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Medicare's Oversight of Ambulatory Surgery Centers


Because ambulatory surgery centers (ASCs) often perform complex medical procedures, including invasive surgeries under general anesthesia, we examined how Medicare ensures that ASCs meet minimum health and safety requirements through its State survey process. Most ASCs (known as nondeemed ASCs) undergo a State agency survey to demonstrate that they meet these requirements; the others (known as deemed ASCs) are accredited by a Medicare-approved accreditor. In addition to conducting regular surveys of nondeemed ASCs, States also conduct investigations of complaints that allege poor care or other problems at both types of ASCs. Medicare beneficiaries are increasingly using ASCs for outpatient surgical procedures. In fact, Medicare payments to ASCs increased from $3.4 billion in 2011 to $4.6 billion in 2017.

OIG previously assessed the frequency of ASC State certification surveys in 2002, when we found that nearly a third of nondeemed ASCs had gone 5 or more years without a survey. Since that time, outbreaks of healthcare-associated infections have raised concerns about patient health and safety at ASCs.


We analyzed data provided by Medicare: (1) State data on ASC certification surveys for nondeemed ASCs; and (2) complaints about deemed and nondeemed ASCs from fiscal years (FYs) 2013 to 2017. Using these data, we assessed State survey performance against Medicare's requirements and analyzed trends in deficiency citations from State surveys and trends in complaint surveys.


State Survey Coverage: States largely met Medicare's requirements to survey 25 percent of nondeemed ASCs in FY 2017, and nearly half met Medicare's requirement to have surveyed all ASCs within the prior 6 years.

Trends in Deficiencies: States cited 77 percent of nondeemed ASCs with at least one deficiency in their most recent survey, and one-quarter of ASCs had serious deficiencies. From FY 2013 to FY 2017, infection control deficiencies were the most frequently cited category of deficiency, making up about a fifth of all deficiencies.

Trends in Complaints: From FY 2013 through FY 2017, States received complaints for fewer than 4 percent of ASCs each year, but the share of those complaints that required an onsite survey more than tripled.


CMS has made progress in strengthening oversight of ASCs and addressing vulnerabilities that OIG has previously identified, and more can be done. The results of this new analysis can support CMS in further strengthening its oversight-particularly of the few States that are falling short in meeting its requirements. It can also help CMS focus on ASCs' recurring challenges in meeting health and safety requirements, especially for infection control.