MedPac in its March 2020 report to Congress made a series of recommendations on ASCs and documented several statistics on the industry.
MedPac analyzed 3,277 single-specialty surgery centers by specialty in 2018. Here are the number of centers by specialty:
Gastroenterology: 1,071
Ophthalmology: 1,046
Pain management: 612
Dermatology: 197
Urology: 127
Podiatry: 87
Cardiology: 55
Orthopedics: 33
Respiratory: 26
OB-GYN: 14
Neurology: 4