What Is a Medicare Supplement?

When it comes to Medicare, things can get confusing really quickly. And while “Medicare Supplement” is a widely used term, we know that not everyone is on the same page.

In this article, we’ll explain everything you wanted to know (and perhaps didn’t want to know) about Medicare Supplement plans.

Watch: Understanding Medicare Supplements

In this video, Shelbie from Senior Allies explains how Medicare Supplements work and why Plan G is often the best choice for comprehensive coverage.

The Many Names of Medicare Supplements

For starters, Medicare Supplements go by many names:

• Medicare Supplement
• Medigap
• Med Supp
• Med Sup
• Supplemental Insurance

A Medicare Supplement is an insurance policy that pays for some of the remaining health care costs that Medicare alone doesn’t cover, such as copayments, coinsurance, and deductibles.

Other perks of a Medicare Supplement policy include medical care when you’re travelling internationally, coverage for excess medical charges, and blood.

It’s important to know that a Medicare Supplement only approves charges that Medicare approves. If an item or service isn’t already approved by Medicare – such as dental care, vision exams, or nursing home stays – a Medicare Supplement won’t approve it either.

When Can You Get a Medicare Supplement?

If you’re eligible for Medicare, you’re eligible for a Medicare Supplement. You become eligible for Medicare at age 65, and possibly sooner if you have a disability.

The month you turn 65, you’re eligible for the open enrollment period. This lasts for the next 6 months. For example, if you turn 65 in January and enroll in Medicare Part B, you can purchase a Medigap policy from January to June.

Even if you’re 65, though, you can choose to put off signing up for Medicare. For example, if you’re on a group plan provided by your employer, and you don’t plan on retiring just yet.

A few things to know about applying for a Medicare Supplement:

• In order to have a Medicare Supplement, you must have Medicare Parts A and B.
• You cannot have a Medicare Supplement if you’re on a Medicare Advantage Plan.
• It’s illegal for anyone to sell you a Medicare Supplement if you have a Medicare Medical Savings Account (MSA) Plan.

How Is a Medicare Supplement Different From Other Insurances?

A Medicare Supplement is designed to work with Medicare. You can think of it as a partnership.

For example, if you have a $1,000 bill from a doctor visit, Medicare will pay 80% of the approved charges and a Medicare Supplement insurance will pay all or part of the remaining 20% (depending on which supplement you choose).

In other words, Medicare gets the bill first, and they pay their portion. Then, they send the rest of the bill to your Medicare Supplement, and it picks up the remaining amount.

A Medicare Supplement is NOT:

• A Medicare Advantage Plan
• A Medicare Prescription Drug Plan
• Medicaid
• TRICARE or CHAMPVA
• Long-term care insurance
• Indian Health Service, Tribal, and Union Indian Health plans
• Employer or union plans

A Medicare Supplement works with Medicare only. If you don’t have Medicare, you can’t have a Medicare Supplement.

Are There Different Types of Medicare Supplements?

A Medicare Supplement is a blanket term for an insurance plan that picks up the leftover costs of Medicare.

However, there are different types of Medicare Supplements.

These plans are organized by using a lettering system – A, B, C, D, F, G, K, L, M, and N.

Each letter represents a different set of benefits. Some supplements offer more coverage than others, and those plans are generally more expensive to purchase.

Note: Plans C and F are no longer available to new Medicare beneficiaries who became eligible for Medicare on or after January 1, 2020. If you already have one of these plans, you can keep it, but new enrollees cannot purchase them.

Currently, the most popular plans are G and N, because they offer excellent coverage at competitive rates.

Plan G is known as the best overall value, offering comprehensive coverage with just one gap – you pay the Medicare Part B deductible (which is $257 in 2025). After that, Plan G covers virtually all Medicare-approved expenses.

Plan N offers great coverage with a few cost-sharing features:

• Like Plan G, it doesn’t pick up the Medicare Part B deductible
• It doesn’t pick up Medicare Part B excess charges
• It covers 80% of medical costs while you’re travelling internationally
• You pay up to a $20 copayment for office visits and up to $50 for emergency room visits

Plan N is typically the most budget-friendly option, making a it a good choice for those wanting to balance coverage with affordability.

How Much Do Medicare Supplements Cost?

Like most insurances, the cost of Medicare Supplements vary based on several factors:

• Your age (younger = typically cheaper, depending on pricing method)
• Your zip code (prices vary significantly by location)
• Whether you're a tobacco user or not (non-tobacco = cheaper)
• Gender (in states where allowed, females often pay less)
• Insurance company pricing method (community-rated, issue-age, or attained-age)

Not sure what a Medicare Supplement would cost you? Let us do some rate shopping on your behalf.

Key 2025 Medicare Supplement Updates

Medicare Part B Deductible: The Medicare Part B deductible for 2025 is $240, which affects Plans G and N since neither covers this deductible.

High-Deductible Plan G: This option requires you to pay a $2,870 deductible (2025 amount) before the plan begins paying benefits, but it offers significantly lower monthly premiums.

Guaranteed Issue Rights: You still have guaranteed issue rights during your 6-month Medigap Open Enrollment Period when you first enroll in Medicare Part B at age 65 or older.

Need Help Choosing the Right Medicare Supplement?

Our team of dedicated, licensed agents can help you as little or as much as you need. Whether it's answering a few questions about Medicare or creating a comprehensive Medicare plan with you, we are your Senior Allies.

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