A few words on a medical bill can change how safe your retirement budget feels: “You may owe.” With Original Medicare, it’s normal to be responsible for deductibles, copays, and coinsurance, and those costs can stack up quickly because there’s no yearly cap on what you pay out of pocket for your Part B services unless you add supplemental coverage.
That’s where Medigap comes in. Medigap (also called Medicare Supplement Insurance) is designed to limit your monetary share of Medicare approved medical costs. While Medigap plans help cover Medicare Part A copays, these Medigap plans are especially important to cover the 20% of costs not paid for by Medicare for Part B covered services. Medigap plans help make the true cost of Medicare in 2026 much more predictable, so you can focus on your health, not surprise bills.
What is Medigap?
Medigap is extra insurance you buy from a private insurance company to help pay your share of out-of-pocket costs in Original Medicare, like deductibles, coinsurance, and copayments.
A key rule: you generally must have Original Medicare (Part A and Part B) to buy Medigap. Medigap is meant to “supplement” Original Medicare, not replace it.
Why Medigap matters for retirement planning
Original Medicare can be excellent coverage, but it’s not the same as a typical employer plan. For example, Medicare.gov explains that Original Medicare Part B has no yearly out-of-pocket limit unless you have supplemental coverage such as Medigap.
For many people the goal is simple: reduce “financial surprises” and “protect your retirement savings” in the years when you’re living on a more fixed income and protecting retirement savings.
What is covered
Medigap plans are designed to help with cost-sharing gaps in Original Medicare. Therefore if Medicare Part A or Part B cover a service, Medigap plans will help cover those approved services too. These costs may include things like:
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Part A and Part B coinsurance/copayments
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Hospital deductibles and extended hospital days (depending on the plan)
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Skilled nursing facility coinsurance (depending on the plan)
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Foreign travel emergency coverage (in some plans)
The exact benefits depend on which standardized plan letter you choose.
What is not covered
Medigap is helpful, but it’s not “everything insurance.” Medicare.gov lists several common items Medigap generally doesn’t cover, such as long-term care, dental/vision, hearing aids, and private-duty nursing. As a reminder, if Medicare Part A and B don’t cover a service, then Medigap likely won’t cover it either.
Also important: Medigap plans sold after 2005 don’t include prescription drug coverage, so most people pair Medigap with a separate Part D drug plan if they want drug coverage.
The Letter Plans
One of the best things about Medigap is that it’s standardized. In most states, there are 10 Medigap plan types (letters A–D, F, G, and K–N). Policies with the same letter offer the same basic benefits no matter where you live or which company sells it, and price is often the main difference for the same letter plan across insurers.
A quick (and important) update: if you became newly eligible for Medicare on or after January 1, 2020, you generally can’t buy Medigap Plan C or Plan F.
When to enroll: the timing that can protect your options
Your most important window is your Medigap Open Enrollment Period. Under federal law, it lasts 6 months and starts the first month you have Part B and you’re 65 or older. During this time, you can generally buy a Medigap policy without medical underwriting. (Medicare)
Outside of that window, you may still be able to buy Medigap, but depending on your state and situation, you could face underwriting or fewer choices.
What Medigap typically costs (and why prices vary so much)
Two people can buy the same letter plan and pay very different premiums. Pricing depends on factors like where you live, the company, household discounts, tobacco status, and how the policy is priced.
Medicare’s official Medigap guide highlights three common pricing approaches insurers may use: community-rated, issue-age-rated, or attained-age-rated.
Bottom line: the plan letter tells you the benefits, but it does not tell you the price.
How to choose a Medigap plan
We recommend you first decide which letter fits you best. Once you have this finalized you can pick out the company you want to purchase the plan through (note: not all companies offer all plans) If you like predictable costs and broad provider access, here are practical filters that work well to identify your best Medigap plan letter:
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Budget vs. predictability: Higher premiums can mean fewer surprise bills later.
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Your health care “style”: Do you go to the doctor often, or only occasionally?
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Travel: Some plans include limited foreign travel emergency coverage.
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Future flexibility: Switching later isn’t always guaranteed without underwriting, so think long-term
How to choose a Medigap company
Medigap plans are offered by private companies. Because of guarantee issuance rules in most states, you will likely be with this company for the rest of your life to it’s important to select wisely. It is common for certain companies to artificially lower prices to lure you in to a plan, then increase prices once your guarantee issuance window goes away, and you are likely stuck with the higher premium. Therefore, we have a seven factor supplement company scorecard to identify the Tier 1 companies
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Financial Ratings
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Years in the Market
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History of Rate Hikes
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Customer Service
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Contract Pricing
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Loss Ratio
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Market Share
Medigap FAQ
Can I have Medigap and Medicare Advantage at the same time?
No. Medigap works with Original Medicare, not Medicare Advantage.
Does Medigap cover prescription drugs?
Generally no. Medigap plans sold after 2005 don’t include drug coverage, so most people add Part D if they want drug coverage.
What’s the best time to buy Medigap?
During your one-time 6-month Medigap Open Enrollment Period that starts when you’re 65+ and enrolled in Part B.
Are all Medigap Plan G policies the same?
Benefits are standardized by letter in most states, so Plan G benefits are the same across companies, but premiums can differ.
Why do people say Original Medicare can have “no limit”?
Because there’s no yearly out-of-pocket cap in Original Medicare for Part B unless you have supplemental coverage like Medigap.
Can everyone buy Plan F?
Not if you’re newly eligible for Medicare on or after January 1, 2020. In that case, Plans C and F generally aren’t available to you.
Conclusion
Medigap is one of the clearest ways to turn Medicare’s open-ended cost sharing into something that feels steadier and easier to plan for, especially when you’re protecting retirement income and want fewer financial surprises. And if you want help sorting out the timing, the plan letters, and the long-term tradeoffs, The Medicare Coach can guide you through Medicare Enrollment Concierge support so you can enroll with confidence, what would it feel like to choose your coverage knowing you truly understand what you’re buying?
