Ambulatory surgery centers (ASC) emerged in the United States in response to the twin pressures of rising healthcare costs and growing patient demand for more accessible, efficient care. In recent history, these facilities have undergone major growth. In the late 1960s, healthcare professionals and policymakers began advocating for outpatient surgical alternatives to traditional hospital-based procedures, which often required extended stays and imposed significant financial burdens. To combat these difficulties, in February 1970, Drs. Wallace Reed and John Ford opened the first freestanding ambulatory surgery center—known as Surgicenter—in Phoenix, Arizona. On its inaugural day, five physicians performed five procedures, four of which required general anesthesia, marking an important shift toward care delivered outside the hospital setting.
In the early 1970s, regulatory and professional organizations began to define standards to support the growth of the sector. This marked a key step in the history of ambulatory surgery centers, signifying formalization and greater acceptance. In 1971, the American Medical Association formally endorsed the concept of outpatient surgery under appropriate anesthesia for selected patients, and in 1973, the American Society of Anesthesiologists released some of the earliest guidelines for ambulatory surgical facilities. By the mid‑1970s, the number of such centers had grown steadily—from a handful in the early 1970s to approximately 42 by 1975. Recognition and oversight followed, as ASCs began to receive accreditation from organizations such as the Joint Commission and the Accreditation Association for Ambulatory Health Care.
The 1980s marked a turning point in the financial viability and proliferation of ASCs. In 1982, Medicare began approving payments for procedures performed in ASCs—initially covering about 200 procedures and grouping them into payment categories based on cost surveys. By 1987, Medicare had expanded its reimbursement list to include over 1,500 specific procedures, and by 1988, the number of ASCs in the United States reached 1,000.
The expansion continued through the 1990s and into the 21st century. In 1995, Medicare broadened its list of approved procedures to more than 2,000, and by 2003, ASCs accounted for more than 2,400 covered procedures across over 4,000 facilities. The federal recognition of the ASC sector gained institutional reinforcement in 2008 when the major national associations—the Federated Ambulatory Surgery Association and the American Association of Ambulatory Surgery Centers—merged to form the Ambulatory Surgery Center Association. As of 2011, there were over 5,300 ASCs in the U.S., performing more than 23 million surgeries annually, with Medicare approving more than 3,500 procedures for performance in these centers.
Not all states regulate ASCs in the same way. In Delaware, ambulatory surgery centers are regulated as “Free‑Standing Surgical Centers” (FSSCs). These facilities require an annual license, with initial licensure costing $250 and renewal at $150. They must also ensure that patients undergo a comprehensive medical history and physical assessment within 30 days before surgery. Unlike some states, Delaware does not mandate written hospital transfer agreements nor impose state-level price transparency rules on these centers. In addition, developers wishing to establish new freestanding surgery centers must obtain approval through the state’s Certificate of Public Review process.
Technological innovations—especially in anesthesia and minimally invasive techniques—together with physician ownership structures, cost savings, and streamlined operational models, have all contributed to the sustained growth of ASCs, making them integral to modern healthcare delivery. Safety and clear benefits to patients have also fueled the upward trajectory of ambulatory surgery centers across the history of this sector.
