The Centers for Medicare and Medicaid Services runs both Medicare and Medicaid

The Centers for Medicare and Medicaid Services (CMS) is the federal agency inside the U.S. Department of Health and Human Services that operates Medicare, Medicaid, and the Children's Health Insurance Program (CHIP). If you receive Medicaid or are considering it, CMS is the organization setting the rules that your state's Medicaid program must follow.

CMS does not run Medicaid directly in your state. Instead, it sets national standards, provides federal funding, and oversees how each state administers its own program. Your state's Medicaid agency — often called the Department of Social Services or Department of Health Care Services, depending on where you live — handles the day-to-day work of processing applications, determining who qualifies, and managing benefits.

Understanding CMS's role matters because it explains why Medicaid rules vary by state, why some coverage decisions take time, and where to find official information when you have questions about your benefits.

Key Takeaways

  • CMS is a federal agency that sets the rules and provides funding for Medicaid, but your state runs the actual program.
  • Each state can design its own Medicaid program within CMS guidelines, which is why coverage and income limits differ across states.
  • CMS publishes official guidance, coverage policies, and state-by-state program details on its website at cms.gov.
  • If you have a dispute about a Medicaid decision, your state agency makes the initial ruling, but CMS oversees how fairly states follow federal law.

How CMS sets the rules your state Medicaid program must follow

CMS establishes minimum standards that every state's Medicaid program must meet. These standards cover who can receive Medicaid, what services must be covered, how much states can charge for care, and how quickly claims must be processed. States cannot go below these floors — they can only go above them.

For example, CMS requires that Medicaid cover certain services like hospital care, doctor visits, and emergency services in every state. But a state can choose to cover additional services like dental care or vision care if it wants to. A state can also set its income limit higher than the federal minimum, meaning more people would may have access to in that state than in another.

This is why two people with the same income and family size might may have access to for Medicaid in one state but not in another. CMS sets the floor; each state decides how much further to go.

Where to find official CMS information about Medicaid

CMS publishes information about Medicaid on its official website, cms.gov. The site includes state-by-state program details, coverage policies, and guidance for both people receiving Medicaid and the agencies that run it.

If you need to know what your specific state's Medicaid program covers or what the income limits are, you can find that information through CMS's state pages. However, for questions about your own case — whether you may have access to, what your benefits are, or why a claim was denied — you need to contact your state's Medicaid agency directly, not CMS.

CMS also maintains a resource called Medicaid.gov, which is separate from cms.gov and designed for people looking for Medicaid information in plain language. That site helps you find your state's Medicaid office and understand how the program works.

Why CMS oversight matters when you disagree with a Medicaid decision

Your state's Medicaid agency makes the first decision about whether you may have access to for benefits or whether a particular service is covered. If you disagree with that decision, you have the right to request a hearing through your state.

CMS does not overturn individual state decisions, but it does monitor whether states are following federal law. If a state is systematically denying people benefits they should receive, or if a state is not following CMS rules, CMS can investigate and require the state to fix the problem. CMS also has the power to reduce federal funding to a state that does not comply with Medicaid law.

This means CMS acts as a backstop to make sure states treat Medicaid applicants fairly, even though you will work with your state agency for your own case.

The difference between CMS and your state Medicaid agency

It is common to be confused about which agency to contact. Here is the practical difference: CMS writes the rules and provides the money; your state agency applies the rules to your situation.

If you have questions about whether you may have access to for Medicaid, whether a service is covered, or why your application was denied, contact your state Medicaid agency. If you want to understand the national rules that your state must follow, or if you believe your state is not following federal law, you can contact CMS — though CMS will usually direct you back to your state agency first.

Your state Medicaid agency's contact information should be on your Medicaid card, in any letters you receive about your benefits, or on your state's health department website.

How CMS funding works and why it affects your state's program

CMS distributes federal Medicaid money to states based on a formula that accounts for state population and income levels. States must contribute their own money as well — the federal government does not pay the entire cost. The federal share varies by state, typically ranging from 50 percent to 75 percent of total Medicaid spending.

This funding structure means that when CMS changes its rules or adds new requirements, it affects how much money states have to spend on other programs. It also means that if a state wants to expand Medicaid coverage beyond federal minimums, the state has to pay for part of that expansion itself.

Understanding this helps explain why some states expand Medicaid and others do not, and why coverage can change if a state faces budget pressure.

CMS programs beyond Medicaid

While this article focuses on Medicaid, CMS also runs Medicare (the federal health insurance program for people 65 and older and some younger people with disabilities) and CHIP (which covers children in families that earn too much for Medicaid but not enough to afford private insurance).

CMS also oversees quality standards for hospitals, nursing homes, and other health care providers. If you have a complaint about the quality of care at a facility, CMS may be involved in investigating that complaint.

All three programs — Medicare, Medicaid, and CHIP — operate under CMS oversight, though each has its own rules and funding structure.

Frequently Asked Questions

Can I contact CMS directly if I have a problem with my Medicaid benefits?

You can, but CMS will usually direct you to your state Medicaid agency first, since your state handles individual cases. Start with your state agency. If you believe your state is not following federal law, you can file a complaint with CMS, but have your state's response in writing first.

Does CMS approve or deny my Medicaid application?

No. Your state Medicaid agency approves or denies your application based on CMS rules. CMS sets the standards; your state applies them to your situation. You will receive your decision from your state, not from CMS.

Why does my state's Medicaid program look different from my neighbor's state?

CMS sets minimum standards, but each state can design its program within those standards. States choose different income limits, different covered services, and different rules about how to apply. This is why Medicaid varies so much from state to state.

What should I do if I think CMS or my state is breaking Medicaid rules?

Contact your state Medicaid agency first and ask for an explanation in writing. If you still believe a rule is being broken, you can file a complaint with CMS through its website or contact your state's Medicaid ombudsman, who investigates complaints about the program.

Is CMS the same as my state's Medicaid office?

No. CMS is the federal agency in Washington, D.C. Your state's Medicaid office is a state agency in your state capital or regional offices. They work together, but CMS does not handle individual cases.