Whether you need supplemental coverage depends on which Medicaid program you're in and what Medicare covers

If you have both Medicaid and Medicare, you generally do not need a separate Medicare supplemental policy — Medicaid already fills gaps that supplemental insurance would cover. However, the answer changes based on your specific situation: your age, income, which state you live in, and whether you're in a Medicaid managed care plan or traditional Medicaid.

The key distinction is that Medicaid acts as your supplemental coverage when you have both programs. It pays Medicare copayments, coinsurance, and deductibles that Medicare doesn't cover. Buying a Medigap policy (the formal name for Medicare supplemental insurance) on top of Medicaid would be redundant and wasteful — you'd be paying premiums for coverage Medicaid already provides.

Key Takeaways

  • Medicaid covers Medicare's copayments, deductibles, and coinsurance, so a separate Medigap policy would duplicate coverage you already have.
  • If you're in a Medicaid managed care plan, your coverage works differently than traditional Medicaid, and you should confirm with your plan what it covers.
  • Some states do not cover all of Medicare's cost-sharing, so your out-of-pocket costs may vary depending on where you live.
  • If you lose Medicaid may be able to access, you may have a limited window to buy Medigap without waiting periods or higher premiums.

How Medicaid covers what Medicare doesn't

Medicare has built-in costs: a deductible before coverage starts, copayments for each visit or service, and coinsurance (a percentage of the cost you pay). For someone on a limited income, these add up quickly. When you have both Medicare and Medicaid, Medicaid is designed to pay these gaps — it's called being "dual may be able to access."

Medicaid will pay the Part B deductible (currently $240 per year, though this changes annually), copayments for doctor visits, and coinsurance for hospital stays and other services. In most states, it also covers the Part A deductible (the hospital deductible, which is much larger). This is exactly what Medigap policies do, which is why buying both would be paying twice for the same protection.

What changes if you're in a managed care plan

Many states require or allow Medicaid recipients to join managed care plans — these are insurance companies that contract with Medicaid to provide coverage. If you're in a Medicaid managed care plan, your coverage structure is different from traditional Medicaid, and you need to check your specific plan's documents.

Some managed care plans cover all of Medicare's cost-sharing; others cover most but not all. A few states have plans that cover less. You should contact your plan directly and ask: "What Medicare copayments and deductibles do you cover?" The answer determines whether you have any gaps left unpaid. If your plan has gaps, Medigap might make sense, though availability varies by state and plan type.

State-by-state variation in what Medicaid covers

Not every state covers every Medicare cost-sharing expense. Most cover the Part B deductible and copayments, but some do not cover the full Part A deductible or certain coinsurance amounts. A few states have more limited programs that cover less.

You can find what your state covers by contacting your state Medicaid office or by asking your Medicaid caseworker. The Centers for Medicare & Medicaid Services (CMS) also publishes state-by-state summaries, though these can be technical. The simplest route is to call your state's Medicaid customer service line and ask directly: "What Medicare costs does my Medicaid cover?"

When you might still consider Medigap

In rare cases, if your state's Medicaid program has significant gaps in Medicare cost-sharing coverage, buying a Medigap policy could reduce your out-of-pocket costs. This is uncommon, but it happens in a handful of states. Before buying, confirm with your state Medicaid program exactly what it does and does not cover, then compare that against what a Medigap plan would add.

Another scenario: if you're about to lose Medicaid may be able to access (for example, because your income will increase), you may have a limited window to buy Medigap without underwriting or waiting periods. This is called a "may provide issue" period, and it typically lasts 60 days after you lose Medicaid. If you know you're losing coverage, ask your Medicaid caseworker about this window before it closes.

What happens if you lose Medicaid

If your Medicaid coverage ends — whether because your income increased, you moved to a different state, or your may be able to access changed — you lose the gap coverage Medicaid provided. At that point, you would need either a Medigap policy or a Medicare Advantage plan to cover Medicare's copayments and deductibles.

The timing matters. If you buy Medigap within 60 days of losing Medicaid, insurance companies must sell you a policy without medical underwriting and without waiting periods. If you wait longer, they can deny you or charge more based on your health history. Mark the date you lose Medicaid and start shopping for Medigap or Medicare Advantage within that 60-day window if you think you'll need it.

Medicare Advantage as an alternative

Some people with both Medicare and Medicaid use Medicare Advantage plans instead of traditional Medicare plus Medigap. Medicare Advantage plans often have lower or zero copayments and may include dental or vision coverage. However, they typically require you to use doctors and hospitals in their network, and they have annual out-of-pocket limits.

If you're considering Medicare Advantage, check whether your state's Medicaid program will still cover any remaining cost-sharing that Medicare Advantage doesn't. Some states do; others don't. You should also verify that your current doctors participate in the plan's network. Call the plan directly and ask for a list of providers in your area.

How to confirm your coverage

The safest approach is to contact both your Medicare and Medicaid programs and ask them directly what you're covered for. For Medicare, call 1-800-MEDICARE or log into your account at Medicare.gov. For Medicaid, call your state's Medicaid customer service line (the number is on your Medicaid card or available through your state's website).

Ask Medicaid specifically: "What Medicare deductibles, copayments, and coinsurance do I have to pay out of pocket?" Write down the answer and keep it. If you're in a managed care plan, ask your plan the same question. This takes 15 minutes and prevents confusion later.

Frequently Asked Questions

Can I have both Medicaid and a Medigap policy at the same time?

Legally, yes — nothing prevents you from buying both. Practically, it's wasteful because Medicaid already covers what Medigap would pay. You'd be paying Medigap premiums for duplicate coverage. The only exception is if your state's Medicaid program has documented gaps in Medicare cost-sharing that Medigap would fill.

If I'm in a Medicare Advantage plan, do I still need Medicaid to cover copayments?

It depends on your state and plan. Some states' Medicaid programs will cover Medicare Advantage copayments; others won't. Check with your state Medicaid office and your Medicare Advantage plan to confirm what you'll owe out of pocket. If Medicaid won't cover the copayments, you may want to switch back to traditional Medicare with Medicaid as your gap coverage.

What if my Medicaid gets cancelled — do I have time to buy Medigap?

Yes, but only for 60 days. If you lose Medicaid, you have a 60-day "may provide issue" period to buy any Medigap plan without medical underwriting or waiting periods. After 60 days, insurers can deny you or charge more. Mark the date you lose coverage and start shopping within that window if you'll need supplemental coverage.

Does Medicaid cover Medicare Part D (prescription drugs)?

No. Medicaid does not cover Part D copayments or deductibles. However, if you're low-income and on both programs, you may be may be able to access for the Part D Low-Income Subsidy (LIS), which reduces your drug costs. Contact your state Medicaid office or call 1-800-MEDICARE to learn whether you may have access to.

What if I move to a different state — does my coverage stay the same?

No. Medicaid rules vary significantly by state, so what your old state covered may differ from what your new state covers. When you move, contact your new state's Medicaid office and ask what Medicare costs they cover. You may also need to re-enroll in a new Medicaid plan or managed care option.