About Nurses as Assistants at Surgery

Question: What is a first assistant nurse? Does a nurse need to be a first assist to bill when assisting the physician in surgery?

Answer: A first assistant nurse in Texas is a licensed registered nurse who has completed the nurse first assistant education program and either (1) is recognized by the Texas Board of Nursing as an advanced practice registered nurse (APRN) and qualified by education, training, or experience to perform the tasks involved in perioperative nursing, or (2) is certified in perioperative nursing.

Nurse practitioners (NPs), clinical nurse specialists (CNSs), and certified nurse-midwives (CNMs) are types of APRNs under Board of Nursing rules; Medicare refers to these by their separate designations and has different requirements for them serving as first assistant, or assistant-at-surgery.

Billing for a First Assistant

Billing and credentialing vary among commercial carriers. Check with the carriers you contract with for their specific policies.

Medicare is strict on what services are included in a global surgery package. Medicare will pay for a nurse practitioner, clinical nurse specialist, or nurse-midwife as assistant-at-surgery when the procedure is covered for an assistant under the Medicare physician fee schedule (MPFS). Medicare does not pay separately for certified first assistants.

In addition, Medicare will pay for an assistant-at-surgery who is a physician or a physician assistant (PA).

No other type of assistant, such as surgical technician, a first surgical assistant, or scrub nurse, is payable by Medicare or billable to the patient.

An assistant at surgery must actively assist the physician in charge of a case in performing a surgical procedure and furnish more than just ancillary services.


  1. Billing Medicare for APRNs assistant-at-surgery services

    Medicare will pay covered NP or CNS assistant-at-surgery services at 80% of the lesser of the actual charge or 85% of the 16% that a physician is paid for assistant-at-surgery services under the MPFS. Since physicians are paid at 16% of the surgical payment amount under the MPFS, the actual payment amount that NPs and CNSs receive for assistant-at-surgery services is 13.6% of the amount paid to physicians. Only the AS modifier must be reported on the claim form when a NP or CNS bills assistant-at-surgery services.

    To bill Medicare, a nurse practitioner must have obtained Medicare billing privileges as a nurse for the first time either:
    1. On or after Jan. 1, 2003, and
      (a) Be certified as a nurse practitioner by a recognized national certifying body that has established standards for nurse practitioners; and
      (b) Have a master’s degree in nursing or a doctor of nursing practice degree;
    2. Before Jan. 1, 2003, and meets the standard in (1)(a) above; or

    3. Before Jan 1, 2001.

    The following organizations are recognized national certifying bodies for nurse practitioners and clinical nurse specialists:

    • American Academy of Nurse Practitioners;
    • American Nurses Credentialing Center;
    • National Certification Corporation for Obstetric, Gynecologic and Neonatal Nursing Specialties;
    • Pediatric Nursing Certification Board (previously the National Certification Board of Pediatric Nurse Practitioners and Nurses);
    • Oncology Nurses Certification Corporation;
    • AACN Certification Corporation; and
    • National Board on Certification of Hospice and Palliative Nurses.

    A clinical nurse specialist must have a master’s degree in nursing or a doctor of nursing practice degree and must be certified as a clinical nurse specialist by one of the above listed organizations.

    Payment for certified nurse-midwife services is made directly to the nurse-midwife; when CNMs bill for their services under specialty code 42, billing does not have to flow through a physician or facility unless the CNM reassigns benefits to another billing entity. A certified nurse midwife must be certified by an accrediting body approved by the U.S. Department of Education and the American College of Nurse-Midwives or the American Midwifery Certification Board.

    For more information regarding APRNs, refer to:

    • Medicare Program Integrity Manual, Chapter 10,;;
    • Medicare Claims Processing Manual, Chapter 12, 120; 120.1; 130.1
    • Medicare Benefit Policy Manual, Chapter 15, 200
  2. Billing others for assistant-at-surgery services

    For assistant-at-surgery services performed by physicians, the fee schedule amount equals 16% of the amount otherwise applicable for the surgical payment. Services are billed with physician modifiers 80, 81, or 82. Payment for state-licensed physician assistants is the same as for NPs and CNSs.

    For more information regarding physicians and PAs, refer to:

    • Medicare Program Integrity Manual, Chapter 10,
    • Medicare Claims Processing Manual, Chapter 12, 20.4.3; 110.2

Last Updated On

June 22, 2022

Originally Published On

June 22, 2022

Related Content

Billing and Collections | Coding