This bill makes several changes to improve how rural emergency hospitals are designated and compensated under Medicare and Medicaid. It expands which facilities can convert to rural emergency hospital status by looking back to any point between 2015 and the current date, rather than just a specific moment in time, and allows the Secretary of Health and Human Services to waive certain requirements for similar-operating facilities. The legislation also permits rural emergency hospitals to operate specialized units for psychiatric care, rehabilitation, and obstetric services, and establishes a 5 percent payment increase for diagnostic laboratory tests starting January 1, 2027, to reflect higher costs. Additionally, the bill allows rural emergency hospitals to provide swing bed services (temporary skilled nursing care), makes them eligible for National Health Service Corps recruitment programs, includes them in Medicaid coverage, and enables facilities that switch back to critical access hospital status to retain certain provider designations. The bill requires the Secretary to issue implementing regulations within one year of enactment and provides a grace period for states that need to update their Medicaid plans through the legislative process.