Physician Assistants (PAs) enroll in Medicare Part B as non-physician practitioners and can bill independently for most services within their scope of practice. Like NPs, PAs can also bill under incident-to arrangements — but the supervision requirements are stricter for PAs than for NPs in most states.
Enrollment basics
PAs enroll via the CMS-855I or PECOS online. Requirements:
- Graduation from an ARC-PA accredited PA program
- NCCPA certification (current Physician Assistant-Certified [PA-C] credential)
- State licensure as a PA
- Collaborating or supervising physician arrangement (required in most states, though this is evolving)
NPI: Type 1 NPI required. For group billing, also need CMS-855R to reassign benefits.
Billing rates and arrangements
Independent billing under your NPI: PAs bill Medicare at 85% of the physician fee schedule, same as NPs.
Incident-to billing: PAs can bill incident-to at 100% of the physician fee schedule under the same conditions as NPs — established patients, physician-established plan of care, physician physically present in the suite.
⚠️ Risk flag: States are expanding PA practice authority, but Medicare’s incident-to rules are federal and don’t change based on state scope-of-practice expansions. Even if your state allows independent PA practice, Medicare incident-to billing still requires the supervising physician to be present in the suite.
Collaborative agreements
Many states require a collaborative practice agreement with a physician for PA licensure. Medicare doesn’t require you to submit this agreement during enrollment, but you must have one in place if your state requires it — failing to maintain one while billing Medicare can create overpayment exposure.
Key applications
- CMS-855I — individual enrollment
- CMS-855R — reassignment to group (if applicable)
- CMS-855O — ordering/referring (if you prescribe or order tests)
Timeline
30–60 days via PECOS. Verify your NCCPA certification is current before enrolling — CMS will verify at enrollment and at revalidation.
Ask Mae if you have questions about your specific state’s PA practice authority and how it interacts with Medicare billing.