Modifier AS: Appropriate Use
Modifier AS: Non-physician Assisting at Surgery
Medicare has established the AS modifier to report Physician Assistant (PA), Nurse Practitioner (NP), or Clinical Nurse Specialist (CNS) services for assistant-at-surgery, non-team member. Therefore, for Medicare reporting purposes and as directed by a commercial third-party payor, to indicate PA, NP, or CNS services for assistant-at-surgery, ‘AS’ would be appended to the usual procedure number instead of one of the CPT modifiers. The provider must accept the assignment. Medicare allows 85% of the 16% for the assistant at surgery services provided by a PA, NP, or CNS.
When multiple procedure codes are billed for a surgical session and only some of the codes are eligible for assistant surgeon reimbursement, only the eligible codes will be reimbursed. The assistant surgeon must report the same codes as the surgeon. An exception to this is when the surgeon bills a global code (e.g. maternity care). In that case, the assistant at surgery must bill the specific surgery-only code (e.g. delivery only).
Additional Billing Information
- A Medical Doctor (MD) or Doctor of Osteopathic Medicine (DO) should not submit the ‘AS’ modifier. This modifier is only valid for use by non-physician practitioners (NPP) when billing under their own provider number.
- Medicare will deny the service as un-processable when the MD/DO modifiers (80, 81, or 82) are submitted on the same line of service as the AS modifier.
CPTs and Modifiers © Copyright 2021 American Medical Association
If you are still not sure and need help in medical billing for your practice, you can always contact us. E2E Medical Billing Services has an experienced billing and coding team that uses exact modifiers to bring accurate insurance reimbursement. To know more about our medical billing services call us at 888-552-1290 or write to us at [email protected]