Ambulatory surgery centers (ASCs) continue to gain ground in the U.S. health care system as procedure volume rises, new facilities open and higher-acuity services migrate out of hospitals.
That’s according to the latest report to Congress from the Medicare Payment Advisory Commission (MedPAC).
The commission’s March 2026 report to the Congress on Medicare payment policy portrays the ASC sector as one of the more steadily expanding segments of Medicare’s outpatient landscape.
“Signs point to a robust industry: The number of ASCs nationwide grew over 2% per year, on average, between 2019 and 2024, and the volume of ASC surgical procedures per FFS beneficiary increased by 3.5% in 2024 and at an annual average rate of 1.3% from 2019 to 2023,” MedPAC wrote.
In 2024, roughly 6,400 ASCs treated about 3.4 million Medicare fee-for-service beneficiaries, with total Medicare program spending and beneficiary cost sharing reaching all-time-high levels, according to MedPAC.
The findings reinforce the long-running trend across U.S. health care in the form of the migration of surgical procedures from hospital outpatient departments into lower-cost outpatient settings.
Several forces are driving that shift, including advances in surgical technology, physician preferences for specialized environments and operational efficiencies that allow procedures to be performed more quickly in ASCs, according to MedPAC.
For patients, too, the facilities often mean shorter wait times, more convenient locations and lower cost-sharing obligations compared with hospital outpatient departments.
In its report, MedPAC also pointed to a growing role for ASCs in higher-acuity care. Procedures such as total knee, hip and shoulder replacements have gained traction in outpatient settings in recent years, while the U.S. Centers for Medicare & Medicaid Services (CMS) has continued expanding the list of procedures eligible to be performed in ASCs.
Medicare spending tied to ASC services has climbed rapidly as those trends accelerate.
Specifically, fee-for-service Medicare payments and beneficiary cost sharing for ASC facility services rose to $7.5 billion in 2024, up from $6.6 billion in 2023. Payments per Medicare beneficiary receiving ASC services increased sharply as well, reflecting both payment updates and a shift toward more complex procedures.
Despite the sector’s growth, MedPAC reiterated a longstanding concern about the lack of transparency into ASC cost structures.
More than 95% of ASCs operate as for-profit facilities and about 94% are located in urban areas, according to MedPAC. That reflects both the capital-intensive nature of the facilities and the concentration of surgical specialists in metropolitan markets.
MedPAC also noted differences in the patient populations served by ASCs compared with hospital outpatient departments (HOPDs). Ambulatory surgery centers, for example, are less likely to treat Medicare beneficiaries who are dually eligible for Medicaid, disabled or age 85 and older.
The report also included statistics on which specialties are growing the fastest.
About 68% of ASCs that billed FFS Medicare in 2024 specialized in a single clinical area, of which gastroenterology and ophthalmology were the most common, according to MedPAC. The remainder were multispecialty facilities, providing services in more than one clinical specialty, of which pain management and orthopedics were the most common.
“From 2023 to 2024, the ASC specialties that grew most rapidly were pain management and cardiology,” MedPAC wrote.
