CMS
CMS — the Centers for Medicare & Medicaid Services — is the federal agency that administers Medicare, Medicaid, and related health-insurance programs and sets many of the billing rules the US system follows.
Updated
The Centers for Medicare & Medicaid Services (CMS) is the agency within the US Department of Health and Human Services that runs Medicare, partners with states on Medicaid, and administers other programs including the Children's Health Insurance Program (CHIP) and the Health Insurance Marketplace. It issues the regulations, manuals, and code-set standards that govern how providers bill those programs.
For billing, CMS publishes the Medicare Claims Processing Manual and Medicare Learning Network guidance, maintains the Healthcare Common Procedure Coding System (HCPCS) and the place-of-service code set, contracts with Medicare Administrative Contractors, and defines the transactions providers and clearinghouses exchange with Medicare.
In practice
CMS guidance is the reference point for Medicare billing and a model many commercial and Medicaid payers follow. Because its rules are published and versioned, a billing question about a federal program usually resolves to a CMS manual section or transmittal rather than to informal interpretation.
Commonly confused with
- Medicare Administrative Contractor: CMS is the federal agency that sets policy; a Medicare Administrative Contractor (MAC) is a private company CMS pays to process claims and administer a Medicare region.
- Medicaid: CMS provides federal oversight and funding for Medicaid, but each state runs its own Medicaid program within federal rules, so Medicaid specifics are state-by-state.