Objective: To examine long-run growth in the ambulatory surgery center (ASC) industry and potential factors influencing its trajectory.
Data sources: National data for all Medicare-certified ASCs (1990–2015) and outpatient discharge records from the state of Florida in 2007.
Study Design: We documented the number of ASCs in the United States over time and decomposed the trend into underlying ASC market entry and exit behavior. We then examined the plausibility of 2008 Medicare payment reforms to influence the trend changes.
Data Extraction Methods: Data on ASC openings and closures are obtained from the Centers for Medicare and Medicaid Services Provider of Service files. Secondary data on ASC volume in Florida are obtained from the Florida Agency for Health Care Administration.
Principal Findings: The number of ASCs in the United States grew 5%–10% annually between 1990 and 2007 but by 1% or less beginning in 2008. This change coincided with substantive reductions in Medicare payments for key ASC services. The annual number of new ASCs was as much as 50% lower following the payment change.
Conclusions: ASCs are an important competitor for outpatient services, but growth has slowed dramatically. Sharp changes in new ASC entry align with less generous Medicare fees.