Description
Assistant at surgery services by non-physician providers (PA, NP, or CNS), are reimbursed at 85 percent of 16 percent (i.e., 13.6 percent) of the Medicare Physician Fee Schedule Data Base amount. Modifier "AS" is used for assistant at surgery services provided by a physician's assistant (PA), nurse practitioner (NP), or clinical nurse specialist (CNS). Assistant at surgery claims billed by non-physician practitioners without modifier AS, will be corrected, adding modifier AS, repricing the claim.
Affected Code(s)
CPT code range 10021 through 69990 with assistant at surgery indicator of “0” or “2”
Applicable Policy References
1. Social Security Act (SSA), Title XVIII- Health Insurance for the Aged and Disabled, Section 1862(a)(1)(A)- Exclusions from Coverage and Medicare as a Secondary Payer
2. Social Security Act, Title XVIII- Health Insurance for the Aged and Disabled, Section 1833(e)- Payment of Benefits
3. Social Security Act, Title XVIII- Health Insurance for the Aged and Disabled, Section 1833(a)(1)(O)- Payment of Benefits
4. 42 Code of Federal Regulations (CFR) §405.929- Post-Payment Review
5. 42 Code of Federal Regulations (CFR) §405.930- Failure to Respond to Additional Documentation Request
6. 42 Code of Federal Regulations (CFR) §405.980- Reopening of Initial Determinations, Redeterminations, Reconsiderations, Decisions, and Reviews, (b)- Timeframes and Requirements for Reopening Initial Determinations and Redeterminations Initiated by a Contractor; and (c)- Timeframes and Requirements for Reopening Initial Determinations and Redeterminations Requested by a Party
7. 42 Code of Federal Regulations (CFR) §405.986- Good Cause for Reopening
8. 42 Code of Federal Regulations (CFR) §414.4- Payment for Part B Medical and Other Medical Services
9. 42 Code of Federal Regulations (CFR) §414.40- Coding and Ancillary Policies
10. Medicare Benefit Policy Manual Chapter 15 §200 - Nurse Practitioner (NP) Services
11. Medicare Claims Processing Manual, Chapter 12- Physician/ Nonphysician Practitioner, §20.4.3
12. Medicare Claims Processing Manual Chapter 12- Physician Practitioner Billing, § 100.1.7.B.
13. Medicare Claims Processing Manual, Chapter 12- Physician/ Nonphysician Practitioner, §110.2 - Limitations for Assistant-at-Surgery Services Furnished by Physician Assistants
14. Medicare Claims Processing Manual, Chapter 12- Physician/ Nonphysician Practitioner, §120 - Nurse Practitioner (NP) and Clinical Nurse Specialist (CNS) Services
15. Medicare Program Integrity Manual, Chapter 3- Verifying Potential Errors and Taking Corrective Actions, §§3.1- 3.6.6
16. American Medical Association. “Modifiers Used with Surgical Procedures”, CPT Assistant, Fall 1992, page 15.
17. American Medical Association. "A Closer Look at the Use of Surgical Modifiers" CPT Assistant, March 1996: 8.
18. American Medical Association Current Procedural Terminology (CPT) Codebook
19. Medicare Physician Fee Schedule (MPFS) Physician Fee Schedule | CMS
20. AMA CPT Codebook