Nurse Practitioners (NPs) are non-physician practitioners who can enroll directly in Medicare Part B and bill independently for a wide range of services. NPs can also bill under incident-to arrangements in certain settings — a distinction that affects reimbursement rates and documentation requirements significantly.
Enrollment basics
NPs enroll using the CMS-855I (Individual Provider Enrollment Application) or via PECOS online. You must hold:
- A Master’s or Doctoral degree in nursing from an accredited program
- Current RN licensure in the state where you practice
- National certification as a Nurse Practitioner (AANP, ANCC, or specialty board)
- State licensure or recognition as an NP with prescriptive authority
NPI: You need a Type 1 NPI (individual). If your practice is billing under a group NPI, the organization needs a Type 2 NPI and you’ll need to file a CMS-855R to reassign your benefits to the group.
Enrollment sequence
- Obtain or verify your Type 1 NPI at NPPES (if you don’t have one)
- Enroll via PECOS or paper CMS-855I
- If billing under a group: complete CMS-855R to reassign benefits to the group’s Type 2 NPI
- Credential separately with any Medicare Advantage plans
Independent billing vs. incident-to
Independent billing (under your NPI): NPs bill Medicare directly at 85% of the physician fee schedule. All services must be within your scope of practice under state law.
Incident-to billing: NPs can bill incident-to a physician at 100% of the physician fee schedule when:
- The service is rendered in a physician office or clinic (not hospital outpatient)
- A physician established the plan of care and the NP is carrying out that plan
- The supervising physician is present in the office suite (not necessarily in the room)
- The patient is an established patient, not a new patient
⚠️ Risk flag: Incident-to billing is frequently audited. The most common error: billing incident-to for new patients (not allowed), for services the physician hasn’t established a plan for, or when the supervising physician is not physically present in the suite. One audit can trigger retroactive denials for an entire billing period.
Key applications
- CMS-855I — individual enrollment (required)
- CMS-855R — reassignment of benefits (if billing under a group NPI)
- CMS-855O — if you order or refer items/services (required for prescribing)
Timeline
PECOS enrollment: 30–60 days. Ensure your state NP license and national certification are current before applying — expired credentials are the #1 cause of NP enrollment delays.
Ask Mae if you have questions about independent billing vs. incident-to, or if you need help with the enrollment sequence for your practice setting.