Generally, prior to being able to bill and receive payment from a federal health care program, such as Medicare or Medicaid, a health care provider or supplier must first enroll with that particular payer. The enrollment process is complex and time-consuming due to the significant amount of information required and scrutiny applied to that information. Once enrolled, the provider or supplier must maintain and update enrollment forms, as well as comply with various conditions of payment or participation. Failure to do so may result in revocation of billing privileges and/or termination from the program. This chapter of the AHLA Health Care Compliance Legal Issues Manual, written by partner Howard Young and associate Jacob Harper, focuses on the Medicare enrollment process and the authority under which the Centers for Medicare & Medicaid Services (CMS) levies Medicare billing revocations.