Medicare is a federally administered insurance program offered to those who are 65 years of age and older.  Those younger than 65 may qualify if they have disabilities such as end stage renal failure.   The Centers for Medicare and Medicaid Services (CMS) administers the program, and the Social Security Administration is responsible for determining eligibility of participants, processing payments, and assuring compliance to the regulations.  Information on Medicare and how Medicare works can be found at or at


The different parts of the Medicare Program

Medicare has four parts (A, B, C, D).  Part A is Hospital Insurance.  In the past, Medicare allowed Hospital-Based PAs to bill under Part A through the hospital cost reports, which has changed (Medicare Claims Processing Manual Chapter 12, Section 120.1).  If your hospital is billing for your services under part A contact MAPA or the AAPA at

Medicare Part B is medical insurance.  Medicare now requires physicians and NPPs (non physician providers including PAs) to submit claims for their services under part B (except for administrative responsibilities).  Therefore, it is important to understand the regulations set forth by CMS under part B.   Medicare Part C, or Advantage plans, is another way for beneficiaries to receive their Part A, B and D benefits.  Part D covers prescriptions drugs.

According to CMS “Medicare Part B (Medical Insurance) helps cover doctors' services and outpatient care.  It also covers other medical services that Part A doesn't cover, such as physical and occupational therapists, and home health care. Part B helps pay for these covered services and supplies when they are medically necessary.”    (


Medicare And PAs

Medicare will reimburse for PA services under part B for services in doctor’s offices, hospitals, nursing facilities, and ambulatory surgery centers.  Services must be in the scope of practice for the NPP (PA) and be allowed under state law.   PAs are allowed to bill all levels of evaluation and management codes, consultations, initial hospital visits, hospital discharges, mental health services, and other services.  The American Academy of Physician Assistants  and the Maryland Academy of Physician Assistantswork together to promote legislative and regulatory changes that limit reimbursement for PAs.


Payment by Medicare

 Medicare require services provided by PAs to be reimbursed at 85 percent of the physician fee schedule unless specific billing exceptions apply, e.g. incident to and shared billing  (see explanations of these services in the frequently asked questions section).   PAs must enroll in Medicare and receive an NPI (National Provider Identifier) and must bill at the full physician rate.   The PA’s NPI number will alert CMS to pay at 85 percent.  To enroll see the section on enrolling and credentialing.