If you are approaching 65 or already enrolled in Medicare, you have probably noticed that Original Medicare (Part A and Part B) does not cover everything. Hospital stays, doctor visits, and outpatient services each come with copays, coinsurance, and deductibles that can add up quickly. A Medicare Supplement plan — also called Medigap — is designed to help fill those gaps.
But here is the challenge: there are multiple Medigap plans, each labeled with a letter, and they are not all the same. Understanding what each plan covers and how premiums vary can help you make a more informed decision about which option may work for your situation.
How Medicare Supplement Plans Work
Medicare Supplement plans are sold by private insurance companies and regulated by federal and state law. They work alongside Original Medicare — not instead of it. When you see a doctor or visit a hospital, Original Medicare pays its share of the approved amount first, and your Medigap plan may cover some or all of the remaining costs.
A few important points to know upfront:
- You must be enrolled in Medicare Part A and Part B to buy a Medigap plan.
- Plans are standardized by letter. A Plan G from one insurance company offers the same basic benefits as a Plan G from another company. What differs is the premium and the company’s customer service.
- You pay a monthly premium to the insurance company, on top of your Part B premium.
- Medigap plans do not include prescription drug coverage. If you want help with medication costs, you would need to enroll in a separate Part D drug plan.
The Standardized Medigap Plans
In most states, there are ten standardized Medigap plans: A, B, C, D, F, G, K, L, M, and N. (Plans C and F are not available to people who became eligible for Medicare on or after January 1, 2020.) Each plan covers a different set of Original Medicare cost-sharing gaps.
Here is what the most commonly purchased plans cover:
Plan A — The Foundation
Plan A is the most basic Medigap plan. It covers:
- Part A hospital coinsurance and hospital costs up to an additional 365 days after Medicare benefits are exhausted
- Part B coinsurance or copayment
- The first three pints of blood each year
- Part A hospice care coinsurance or copayment
Plan A does not cover the Part A deductible, the Part B deductible, or skilled nursing facility coinsurance. It is a straightforward option for people who want help with copays and coinsurance but are comfortable handling the deductibles themselves.
Plan B — Adds the Part A Deductible
Plan B includes everything in Plan A, plus:
- The Part A hospital deductible (the per-portion-period deductible)
It still does not cover the Part B deductible or skilled nursing facility coinsurance.
Plan C — Comprehensive (Pre-2020 Eligibility Only)
Plan C covers nearly everything Original Medicare does not:
- Part A deductible
- Part B deductible
- Part B coinsurance and copayments
- First three pints of blood
- Part A hospice coinsurance
- Skilled nursing facility coinsurance
- Part B excess charges
Plan C is not available to people who first became eligible for Medicare on or after January 1, 2020. If you were eligible before that date, you may still be able to buy Plan C.
Plan D — A Balanced Middle Ground
Plan D covers:
- Part A deductible
- Part B coinsurance and copayments
- First three pints of blood
- Part A hospice coinsurance
- Skilled nursing facility coinsurance
- Foreign travel emergency (up to plan limits)
Plan D does not cover the Part B deductible or Part B excess charges. It is a popular option for people who want solid coverage without paying for every possible gap.
Plan F — The Most Comprehensive (Pre-2020 Eligibility Only)
Like Plan C, Plan F is only available to people who were eligible for Medicare before January 1, 2020. Plan F covers everything Plan C covers, including Part B excess charges. For people who qualify, it provides the most complete Medigap coverage available.
Plan G — The Current Go-To for Full Coverage
Plan G is the most popular Medigap plan for people who became eligible for Medicare on or after January 1, 2020. It covers:
- Part A deductible
- Part B coinsurance and copayments
- First three pints of blood
- Part A hospice coinsurance
- Skilled nursing facility coinsurance
- Part B excess charges
- Foreign travel emergency (up to plan limits)
The one thing Plan G does not cover is the annual Part B deductible (which is $257 in 2026). Many people find this tradeoff worthwhile because Plan G premiums are often lower than Plan F premiums, and the Part B deductible is a predictable, once-a-year cost.
Plan K and Plan L — Cost-Sharing Plans
Plans K and L work differently from the others. Instead of covering all cost-sharing at once, they cover a percentage of many services — typically 50% for Plan K and 75% for Plan L. Once you reach a yearly out-of-pocket limit, the plan covers 100% of covered services for the rest of the year.
These plans tend to have lower monthly premiums, which can make them appealing if you are generally healthy and want protection against unexpected high-cost events.
Plan M — A Modest Option
Plan M covers:
- 50% of the Part A deductible
- Part B coinsurance and copayments
- First three pints of blood
- Part A hospice coinsurance
- Skilled nursing facility coinsurance
- Foreign travel emergency (up to plan limits)
Plan M may be worth considering if you want some deductible help without the higher premiums of Plan D or Plan G.
Plan N — Lower Premiums, Small Copays
Plan N is similar to Plan G but with a twist. In exchange for lower monthly premiums, you pay small copayments for some office visits and emergency room visits (up to $50 for office visits and up to $75 for ER visits, after the Part B deductible is met). Plan N does not cover Part B excess charges.
Plan N is a popular choice for people who do not visit the doctor frequently and want to keep their monthly costs down.
What About the Cost Difference Between Plans?
The benefits of each Medigap plan are standardized, but the premiums are not. Insurance companies set their own prices, and those prices can vary significantly. A Plan G from one company might cost $120 per month, while the same Plan G from another company costs $160 per month.
Several factors influence your premium:
- Where you live. Premiums vary by state and even by zip code.
- Your age. Some companies use “issue-age” pricing (based on your age when you buy the plan), while others use “attained-age” pricing (premiums increase as you get older).
- Tobacco use. Some companies charge higher premiums for tobacco users.
- The insurance company’s pricing method. Community-rated, issue-age, and attained-age pricing all produce different premium trajectories over time.
This is one reason it pays to compare. The plan that looks cheapest at age 65 may not be the most affordable over a 10- or 20-year span.
Medicare Supplement vs. Medicare Advantage: A Quick Note
Medigap and Medicare Advantage (Part C) are two different paths. A Medicare Advantage plan replaces your Original Medicare coverage and bundles it — often with drug coverage, dental, vision, and other perks — into a single plan from a private insurer. A Medigap plan works alongside Original Medicare and does not include those extras.
Neither option is universally “better.” The right choice depends on your health needs, your budget, your preferred doctors and hospitals, and how much flexibility you want. Some people value the broad provider network and predictable out-of-pocket structure of Medigap. Others prefer the all-in-one convenience and potentially lower premiums of Medicare Advantage.
What to Look for When Comparing Plans
When you sit down to compare Medicare Supplement plans, here are some questions worth asking:
- What does the plan cover? Look at the standardized benefit chart and make sure the plan covers the gaps that matter most to you.
- What does the plan cost? Get premium quotes from multiple insurance companies for the same plan letter.
- Does the company have a strong track record? Financial stability, customer service ratings, and complaint history all matter when you are counting on a plan to be there year after year.
- Are there any rate increase trends? Ask about the company’s history of premium increases. A low starting premium that climbs steeply may not be a bargain long-term.
- Do you need prescription drug coverage? Remember, Medigap plans do not include Part D drug coverage. You will need to enroll in a separate plan if you want help with medication costs.
- Does the plan include any extras? Some Medigap plans add benefits beyond the standard coverage, such as gym memberships or hearing aid discounts. These extras can vary by insurer.
How a Licensed Agent Can Help
Medicare Supplement plans are standardized, but the marketplace is not. Premiums, insurer reputation, rate history, and available extras all vary — and sorting through them on your own can feel overwhelming.
A licensed agent who specializes in Medicare can walk you through the options, compare plans side by side, and help you find a solution that aligns with your healthcare needs and your budget. They can also help you understand enrollment timing — for example, the six-month Medigap open enrollment period that starts when you turn 65 and are enrolled in Part B, which gives you the strongest guaranteed-issue rights.
Trek Insurance Solutions is a Third-Party Marketing Organization (TPMO). We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.
For more information, visit us at trekis.net or call 888-960-0442.