Incident-to: Auxiliary Staff vs. NPQPs
What’s the difference between Auxiliary Staff and NPQPs?
When discussing incident-to services, it’s important to consider two distinct categories. The first involves Non-Physician Qualified Providers (NPQPs)—such as Advanced Practice Nurses, Physician Assistants, and Certified Nurse Specialists—whose services may be billed under their own NPI or under a supervising physician, depending on the circumstances. The second category pertains to auxiliary personnel, whose roles and billing limitations differ significantly. Understanding the nuances between these two groups is essential for accurate and compliant billing.
Who are Auxiliary Personnel?
(Not an all-inclusive list)
- Medical Assistants (MAs)
- Licensed Practical Nurses (LPNs)
- Registered Nurses (RNs)
- Registered Dietician (RDs)
- Genetic Counselor (GCs)
- Other unlicensed or licensed clinical staff
What services may auxiliary staff perform?
That’s going to depend on the scope of their licensure (or not) and training.
Examples:
- Injections (e.g., B12, flu shots)
- Vital signs collection
- Wound care (basic dressing changes)
- Suture removal
- Patient education (if part of the established plan of care)
- Breathing treatments (e.g., nebulizer administration)
These can be billed under the NPQP or physician’s NPI if all incident-to requirements are met.
What level of supervision is required for incident to?
Auxiliary staff performing services billable by the supervising physician or NPQP must meet incident-to requirements, one of which is direct supervision.
Direct Supervision means:
- The supervising provider must be physically present in the office suite and immediately available (not necessarily in the same room)
- Think…feet in the suite!
Own Statutory Benefit Category
Depending on their scope of practice, certain auxiliary personnel may be authorized to report specific services independently. For instance, a credentialed Registered Dietitian (RD) can directly bill for Medical Nutrition Therapy (MNT). Similarly, Genetic Counselors may report genetic counseling services. In such cases, CPT may assign unique codes that are designated exclusively for use by these qualified professionals.
Other auxiliary personnel, such as medical assistants, are not credentialed and therefore cannot bill for services independently. If they perform services that fall under a distinct Medicare benefit category, those services are not eligible to be billed as incident-to.
These services are excluded from incident-to billing because they are covered under their own statutory benefit category and have separate supervision and billing rules.
Statutory Benefit Category Examples:
- Diagnostic tests (e.g., X-rays, EKGs, lab tests)
- Radiation therapy
- Durable Medical Equipment (DME) (e.g., walkers, oxygen tanks)
- Medical Nutrition Therapy
- Genetic Counseling
- Screening mammograms and Pap smears
- Bone mass measurements
- CRNA services
- Vaccines like pneumococcal or hepatitis B
Incident-to vs. Specific Benefit Category Table
| Service Type | Can Be Billed Incident-To? | Reason |
| B12 Injection by MA | ✅ Yes | Part of physician’s plan of care |
| EKG by MA | ❌ No | Diagnostic test with its own benefit category |
| Dressing change | ✅ Yes | Routine office procedure |
| DME (e.g., walker) | ❌ No | Covered under DME benefit category |
| Screening mammogram | ❌ No | Preventive service with its own category |
| Patient education on diabetes | ✅ Yes | If part of established plan of care |
A common misconception is that if a service isn’t reimbursable when performed by auxiliary staff, it can simply be billed as incident-to under the physician. However, as we’ve explored, incident-to billing involves specific criteria and limitations. Each service or procedure may have its own unique guidance, making it essential to evaluate compliance on a case-by-case basis.
If you need additional information, please feel free to reach out. Your departmental compliance liaison can be found on our Meet the Team page, or you can email me, at [email protected].
Resources:
CMS.gov – Incident to page
Novitas Solutions – Incident to E/M page
AAPC – 7 Incident to Billing Requirements
MSHBC – Incident to Billing Basics
MSHBC – Incident to still on OIG Radar