When you have both Medicare and Medicaid, they coordinate to cover your medical costs

If you are enrolled in both Medicare and Medicaid, the two programs work together to pay your medical bills. Medicare is your federal health insurance based on age or disability. Medicaid is a state program for people with low income. When you have both — a situation called "dual may be able to access" — Medicaid typically pays the costs that Medicare does not cover, such as copayments, coinsurance, and deductibles. This coordination means you may have lower out-of-pocket costs than someone with Medicare alone.

The order in which they pay matters. Medicare is always the primary payer, meaning it pays first on any covered service. Medicaid then steps in as the secondary payer and covers what Medicare left behind. This happens automatically once both programs know you are enrolled in each one. You do not have to choose which one pays or submit claims twice — the providers handle the coordination.

Key Takeaways

  • Medicare pays first on all covered services, and Medicaid covers the remaining costs you would otherwise owe out of pocket.
  • You must be enrolled in both programs separately; having one does not automatically enroll you in the other.
  • Your state Medicaid program sets its own rules about which services it will cover after Medicare, so coverage varies by state.
  • Dual may be able to access individuals often pay little to nothing for doctor visits, hospital stays, and prescription drugs because Medicaid fills in the gaps.
  • You will receive a Medicare card and a Medicaid card (or number) and should carry both when you see a provider.

How the payment order works in practice

When you go to the doctor or hospital, the provider bills Medicare first. Medicare reviews the claim and pays its share based on what the service costs and what Medicare covers. If there is a copayment, coinsurance, or deductible, you would normally owe that amount. Instead, the claim then goes to Medicaid, which pays that remaining balance on your behalf.

For example, suppose you have a doctor visit that costs $150. Medicare allows $120 for that visit and pays 80 percent of it, which is $96. You would normally owe the remaining $24 as coinsurance. With Medicaid as your secondary payer, Medicaid receives the claim and pays that $24. You owe nothing. This happens for most services covered by both programs — office visits, hospital stays, lab work, and imaging.

The coordination is not always perfect. Some providers may not know you have Medicaid or may not bill it correctly. If you receive a bill you think Medicaid should have paid, contact your Medicaid office. You can also ask the provider's billing department to resubmit the claim to Medicaid.

What Medicaid covers after Medicare when you are dual may be able to access

Medicaid covers the gaps in Medicare, but what counts as a "gap" depends on your state. All states cover Medicare copayments and coinsurance. Most states also cover Medicare deductibles — the amount you must pay before Medicare starts paying. Some states cover prescription drug costs that Medicare Part D does not fully cover.

Medicaid does not cover services that Medicare does not cover, even if your state Medicaid program would normally cover them for non-Medicare people. For instance, if Medicare does not cover dental care, Medicaid will not pay for your dental care either, even if your state Medicaid covers dental for other low-income adults. The rule is: Medicaid fills gaps in Medicare coverage, not gaps in what Medicare chooses to cover.

Some services fall outside both programs entirely. Long-term care in a nursing home is one example. Medicare covers only the first 100 days under specific conditions. After that, you pay out of pocket until your resources are spent down. Then Medicaid may cover nursing home care, but rules vary by state. Ask your state Medicaid office what it covers for long-term care in your situation.

How to enroll in both programs

You enroll in Medicare and Medicaid separately. Medicare enrollment happens through Social Security or the Centers for Medicare & Medicaid Services (CMS). If you are 65 or older, you become may be able to access for Medicare automatically when you turn 65 if you have worked and paid Medicare taxes. You must sign up during your Initial Enrollment Period, which is the three months before, the month of, and the three months after your 65th birthday. If you miss that window, you may face a permanent penalty on your premiums.

Medicaid enrollment is handled by your state. Each state has its own income limits, resource limits, and process process. Some states use online portals, others require you to explore in person or by mail. To find your state Medicaid office, search "[your state] Medicaid" or call 211 for a referral. When you explore, tell them you are also on Medicare so they can coordinate the two programs correctly in their system.

Once you are enrolled in both, the programs should communicate automatically. However, it is worth confirming. Call your state Medicaid office and ask them to verify that they have your Medicare information on file. This ensures that when claims come in, Medicaid knows to pay as secondary.

Your costs when you have both Medicare and Medicaid

Most people with both Medicare and Medicaid pay very little out of pocket. Medicaid covers the copayments and coinsurance that Medicare does not pay, so a doctor visit or hospital stay typically costs you nothing. Prescription drugs through Medicare Part D may also be covered with little or no cost, depending on your state Medicaid program.

However, you may still owe money in certain situations. If you see a provider who does not accept Medicare or Medicaid, neither program will pay, and you are responsible for the full bill. If a service is not covered by either program, you owe the cost. Some states also charge small copayments for certain services even when Medicaid is paying, though many states waive these for dual may be able to access individuals.

Your Medicare Part B premium (the monthly charge for doctor and outpatient coverage) is usually paid by Medicaid if your income is low enough. Your Part D premium (for prescription drug coverage) may also be covered. Ask your state Medicaid office which premiums they pay in your case.

What happens if you move to a different state

If you move, your Medicare coverage continues without interruption — Medicare is federal and works the same everywhere. Your Medicaid coverage does not automatically transfer. You must explore for Medicaid in your new state, and the income limits, resource limits, and covered services may be different.

Before you move, contact your new state's Medicaid office and ask what you need to do. Some states allow you to explore before you move. Others require you to explore after you arrive. Find out the income and resource limits in your new state so you know whether you will still be covered. If your new state has stricter limits, you might lose Medicaid coverage even though you had it in your old state.

During the transition, keep both your Medicare and old Medicaid cards until your new state confirms your new Medicaid enrollment. If there is a gap in coverage, you could face unexpected bills.

Keeping track of your coverage and fixing problems

You should receive a Medicare card from Social Security and a Medicaid card or number from your state. Carry both when you see a provider. Tell each provider that you have both programs so they know to bill in the correct order.

Check your Medicare Summary Notice (the statement Medicare sends you) and your Medicaid Explanation of Benefits (the statement your state sends you) to make sure claims are being paid correctly. If you see a charge you do not recognize or a service that should have been covered, contact the program that should have paid it. Keep copies of any bills or notices in case you need to dispute a charge.

If you move, change your address with both Medicare and your state Medicaid office so you continue to receive notices. If your income changes, report it to Medicaid because it may affect your coverage. If you turn 65 and become newly may be able to access for Medicare while already on Medicaid, contact both programs to make sure they coordinate properly.

Questions to ask your doctor and your programs

Before a procedure or hospital stay, ask your provider's billing department whether they accept both Medicare and Medicaid. Ask them to confirm they have both your Medicare number and your Medicaid number. Ask whether the service is covered by Medicare and, if so, what your out-of-pocket cost will be after Medicaid pays.

Call your state Medicaid office and ask: Does your state cover Medicare deductibles? Does it cover prescription drugs that Medicare Part D does not fully cover? What is the process if I receive a bill I think Medicaid should have paid? If you are thinking about moving, ask what you need to do to enroll in Medicaid in your new state.

Frequently Asked Questions

Do I have to enroll in both Medicare and Medicaid, or does one automatically enroll me in the other?

You must enroll in each program separately. Enrolling in Medicare does not automatically enroll you in Medicaid, and vice versa. You become may be able to access for Medicare at 65 if you have worked and paid Medicare taxes, but you must sign up during your Initial Enrollment Period. Medicaid is a separate process through your state, with its own income and resource limits.

What if a provider bills only Medicare and forgets to bill Medicaid?

Contact your provider's billing department and ask them to submit the claim to Medicaid as well. You can also contact your state Medicaid office and ask them to follow up on the claim. Keep a copy of the bill and the Medicare payment so you have proof of what was paid. Do not pay the bill yourself until you have given Medicaid a chance to pay.

If I have both Medicare and Medicaid, do I still need to choose a Medicare Advantage plan or a Medigap policy?

No. Medicaid already covers the gaps that Medigap would cover, so buying a Medigap policy would be redundant and a waste of money. Medicare Advantage plans are also usually not recommended for dual may be able to access people because Medicaid already handles the secondary payment. Stick with Original Medicare (Part A and Part B) and let Medicaid coordinate as your secondary payer.

What if my state Medicaid program does not cover something that Medicare does not cover?

Medicaid covers gaps in Medicare, not gaps in what Medicare chooses to cover. If Medicare does not cover a service, Medicaid will not cover it either, even if your state would normally cover it for non-Medicare people. For example, if Medicare does not cover dental care, your state Medicaid will not pay for your dental care. You would need to pay out of pocket or find a low-cost dental clinic.

Can I lose my Medicaid coverage if my income goes up slightly?

Yes. Medicaid has income limits that vary by state. If your income rises above your state's limit, you may lose coverage. Report any income changes to your state Medicaid office right away. Some states have programs for people who lose Medicaid due to income, such as Medicaid Buy-In programs that let you keep coverage by paying a small premium. Ask your Medicaid office what options are available if your income changes.