The Centers for Medicare & Medicaid Services (CMS) is a federal agency within the U.S. Department of Health and Human Services. It administers Medicare and works with states on Medicaid and the Children's Health Insurance Program (CHIP).
What CMS manages
- The federal Medicare program and rules for Medicare health and drug plans.
- Federal Medicaid and CHIP policy, oversight, and partnerships with state and territory agencies.
- The Health Insurance Marketplace and HealthCare.gov.
- Standards and oversight involving participating health plans, providers, facilities, and certain health care transactions.
What CMS does not usually handle directly
- Social Security processes most applications for Medicare Part A and Part B.
- State or territory Medicaid agencies receive applications and make individual Medicaid eligibility decisions.
- Medicare Advantage and Part D companies handle plan-specific enrollment, formularies, networks, claims, and member services under Medicare rules.
- CMS is not a substitute for a doctor, insurance plan, state benefits office, or personalized legal advice.
Official public service websites
- Medicare.gov — Medicare coverage, plans, costs, and enrollment information
- Medicaid.gov — federal Medicaid and CHIP information
- HealthCare.gov — Health Insurance Marketplace
- CMS.gov — agency policy, provider, plan, data, and program resources
Finding the correct office
People with Medicare should normally begin at Medicare.gov or 1-800-MEDICARE. People applying for Medicaid or CHIP should use the official state or territory agency. Medicare Part A and Part B enrollment often begins with the Social Security Administration.
CMS and Social Security have different IRMAA roles
CMS establishes the annual Part B and Part D adjustment amounts. Social Security uses IRS information to make individual IRMAA determinations and handles SSA-44 life-changing-event requests. Contact the agency named in the notice rather than sending an SSA-44 to CMS.
See how to request a Part D redetermination.
CMS sets the federal rules for Part D plan coverage determinations, grievances, and appeals. The enrollee files an individual level 1 redetermination with the Medicare drug plan named in the denial notice, not with CMS headquarters. An unfavorable plan decision may then move to the independent review levels described in the notice.
Medicare drug coverage determinations and appeals
Official sources
Related resources
- Sign up for Medicare
- Review Original Medicare claims
- Understand the Medicare Summary Notice
- Join a Medicare drug plan
- Apply for Medicaid
- Renew Medicaid or CHIP coverage
- Social Security Administration
- Apply for a Medicare Savings Program
- Administration for Community Living and SHIP
- Appeal an Original Medicare claim decision
- Medicare redetermination
- U.S. Department of Health and Human Services
- Request a Medicaid fair hearing
- Appeal a Medicare Advantage plan decision
- Medicare grievance
- Important Message from Medicare
- Fast appeal when SNF, home health, hospice, or CORF services are ending
- Fast appeal after a hospital changes inpatient status to observation
- Choose the correct IRMAA review route