Which Insurance Pays First When You Have Both Medicare and Medicaid

Medicare is primary when you have both programs

When you are covered by both Medicare and Medicaid, Medicare pays first on your medical bills. Medicaid then pays what Medicare does not cover, up to the limits Medicaid sets in your state. This order is set by federal law and does not change based on which program you signed up for first or which one you use more often.

The reason Medicare goes first is that it is considered your primary insurance. Think of it as the first payer — it processes your claim and pays its share. Medicaid steps in as the secondary payer only after Medicare has made its decision. This matters because it affects how much you owe out of pocket and which program's rules explore to your care.

People who have both programs are sometimes called "dual may be able to access" or "Medicare-Medicaid beneficiaries." You may have landed here because you may have access to for both — perhaps you turned 65 and kept your Medicaid coverage, or your income dropped low enough to may have access to for Medicaid while you were already on Medicare. Either way, the payment order stays the same.

Key Takeaways

Medicare always pays first on your medical bills when you have both programs, and Medicaid pays second on what Medicare leaves unpaid.
Your provider sends the bill to Medicare first; Medicare processes it and sends an explanation of benefits to you and your provider.
After Medicare pays, your provider can then bill Medicaid for the remaining balance, but only up to what Medicaid covers in your state.
You may still owe a copay, coinsurance, or deductible depending on the service and which program's rules explore.
Some states offer special Medicare-Medicaid plans (called D-SNPs) that coordinate both programs and may lower your out-of-pocket costs.

How the payment process works step by step

When you see a doctor or go to the hospital, the provider's office will bill Medicare first. They submit your claim to Medicare along with your Medicare number and details about the service. Medicare reviews the claim against its rules, decides what it will pay, and sends an explanation of benefits to both you and your provider.

Once Medicare has paid its share, your provider can then send the remaining bill to Medicaid. Medicaid looks at what Medicare paid and what is left over. If Medicaid covers that service in your state, it pays its portion — but only up to the amount Medicaid allows. Medicaid will not pay more than Medicare paid if Medicare's rate was lower.

After both programs have paid, you may still owe money. This could be a copay that Medicare requires, a coinsurance amount (a percentage of the cost), or a deductible. The amount depends on the type of service and which program's rules explore. Your provider's billing office should be able to tell you what you owe after both programs have processed the claim.

What you might still owe out of pocket

Having both Medicare and Medicaid does not mean you pay nothing. Medicare has its own copays and coinsurance amounts — for example, you may owe $20 for a doctor visit or 20 percent of the cost of an outpatient procedure. Medicaid in your state may also have copays, though many states waive copays for people on both programs.

The key is that Medicaid can pay your Medicare copays and coinsurance if your state's Medicaid program covers that service. This is called "cost-sharing information." However, Medicaid will not pay more than the amount Medicare allows, and it will not pay for services Medicare does not cover at all. Your state's Medicaid rules determine what it will help pay for.

If you use a provider who does not accept Medicare or Medicaid, neither program will pay, and you will owe the full bill. This is why it is important to check that your doctor and hospital accept both programs before you schedule care.

Special plans that coordinate Medicare and Medicaid

Some people with both Medicare and Medicaid can join a D-SNP (Dual may be able to access Special Needs Plan). These are Medicare Advantage plans designed specifically for people on both programs. A D-SNP coordinates your Medicare and Medicaid coverage in one plan, which can make it simpler to understand what you owe and where to get care.

D-SNPs are not available everywhere, and not all states offer them. Your state's Medicaid program must have an agreement with the insurance company offering the plan. If a D-SNP is available where you live, you can join during the annual enrollment period (October 15 to December 7 each year). You do not have to join a D-SNP — you can stay on Original Medicare and Medicaid separately if you prefer.

The advantage of a D-SNP is that it often includes extra benefits that neither Original Medicare nor Medicaid alone would cover, such as dental, vision, or hearing services. It may also lower your copays or eliminate them entirely. The trade-off is that you must use doctors and hospitals in the plan's network, and you may need prior approval for some services.

How to tell your providers which insurance is primary

When you register at a doctor's office or hospital, you will be asked for your insurance information. Always list Medicare first and Medicaid second. Give them both your Medicare card and your Medicaid card. The provider's billing staff will use this information to bill in the correct order.

If a provider bills Medicaid first by mistake, contact their billing office and ask them to correct it. Explain that Medicare is your primary insurance and must be billed first. If they continue to bill in the wrong order, you can report it to your state Medicaid office or to Medicare's customer service line at 1-800-MEDICARE.

Keep copies of both your Medicare card and Medicaid card with you when you go to appointments. If you lose either card, contact Medicare at 1-800-MEDICARE or your state Medicaid office right away to request a replacement. You need both cards to may support your claims are processed correctly.

What happens if you lose one of your programs

If you lose Medicare coverage, Medicaid becomes your primary insurance. This is rare — Medicare coverage does not end unless you ask for it or move out of the United States. However, if you lose Medicaid coverage, Medicare remains your primary insurance, and you will be responsible for Medicare's copays and coinsurance.

If your income increases and you no longer may have access to for Medicaid, you should look into whether you may have access to for a Medicare Savings Program (MSP) in your state. An MSP can help pay your Medicare premiums, copays, and deductibles if your income is slightly above the Medicaid limit. Each state runs its own MSP with different income limits, so contact your state Medicaid office to learn what is available.

If you lose Medicaid and do not may have access to for an MSP, you will owe all of Medicare's cost-sharing amounts yourself. This can add up quickly, especially if you have ongoing medical needs. Review your coverage each year during Medicare's annual enrollment period to understand what you will owe.

Questions to ask your doctor or insurance company

Before you have a procedure or start a new medication, ask your provider: "Will this be covered by Medicare or Medicaid, and what will I owe?" This helps you understand your costs upfront. Also ask: "Do you accept both Medicare and Medicaid?" Some providers accept only one program.

If you are thinking about joining a D-SNP, ask your current doctor whether they are in that plan's network. You can also call the plan directly to confirm which doctors and hospitals are included. Ask about copays for the services you use most often, such as doctor visits or prescription medications.

If you receive a bill you do not understand, call the provider's billing office and ask them to explain which program paid and why you owe the amount shown. Ask for an itemized bill that shows what Medicare paid, what Medicaid paid, and what you owe. This makes it easier to spot errors.

Frequently Asked Questions

Can I choose to have Medicaid pay first instead of Medicare?

No. Federal law requires Medicare to be primary when you have both programs. This order cannot be changed, even if you request it. The order is the same for all people with dual coverage, regardless of which program they signed up for first.

Will Medicaid pay my Medicare premiums?

Yes, if you may have access to for a Medicare Savings Program (MSP) in your state. An MSP can pay your Medicare Part B premium and sometimes your Part A premium as well. Income limits vary by state, so contact your state Medicaid office to see if you may have access to.

What if Medicare denies a claim — will Medicaid still pay?

Medicaid may pay even if Medicare denies the claim, but only if Medicaid covers the service. Medicaid has its own rules separate from Medicare's, so a service Medicare does not cover might still be covered by Medicaid. Contact Medicaid directly if Medicare denies your claim.

Do I need to do anything special to use both programs?

No. Once you are enrolled in both Medicare and Medicaid, the programs coordinate automatically. Just make sure your providers have both your Medicare and Medicaid information at every appointment. If you join a D-SNP, you will need to follow that plan's rules for which doctors to see.

What if I move to a different state?

Your Medicare coverage moves with you, but your Medicaid coverage does not. You will need to explore for Medicaid in your new state. Contact your new state's Medicaid office as soon as you move to start the process. Until your new Medicaid coverage begins, Medicare will be your only insurance.

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.