More than 14 million Americans rely on Medigap policies to fill the coverage gaps left by Original Medicare, and that number continues to climb each year. Understanding Medicare Supplement plans 2025 is essential whether you are turning 65 this year, aging into Medicare from a disability, or re-evaluating a policy you already hold. This guide breaks down the plan options, average costs, enrollment rules, and key changes that affect beneficiaries in 2025.
What Are Medicare Supplement Plans?
Medicare Supplement plans, also called Medigap, are private insurance policies designed to cover some or all of the out-of-pocket costs that Original Medicare (Parts A and B) does not pay. These costs include the Part A deductible ($1,632 in 2025), the Part B deductible ($257 in 2025), Part B coinsurance of 20 percent, skilled nursing facility coinsurance, and excess charges from providers who do not accept Medicare assignment.
Medigap plans are standardized by the federal government. Each plan is identified by a letter, and every insurer selling a given plan letter must offer identical benefits. The plans available in most states are A, B, C, D, F, G, K, L, M, and N. Massachusetts, Minnesota, and Wisconsin use their own standardized plan structures.
Key Changes for Medicare Supplement Plans 2025
The most significant ongoing change is the continued unavailability of Plans C and F to new Medicare beneficiaries. Under the Medicare Access and CHIP Reauthorization Act (MACRA), anyone who became eligible for Medicare on or after January 1, 2020, cannot purchase Plan C or Plan F. This has shifted enrollment toward Plan G and Plan N as the most comprehensive options for newer beneficiaries.
For 2025, the Part B deductible rose to $257, up from $240 in 2024. This increase directly affects Plan G policyholders, who must pay the Part B deductible before their Medigap coverage kicks in. The Part A deductible increased to $1,632 per benefit period. Plans that cover the Part A deductible, including Plans A through G, absorb this cost on behalf of the enrollee.
CMS data shows average Medigap premium increases of 3 to 6 percent nationally in 2025, though some insurers held rates steady or even reduced premiums in competitive markets. Premium trends for medicare supplement plans 2025 vary substantially by state, carrier, and plan letter.
Comparing the Most Popular Plan Letters
Plan G has become the most popular Medigap plan for new enrollees. It covers everything that Plan F covers except the Part B deductible. Monthly premiums for Plan G in 2025 typically range from $120 to $280 depending on age, location, gender, and tobacco status. Because enrollees pay the $257 Part B deductible themselves, Plan G premiums tend to be $30 to $60 per month lower than Plan F, making it more cost-effective for most beneficiaries.
Plan N is the second most popular choice. It covers the same benefits as Plan G except it does not cover Part B excess charges and requires a copay of up to $20 for office visits and up to $50 for emergency room visits that do not result in admission. Plan N premiums typically range from $90 to $210 per month, offering meaningful savings for beneficiaries who see providers that accept Medicare assignment. For a detailed side-by-side analysis, see our Medicare Plan N vs Plan G comparison.
Plans K and L are high-deductible alternatives that cover 50 percent and 75 percent of benefits respectively, with annual out-of-pocket limits of $7,060 and $3,530 in 2025. These plans carry lower premiums but expose you to higher costs if you need significant care.
Average Costs for Medicare Supplement Plans 2025
Premium costs for medicare supplement plans 2025 depend on several factors. The table below shows approximate monthly premium ranges for a 65-year-old nonsmoker enrolling during their Medigap Open Enrollment Period.
Plan A: $90 to $200 per month. Plan B: $100 to $230 per month. Plan C (pre-2020 eligible only): $150 to $300 per month. Plan D: $110 to $240 per month. Plan F (pre-2020 eligible only): $160 to $330 per month. Plan G: $120 to $280 per month. Plan N: $90 to $210 per month. Plan K: $50 to $120 per month. Plan L: $70 to $170 per month.
These ranges are based on rate filings reported to state insurance departments and data compiled by the Kaiser Family Foundation (KFF). Your actual premium will depend on your ZIP code, the insurer’s rating method (attained-age, issue-age, or community-rated), and any applicable discounts. Use our Medigap Cost Comparison Chart for a more detailed breakdown.
How to Enroll in a Medigap Plan
The best time to enroll is during your six-month Medigap Open Enrollment Period, which begins on the first day of the month you turn 65 and are enrolled in Medicare Part B. During this window, insurers must sell you any Medigap policy they offer at the standard rate, regardless of your health status. They cannot deny coverage or add exclusion periods for pre-existing conditions.
If you miss this window, you can still apply for a Medigap policy, but the insurer can use medical underwriting. That means they can charge you more or decline your application based on your health history. Certain life events, such as losing employer coverage or leaving a Medicare Advantage plan within 12 months of joining, trigger guaranteed-issue rights that let you enroll without underwriting.
For complete enrollment timeline details, check our Medicare Enrollment 2025 Guide and our page on Medicare AEP.
State-Specific Considerations
While Medigap benefits are federally standardized, premiums and consumer protections vary by state. California, for example, offers an annual open enrollment period every year during your birthday month, giving beneficiaries guaranteed-issue rights to switch plans. Missouri, Oregon, and Connecticut provide similar birthday-rule protections. New York requires community rating, meaning premiums cannot increase based on age, though starting rates tend to be higher.
If you live in a state with strong consumer protections, you have more flexibility to start with a lower-cost plan and switch later. Beneficiaries in states without birthday rules should be more deliberate about their initial plan choice because switching may require medical underwriting. For state-specific guidance, see our articles on Medicare Supplement Plans in PA, Medicare Supplement Plans Maryland, and Medicare Supplement Plans California.
Medigap vs Medicare Advantage
Before choosing a Medigap policy, it is worth understanding how it compares to Medicare Advantage (Part C). Medicare Advantage plans often have lower monthly premiums and may include dental, vision, and prescription drug coverage. However, they use provider networks and require referrals in many cases. Medigap plans give you the freedom to see any provider nationwide that accepts Medicare and offer more predictable out-of-pocket costs.
According to KFF, about 31 percent of Medicare beneficiaries were enrolled in Medigap plans in 2023, while Medicare Advantage enrollment has grown to cover more than half of all beneficiaries. The right choice depends on your healthcare needs, travel habits, provider preferences, and budget. Our detailed comparison at Medigap vs Medicare Advantage can help you decide.
Frequently Asked Questions
Can I add prescription drug coverage to my Medigap plan?
No. Medigap plans do not include prescription drug coverage. You need to enroll in a standalone Medicare Part D plan separately. You can find information about prescription drug costs and coverage gaps in our guide to the Medicare Part D donut hole.
Is Plan G the best value for 2025?
For most new beneficiaries, Plan G offers the strongest combination of comprehensive coverage and reasonable premiums. You pay only the annual Part B deductible of $257 out of pocket, and everything else is covered. Over time, Plan G enrollees typically spend less than Plan F enrollees because the premium difference exceeds the deductible amount. Learn more in our guide to the best Medicare Supplement plan.
What happens if my Medigap insurer raises premiums significantly?
You have the right to switch insurers at any time by applying for a new policy. However, unless your state offers guaranteed-issue rights outside of your initial enrollment period, the new company can underwrite your application. Shopping around every two to three years and comparing rates is a good practice.
Do Medicare Supplement plans 2025 cover telehealth?
Medigap plans cover the same services that Original Medicare covers, including telehealth visits that Medicare has approved. Your plan pays the Part B coinsurance for covered telehealth services just as it would for an in-person visit. Some insurers also offer supplemental telehealth benefits at no extra cost.
Choosing the Right Plan for Your Situation
Start by estimating your expected healthcare usage for the year. If you anticipate frequent doctor visits, specialist consultations, or potential hospitalizations, a comprehensive plan like Plan G provides peace of mind with minimal out-of-pocket exposure. If you are generally healthy and want to keep premiums low, Plan N or Plan K may suit your needs. Compare quotes from at least three carriers using the Medicare.gov plan finder or an independent broker. Factor in not just the monthly premium but also the insurer’s rate increase history, financial strength rating, and customer satisfaction scores. For further reading on plan comparisons and Medicare policy topics, visit our healthcare policy guide and our healthcare costs guide.