Patients could be spared huge, unexpected bills for ambulance rides under a new plan aimed at closing a gap in the surprise billing law. Many Americans avoid calling 911 when they're having a medical crisis because of cost concerns. Others get stuck with massive unanticipated bills that are a major driver of medical debt in the U.S. A committee of ambulance providers, patient advocates, insurance experts, and other advisers is recommending Congress adopt a tiered payment system for reimbursing out-of-network ambulance rides.