Ambulatory surgery refers to surgical or invasive diagnostic procedures performed by qualified providers in ambulatory or dedicated surgical suites with pre-procedural and immediate post-procedural care on the same day, or observation admissions without hospitalization (Patient Selection Criteria for Ambulatory [Same Day] Surgery VHA Handbook).

Medically Necessary:

The use of an outpatient or ambulatory surgery center (ASC) facility is considered medically necessary when criteria (A) and (B) are met:

1. The procedure itself must first be determined to be medically necessary.
2. The procedure itself must be of a level of complexity that it may not be performed in a less intensive setting such as a medical office, but also not so complex as to require post-operative recovery in an inpatient facility.

Factors contributing to this complexity, which would require an ASC rather than an office setting, include any one of the following:

1. Need for anesthesia or sedation beyond topical anesthesia, digital block, or local anesthesia with concomitant need for monitoring of physiologic parameters beyond intermittent checks of vital signs.
2. Need for recovery period of significant duration beyond the capacity of a physician's office.
3. The individual has specific medical conditions which require specific monitoring, medications or a more prolonged recovery period OR comorbid conditions which place the individual at greater risk of complications from the procedure or the anesthesia.  In general, individuals treated in an ASC are classified as Category I or II by the American Society of Anesthesiologists classification.
4. The individual has specific factors (including extremes of age) which preclude an office procedure.

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

Specific procedure and diagnosis coding does not apply to this document.

While hospitals continue to provide essential services for serious illness, much health care activity takes place in the ambulatory setting.  Surgical practices have been transformed so that more than half of all surgery in the United States is performed on an ambulatory basis ( Patient Selection Criteria for Ambulatory [Same Day] Surgery VHA Handbook).  Ambulatory (or outpatient) surgery provides an efficient and flexible means to provide many surgical and therapeutic procedures without requiring an inpatient hospital admission.

Government Agency, Medical Society, and Other Authoritative Publications:

1. Medicare Claims Processing Manual. Chapter 14 - Ambulatory Surgical Centers. (Rev. 2020, 08-06-10). Available at: https://www.cms.gov/manuals/downloads/clm104c14.pdf. Accessed on September 08, 2011.
2. American Medical Association Amended Core Principles (Office-based Surgery Principles) presented to AMA House of Delegates 1/03. Available at: http://www.ama-assn.org/ama1/pub/upload/mm/370/obscoreprinciples.pdf. Accessed on September 3, 2010.
3. Guidelines for Office-Based Anesthesia, American Society of Anesthesiologists (Approved by the ASA House of Delegates on October 13, 1999, and last affirmed on October 21, 2009). Available at:  http://www.asahq.org/For-Members/Clinical-Information/Standards-Guidelines-and-Statements.aspx. Accessed on September 8, 2011.
4. Patient Selection Criteria for Ambulatory (Same Day) Surgery VHA Handbook 1102.5 Appendix A dated May 20, 2003. Available at: http://www1.va.gov/vhapublications/ViewPublication.asp?pub_ID=414. Accessed on September 8, 2011.

Ambulatory or Outpatient Surgery Center Procedures
Ambulatory Surgery Center Procedures
Outpatient Surgery Center Procedures