Centers for Medicare & Medicaid Services (CMS)

The Centers for Medicare & Medicaid Services is the agency of the U.S. Department of Health and Human Services responsible for the federal government's major health coverage programs. In its own description, "CMS is the federal agency that provides health coverage to more than 160 million through Medicare, Medicaid, the Children's Health Insurance Program, and the Health Insurance Marketplace." The agency writes the regulations for those programs, pays or oversees the payment of claims, and publishes the consumer sites Medicare.gov and HealthCare.gov.

The name is spelled with an ampersand on the agency's own materials and is also written with "and"; both refer to the same agency. It should not be confused with the Social Security Administration, which is a separate, independent agency even though it handles much of Medicare enrollment.

What CMS runs directly. Medicare and Medicaid were signed into law on July 30, 1965. Medicare is a federal program, and CMS runs it: Part A hospital insurance, Part B medical insurance, and the contracts with private companies that offer Medicare Advantage and Part D drug plans. Each year it announces the next year's Part A and Part B premiums and deductibles, so any Medicare premium or deductible figure is good for one year only.

What it oversees. Medicaid and the Children's Health Insurance Program are run by each state under federal rules. CMS approves state plans and waivers and administers the federal share, which is why the rules for who qualifies, and what is covered, differ by state. Medicaid.gov, also run by CMS, calls Medicaid "the primary payer across the nation for long-term care services."

The Marketplace. CMS operates the federal Health Insurance Marketplace through HealthCare.gov for states that do not run their own exchange.

Where the Social Security Administration comes in. A great deal of what people think of as Medicare business goes through SSA. Medicare.gov's sign-up page sends people who need to enroll to SSA, online or at a local office, rather than to CMS. SSA also determines the income-related monthly adjustment amount added to Part B and Part D premiums for higher-income beneficiaries. CMS sets the program's rules and premiums; SSA handles much of the enrollment and the income determinations.

1. Congress writes the programs into law; CMS issues the regulations and guidance that put them into effect.

2. CMS publishes each year's Medicare costs and contracts with the private plans that offer Medicare Advantage and Part D coverage.

3. States run Medicaid and CHIP under plans that CMS approves.

4. The public deals with CMS mostly through its websites, Medicare.gov for Medicare plan comparison and coverage rules and HealthCare.gov for Marketplace coverage.

5. Enrollment and income-related premium decisions for Medicare mostly go through SSA.

Pros

• One agency sets Medicare's core rules for the whole country.
• Its consumer sites, Medicare.gov and HealthCare.gov, carry official plan comparison tools.
• Its yearly announcements are the authoritative source for Medicare's premiums and deductibles.

Cons

• Responsibility is split with the Social Security Administration and with the states, so a person may have to deal with more than one agency.
• Medicaid rules vary by state even though CMS oversees the program.
• Costs change every year, so a figure from a past announcement is quickly out of date.