CMS Proposes Adding 618 Surgeries to Medicare's Ambulatory Surgery Center List for 2027, With Public Comments Due August 31

The Centers for Medicare and Medicaid Services published a proposed rule in July 2026 that would significantly expand the list of surgical procedures Medicare covers when performed at ambulatory surgery centers, which are freestanding outpatient facilities that typically charge less than hospital outpatient departments.

Under the proposal, CMS would add approximately 618 additional surgical and surgery-like procedures to the ASC Covered Procedures List for calendar year 2027. CMS evaluated each candidate procedure against existing criteria, including whether the service can be performed safely without active medical monitoring or an overnight hospital stay, and whether it is consistent with the capabilities of Medicare-certified ASCs.

The rule also proposes removing 637 procedures from the inpatient-only list, making them eligible for Medicare payment in outpatient or ASC settings for the first time. An additional 801 procedures on the inpatient-only list would move off in calendar year 2028, completing a multi-year phase-out.

For Medicare beneficiaries, the setting where a surgery is performed can affect cost sharing. Ambulatory surgery centers generally carry lower Medicare payment rates than hospital outpatient departments, and some plans pass those savings to enrollees through lower copays or coinsurance. Actual costs depend on plan type and coverage terms.

The public comment period closes August 31, 2026. CMS is expected to issue a final rule in November 2026, with new policies taking effect January 1, 2027.