it closes with what a patient should actually do with an ambulance bill.