HCPCS Modifier AS
Submit HCPCS modifier AS to identify the services of a physician assistant, nurse practitioner, or clinical nurse specialist for assistant at surgery.
Guidelines and Instructions
- Submit HCPCS modifier AS to identify the services of a surgical assistant
- Supporting documentation describing the medical necessity for an assistant must be submitted with the claim for services that have Asst Surg Indicator 0 in the MPFSDB
In addition, the following documentation is required in the medical record when the surgery is performed in a teaching hospital:
- A statement that no qualified resident was available to perform the service
- A statement indicating that exceptional medical circumstances exist
- A statement indicating the primary surgeon has an across-the-board policy of never involving residents in the preoperative, operative or postoperative care of his or her patients
To determine whether the services of an assistant may be submitted to Medicare with CPT modifier AS, refer to the Medicare Physician Fee Schedule database (MPFSDB):
- Access the database directly from the CMS website
- Select Physician Fee Schedule Search from the left area of the web page
- Screen defaults to current year. Under "Type of Information," select Payment Policy Indicators, then Next
- On the "Select Field Options" screen, select Next
- Enter the procedure code and select All Modifiers, then click Submit
- Refer to the column heading "Asst Surg"
Indicator 0 = Payment restriction for assistants at surgery applies to this procedure. Supporting documentation describing the medical necessity for an assistant must be submitted with the claim.
Indicator 1 = Statutory payment restriction for assistants as surgery applies to this procedure. Assistants at surgery will not be paid.
- Indicator 2 = Payment restriction for assistants at surgery does not apply to this procedure. Assistants at surgery may be paid.
- Indicator 9 = Concept does not apply (the most likely explanation is that the procedure is not a surgery)
- CMS Pub. 100-04, Chapter 12, Sections 20.4.3, 40.8.D, 100.1.7 (teaching hospital requirements) (PDF, 1.10 MB)
- CMS Pub. 100-04, Chapter 23 (PDF, 817 KB) in the Addendum at the end of the chapter