When You Have Both Medicare and Medicaid: Which One Pays First

Medicare is primary when you have both programs

If you are enrolled in both Medicare and Medicaid, Medicare pays first on your medical bills. Medicaid then pays what Medicare does not cover — copayments, coinsurance, and deductibles — up to the limits your state sets. This order is set by federal law and does not change based on your income, age, or reason for having both programs.

The person who manages this coordination is you, or your doctor's billing office. When you go to a provider, you give them both your Medicare card and your Medicaid card. The provider bills Medicare first. Once Medicare processes the claim and sends its payment, the provider then bills Medicaid for the remainder. If Medicaid covers it under your state's rules, they pay their share.

The practical result is that you usually pay nothing out of pocket for services both programs cover. But the details matter: what Medicaid will pay depends on your state, your Medicaid category, and whether the provider is enrolled in both programs.

Key Takeaways

Medicare always bills first; Medicaid pays second and covers what Medicare leaves behind, such as copays and deductibles.
You must give both cards to your provider every time you receive care, or the billing will not coordinate correctly.
What Medicaid covers as a secondary payer varies by state and by which Medicaid program you are in (QMB, SLMB, or full Medicaid).
Some providers do not accept Medicaid, which means Medicaid cannot pay their share even if Medicare does.
If a provider bills you instead of billing the programs, you can ask them to rebill with both cards, or contact your state Medicaid office for help.

Why you might have both Medicare and Medicaid

You can have both programs if your income and assets fall below your state's Medicaid limit, even though you also may have access to for Medicare. This happens most often if you are over 65 with low income, or if you are on Social Security Disability Insurance (SSDI) and your income stays low after two years of receiving benefits.

Some people are automatically enrolled in both. If you receive Supplemental Security Income (SSI) in addition to SSDI, your state usually enrolls you in Medicaid without you having to ask. If you are 65 or older and your income is very low, you may be enrolled in a may have access to Medicare Beneficiary (QMB) program, which is a type of Medicaid that exists only to help Medicare beneficiaries pay their premiums and cost-sharing.

Others must request Medicaid enrollment separately. Even if you are on Medicare, you can explore for Medicaid through your state if your income qualifies. The income limits vary widely by state — some allow up to 100 percent of the federal poverty level, others up to 200 percent or more.

The three Medicaid programs that work with Medicare

Not all Medicaid is the same when paired with Medicare. Your state may place you in one of three categories, and each pays differently.

may have access to Medicare Beneficiary (QMB) is the narrowest. QMB covers only what Medicare does not: your Medicare Part B premium, your Part A and Part B deductibles, and your coinsurance. It does not cover services Medicare does not cover. Income limits are strict — usually around 100 percent of the federal poverty level, which is roughly $1,400 per month for a single person in 2024, though this varies by state.

Specified Low-Income Medicare Beneficiary (SLMB) is slightly broader. SLMB pays your Medicare Part B premium only, not your deductibles or coinsurance. Income limits are higher than QMB, usually around 120 percent of poverty. If you do not may have access to for QMB but your income is still low, your state may place you in SLMB instead.

Full Medicaid means you are enrolled in your state's regular Medicaid program in addition to Medicare. Full Medicaid covers everything your state's Medicaid program covers — which can include dental, vision, hearing aids, and long-term care — after Medicare pays its share. Income and asset limits are higher than QMB or SLMB, and they vary significantly by state.

How billing works when both programs are involved

The process starts when you give your provider both your Medicare card and your Medicaid card. Write your Medicaid number on the intake form, and tell the front desk staff you have both programs. Many providers' computer systems are set up to coordinate this automatically, but some are not.

The provider bills Medicare first using your Medicare claim information. Medicare processes the claim, applies your deductible if you have not met it yet, and sends payment to the provider. Medicare also sends you an Explanation of Benefits (EOB) showing what they paid and what they did not.

The provider then uses that Medicare EOB to bill Medicaid. Medicaid receives the claim, sees what Medicare paid, and pays its portion according to your state's rules. If you are in QMB, Medicaid pays your copay and coinsurance. If you are in SLMB, Medicaid may pay nothing because SLMB only covers the Part B premium, which is paid directly to Medicare, not to the provider.

The entire process usually takes four to eight weeks. During that time, you should not receive a bill from the provider. If you do, contact the provider's billing office and ask them to hold the bill until both programs have processed the claim.

What happens if a provider does not accept Medicaid

Some doctors, hospitals, and specialists accept Medicare but not Medicaid. When this happens, Medicare will still pay its share, but Medicaid cannot pay theirs — even if your Medicaid program would normally cover the service.

You will owe the difference between what Medicare pays and what the provider charges. If the provider is a Medicare-participating provider, they have agreed to accept Medicare's payment as payment in full for most services, so your out-of-pocket cost is limited to your copay or coinsurance. But if they are a non-participating provider, they can charge you more.

Before you receive care from a provider, ask whether they accept Medicaid. You can also call your state Medicaid office or check your state's Medicaid provider directory online. If a provider does not accept Medicaid, you have the choice to go elsewhere or to pay out of pocket.

What to do if billing does not coordinate correctly

Sometimes a provider bills only Medicare and forgets to bill Medicaid. Sometimes they bill Medicaid first by mistake. Sometimes they bill you directly instead of billing either program. In any of these cases, you can take action.

If you receive a bill from the provider, contact their billing office and explain that you have both Medicare and Medicaid, and that Medicare should have been billed first. Ask them to rebill with both programs. Provide your Medicare number and your Medicaid number, and ask for a written confirmation that they have submitted the corrected claim.

If the provider's billing office does not respond or refuses to rebill, contact your state Medicaid office. Medicaid has the authority to investigate billing problems and can pressure providers to bill correctly. Your state Medicaid office can also tell you whether the provider is required to accept Medicaid in your state.

Keep copies of all bills, Explanations of Benefits from both Medicare and Medicaid, and any correspondence with the provider. If a debt collector contacts you about a bill that should have been covered, you can dispute it by providing proof that you submitted both insurance cards and that the provider failed to bill correctly.

Frequently Asked Questions

Do I have to pay a premium for Medicaid if I also have Medicare?

No. If you are in QMB or SLMB, Medicaid pays your Medicare Part B premium for you, so you pay nothing. If you are in full Medicaid, you do not pay a Medicaid premium either. You may still pay a Medicare Part D premium if you are enrolled in a prescription drug plan, but that is separate from Medicaid.

What if I have a Medicare Advantage plan instead of Original Medicare?

Medicaid still pays second. Your Medicare Advantage plan is your primary payer, and Medicaid covers what the plan does not. However, some Medicare Advantage plans have different cost-sharing than Original Medicare, so what Medicaid pays may differ. Always give both your Medicare Advantage card and your Medicaid card to your provider.

Can Medicaid refuse to pay because Medicare already paid?

Yes, in some cases. If you are in SLMB, Medicaid only pays your Part B premium and does not pay copays or coinsurance. If you are in QMB, Medicaid should pay your cost-sharing, but some states have limits on how much they will pay per service or per year. Check your state's Medicaid handbook to see what your specific program covers.

What if I lose Medicaid but keep Medicare?

You will be responsible for all copays, coinsurance, and deductibles that Medicaid was covering. You may want to purchase a Medigap policy (supplemental insurance) to cover these costs instead. Medigap policies are sold by private insurance companies and help pay what Medicare does not cover.

How do I know which Medicaid program I am in?

Your Medicaid card or your state Medicaid office will tell you. Call the number on your Medicaid card and ask what program you are enrolled in — QMB, SLMB, or full Medicaid. You can also log into your state's Medicaid portal online if your state offers one. Knowing your program type helps you understand what Medicaid will and will not pay.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.