What Is CMS?
CMS is the federal agency within the U.S. Department of Health and Human Services that administers Medicare, jointly administers Medicaid and CHIP with the states, and oversees the Health Insurance Marketplaces and HIPAA administrative simplification.
CMS
Also known as: Centers for Medicare & Medicaid Services; Health Care Financing Administration (former name)
CMS is the federal agency within the U.S. Department of Health and Human Services that administers Medicare, jointly administers Medicaid and CHIP with the states, and oversees the Health Insurance Marketplaces and HIPAA administrative simplification.
Definition
The Centers for Medicare & Medicaid Services, headquartered in Baltimore, is the largest single payer of healthcare in the United States, covering roughly 160 million Americans across Medicare, Medicaid, CHIP, and Marketplace plans. CMS publishes the Medicare Physician Fee Schedule (MPFS), the Hospital Outpatient Prospective Payment System (OPPS) APC rates, the MS-DRG inpatient rates, and the HCPCS Level II code set. It contracts with Medicare Administrative Contractors (MACs) to process Part A/B claims and oversees the National Correct Coding Initiative (NCCI).
Example
When a physician submits a claim for CPT 99213 to Medicare Part B, the claim routes to the regional MAC (such as Noridian for Jurisdiction E or Novitas for Jurisdiction H), is adjudicated against MPFS rates and NCCI edits published by CMS, and the resulting ERA reflects CMS-approved CARC and RARC denial codes.
Common Misconceptions
CMS is not the same as Medicare — Medicare is one program CMS administers. CMS does not directly process commercial-payer claims, but its rules (HCPCS codes, NCCI edits, place-of-service codes) are adopted by virtually every commercial payer.
Practical Application
Billing teams must monitor CMS regulatory updates published annually (the MPFS Final Rule each November, the OPPS Final Rule each November, and the IPPS Final Rule each August) because rate changes flow through to Medicare Advantage plans and many commercial contracts that reference Medicare RBRVS.
Related Terms
Medicare Part A/B/C/D
Medicare is divided into four parts: Part A covers hospital inpatient, SNF, hospice, and home health; Part B covers physician services and outpatient care; Part C (Medicare Advantage) is private plans replacing A and B; Part D covers prescription drugs.
Read definition arrow_forwardMedicaid
Medicaid is a joint federal-state program established under Title XIX of the Social Security Act that provides health coverage to eligible low-income individuals, with each state administering its own program under federal minimum requirements.
Read definition arrow_forwardMAC (Medicare Administrative Contractor)
A Medicare Administrative Contractor is a private organization that contracts with CMS to process Medicare Part A and Part B claims (or DME claims) within a defined geographic jurisdiction, applying CMS coverage rules and publishing local coverage determinations.
Read definition arrow_forwardMedicare Advantage
Medicare Advantage (Part C) is private health-plan coverage that replaces Original Medicare Parts A and B, offered by insurers under contract with CMS, typically as HMO or PPO products with provider networks, prior-authorization, and capitated risk-adjusted CMS payments.
Read definition arrow_forwardLCD / NCD (Local & National Coverage Determinations)
An NCD is a nationwide CMS coverage policy specifying whether Medicare will cover a service; an LCD is a coverage policy issued by a Medicare Administrative Contractor (MAC) for its jurisdiction when no NCD applies, defining medical necessity criteria and covered diagnosis codes.
Read definition arrow_forwardWhere This Applies on MedPrecision
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