The bill, titled the "When Minutes Count for Emergency Medical Patients Act," amends the Social Security Act to establish a new Medicare payment model and mandate studies on emergency medical services (EMS). The "When Minutes Count for EMS Patients Model" aims to provide supplemental payments for ground and air ambulance services. These payments cover specified life-sustaining EMS medications and blood products that require immediate administration to individuals with emergency medical conditions. The model is designed to run for at least five years and will be implemented across all HHS regions and varying geographic areas. Supplemental payment rates under the model will be calculated based on the total costs of maintaining a sufficient supply of these medications and blood products, including acquisition, storage, transport, and administrative costs. This supply must be sufficient to serve all patients in an eligible entity's primary service area, not just Medicare beneficiaries. Eligible entities, which are EMS agencies, must apply and provide data on quality of care and patient outcomes, including specific data elements like ICD-10 and National Emergency Medical Services Information System (NEMSIS) dispositions. The Secretary must select at least one eligible entity per HHS region and, where feasible, at least one of each type of EMS agency. The bill also directs the Medicare Payment Advisory Commission (MedPAC) to submit a comprehensive report to Congress within two years. This report will evaluate the roles and responsibilities of EMS medical directors , analyzing whether current Medicare payments are sufficient for their oversight services and recommending potential new payment models. MedPAC will also assess the shortage of EMS professionals since 2020, its impact on Medicare beneficiaries' access to care, and how Medicare payments affect recruitment and retention. Furthermore, MedPAC's report will include recommendations for mechanisms to ensure the highest quality of EMS furnished to Medicare beneficiaries, such as the use of quality measures or conditions of participation. It will analyze the consequences of adding a definition for "emergency medical services" to the Social Security Act and recommend whether EMS agencies should be included as "providers of services" under Medicare. Finally, the Secretary of Health and Human Services is mandated to issue guidance to hospitals on addressing "wall time" —the delay beyond 30 minutes for patient hand-off from EMS to hospital staff—and report on its impact.