Ambulatory Surgical Services


An "outpatient center for surgical services" is a clinic, infirmary, or other institution or organization "that is specifically designed and operated to provide surgical services to patients not requiring hospitalization and that may include recovery care beds" (50-5-101(44), Montana Code Annotated [MCA]). According to 50-5-101(49), MCA, a "recovery care bed" means, except as provided in 50-5-235, "a bed occupied for less than 24 hours by a patient recovering from surgery or other treatment."

Patients suitable for ambulatory surgery may require some form of anesthesia, as well as professional post-operative observation, but have surgery and are released in the same day. Ambulatory surgery may be provided in distinct, freestanding facilities as described above, in hospital areas used only for ambulatory surgery, or in hospital areas serving both ambulatory and inpatient surgery patients.

Freestanding ambulatory surgical facilities or centers are also known as surgicenters, same-day surgery centers, or outpatient surgery centers. These facilities may be restricted to one surgical specialty or they may serve multiple specialties.

Hospital services for ambulatory surgical care are reviewable under Certificate of Need (CON), as stated in 50-5-301(1)(i), MCA. These services, as well as freestanding ambulatory surgical facilities, are reviewed based on the current CON dollar thresholds and other appropriate criteria, as outlined in the MCA and the Administrative Rules of Montana (ARM).


  • Ambulatory surgical services should be available and accessible to all Montanans who are appropriate for such services. These services should serve as a more cost-efficient and convenient alternative for receiving surgical services.


  • To promote the development of ambulatory surgical services where such services would provide clients quality care in an accessible and affordable manner.

Certificate of Need Guidelines
As outlined in 50-5-304, MCA, any applicant seeking to provide ambulatory surgical services should address the review criteria in its CON application, including an evaluation of the proposal with the guidelines established in this section. The review criteria consider consistency with this State Health Care Facilities Plan, but also allow consideration of additional data and information.

  • An application for a CON to establish or expand an ambulatory surgical facility in a county with less than 20,000 population will be approved only when a need exists in the health planning region proposed to be served, according to the need methodology described below. The applicant does not need to assume the entire health planning region as its proposed service area. An applicant must demonstrate, using this methodology, that existing ambulatory surgical capacity (in freestanding facilities and hospitals combined) is not adequate to handle the number of ambulatory surgical procedures projected three years from the anticipated opening date of the suites. The Table below uses the Year 2020 as the target year for need projection.
  • An ambulatory surgical facility proposing expansion must be utilizing its own capacity at 80% or greater of a five-day (eight hours per day), 52-week year.
  • Proposed ambulatory surgical facilities should be no smaller than two operating suites.
  • Ambulatory surgical facilities must adhere to the Code of Federal Regulation (CFR) requirements, including operating time limits and transfer arrangements.
  • An applicant for a CON to provide ambulatory surgical services must demonstrate that the proposed facility will provide at least 600 surgical procedures per suite per year, and that the proposed facility will be financially viable within two years of initiation.
  • An applicant must show support from local physicians who anticipate utilizing the facility.
  • An applicant must provide evidence there is a formal process in place for providing follow up services to patients requiring them (i.e., home health care, outpatient care).
  • An applicant must ensure they will become certified to participate in Medicare and Medicaid and will provide some free care.

Need Methodology for Ambulatory Surgical Services
Projections shown in the Table below indicate the number of ambulatory surgical procedures and suites needed in each health planning region projected three years from the current year. These calculations will be revised annually. "Future suites needed" includes those suites that are presently in operation.

The projected number of ambulatory surgical procedures and suites needed in each health planning region shall be determined by applying the following formula:

  • Determine the surgery rate per 1,000 population in the region using the most recent data collected by DPHHS on total ambulatory surgeries performed (hospital outpatient surgeries + ambulatory surgeries) and the population for each region for the same year (U.S. Bureau of the Census or NPA Data Services, Inc.).
  • Apply the surgery rate to the regional population projections three years from the current year (from the U.S. Bureau of Census or NPA Data Services, Inc.) to determine the projected number of total surgeries.
  • Determine the number of surgeries to be performed on an outpatient basis by multiplying the projected number of total surgeries by the statewide percentage of total surgeries which are outpatient for that year. This percentage will be revised annually and will always be rounded to the nearest five percent.
  • Determine the number of future operating suite hours needed by multiplying the projected number of outpatient surgeries, by 1.5 hours. (This number represents the average hours per operating suite visit which has been assumed to be the maximum allowable operating time of 1.5 hours as stated in the CFR.)
  • Determine the number of operating suites needed three years from the current year by dividing the number of future operating suite hours by the operating suite capacity. The operating suite capacity is defined as 1,664 available service hours per operating suite per year. This number is based on 80 percent utilization of an operating suite that is available 40 hours per week, 52 weeks per year (80% x 40 x 52 = 1,664). The number of future suites needed includes those suites presently operational.

This component projects the need for ambulatory surgical suites on a regional basis for each of Montana's five health planning regions. While it is understood that health planning regions may not be identical to a facility's service area or proposed service area, these projections can serve as a guideline for the development of services within each region. This methodology can be applied to other service areas as defined by an applicant, as the need may arise. However, DPHHS will use historical hospital and ambulatory surgical facility patient origin data to determine if a proposed service area is realistic.

These projections are for all types of ambulatory surgical services. DPHHS will not make detailed estimates of the need for ambulatory surgical suites in each possible specialty area. An applicant proposing a specialty ambulatory surgical facility must provide detailed information addressing the need for the particular specialty.

DPHHS collects data annually on services provided by both hospitals and ambulatory surgical services. The distribution of the Annual Survey of Ambulatory Surgical Facilities began in 1993.

ASC Need Projections for 2019

List of Ambulatory Surgical Centers