Original Medicare covers a lot, but it does not cover everything. The 20 percent coinsurance on Part B services, hospital deductibles, and unlimited out-of-pocket exposure can add up fast during a health crisis. That is exactly where Medigap plans step in. These standardized Medicare Supplement policies, purchased from private insurers, are designed to cover the financial gaps that Original Medicare leaves behind, and millions of Americans rely on them. This guide explains what each plan letter covers, which plans are closed to new enrollees, what they cost in 2026, and how to enroll at the best possible rate. Because Medicare figures are updated every year, verify the current numbers at Medicare.gov before you decide.
What Medigap Plans Cover
Medigap plans cover specific out-of-pocket costs that Original Medicare does not pay. The core benefits shared across most plans include Part A hospital coinsurance plus an additional 365 lifetime reserve days, Part B coinsurance or copayments, the first three pints of blood, and Part A hospice-care coinsurance. Beyond these basics, individual plan letters add benefits like the Part A deductible (about $1,736 in 2026), the Part B deductible (about $283 in 2026, and only certain plans still cover it), Part B excess charges, and foreign-travel emergency coverage. These deductible amounts change annually, so confirm the current figures at Medicare.gov.
Because Medigap plans are standardized by the federal government, a Plan G from one insurer is identical in benefits to a Plan G from another – the only variables between carriers are premium pricing, claims service, and financial-strength ratings. This standardization, established by the 1990 Omnibus Budget Reconciliation Act (with later refinements), makes comparison shopping straightforward once you decide on a plan letter. Medigap policies also have no provider networks: any doctor or hospital that accepts Medicare accepts your Medigap plan, anywhere in the country.
The Complete List of Medigap Plan Letters
Medicare currently recognizes ten Medigap plan types: A, B, C, D, F, G, K, L, M, and N. One rule matters before anything else: Plans C and F are closed to anyone who became eligible for Medicare on or after January 1, 2020. That change came from the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA), which barred new Medigap plans from covering the Part B deductible – the feature that defined C and F. If you were already Medicare-eligible before that date, you may still be able to buy or keep Plan C or Plan F; if you’re newly eligible, they are simply off the table, and Plan G is the closest equivalent. Here is how the letters break down.
Full-Coverage Plans
Plan F covers every gap in Original Medicare, making it the most comprehensive option – but again, only those who were eligible before January 1, 2020 can enroll in it. Plan G covers everything Plan F does except the Part B deductible, and it has become the top seller among new enrollees. There is also a high-deductible Plan G: it works like standard Plan G but you first pay a high annual deductible (verify the current amount at Medicare.gov) in exchange for a much lower monthly premium – a good fit for healthy enrollees who want catastrophic protection at a low ongoing cost. Plan C covers the same as Plan F minus Part B excess charges and is likewise closed to newly eligible beneficiaries. These plans offer maximum predictability, with annual out-of-pocket costs near zero once you pay your premium (and, for high-deductible G, once you meet the deductible).
Mid-Range and Cost-Sharing Plans
Plan N covers most gaps but introduces small copays: up to $20 for some office visits and up to $50 for emergency-room visits that do not result in an inpatient admission (Plan N also does not cover Part B excess charges). Plans K and L use a cost-sharing approach, covering 50 percent (K) or 75 percent (L) of certain benefits, with annual out-of-pocket limits that CMS updates each year – verify the current caps at Medicare.gov. Plan D covers everything Plan G covers except Part B excess charges. Plan M covers 50 percent of the Part A deductible and excludes the Part B deductible and excess charges. Plan G and Plan N are the two most popular choices for people enrolling today.
Basic Plans
Plan A and Plan B offer the most limited coverage. Plan A covers only the core benefits. Plan B adds Part A deductible coverage. Neither covers the Part B deductible, excess charges, or foreign-travel emergencies. These plans carry the lowest premiums but leave more financial risk on your shoulders.
How Much Medigap Plans Cost
Premiums vary significantly based on your age, location, gender, tobacco use, and the insurer’s pricing methodology. Drawing on Medicare.gov’s plan finder and published industry surveys, here are approximate monthly premium ranges for popular plans; treat them as ballpark figures and pull real quotes for your ZIP code:
Plan G: roughly $120 to $250. Plan F: roughly $150 to $300 (only for those still eligible). Plan N: roughly $80 to $180. Plan A: roughly $70 to $160. High-deductible Plan G often runs well under $60 in exchange for its deductible. These ranges reflect attained-age-rated policies for a 65-year-old and can be 20 to 40 percent higher in high-cost urban areas like New York, Miami, or Los Angeles compared with rural regions. Premiums also rise as you age on attained-age plans.
Insurers use three pricing models. Community-rated plans charge the same premium regardless of age, offering stability over time. Issue-age-rated plans base your premium on the age at which you buy, with increases tied to inflation and medical-cost trends. Attained-age-rated plans start low but increase as you get older, often becoming the most expensive option over a 20-year retirement horizon. Two carriers can price the identical plan letter very differently, so the model matters as much as today’s headline premium.
When and How to Enroll
Your Medigap Open Enrollment Period is the six-month window that starts the month you turn 65 and are enrolled in Medicare Part B. During this period, federal law guarantees your right to buy any Medigap plan sold in your state at the standard rate, with no medical underwriting and no health-related premium surcharges. This is the single most important enrollment window in the Medigap world – and it does not automatically repeat.
If you miss this window, you can still apply for Medigap plans, but insurers in most states may use medical underwriting to evaluate your application. Pre-existing conditions like diabetes, heart disease, or COPD could lead to higher premiums or outright denial. A handful of states (for example New York, Connecticut, Massachusetts, and Maine) offer stronger continuous or annual guaranteed-issue protections; rules differ by state and change over time. Consult your healthcare policy guide and your state’s department of insurance for specifics.
Medigap Doesn’t Cover Prescription Drugs
This trips up a lot of new enrollees: standardized Medigap plans do not include prescription drug coverage. Older, pre-2006 Medigap policies sometimes bundled drug benefits, but current plans do not. To cover medications, you need a separate Medicare Part D prescription drug plan (or a Medicare Advantage plan that includes drug coverage instead of Medigap). If drug costs are a concern, look into Medicare Extra Help, the low-income subsidy that reduces Part D premiums and copays. Enrolling in Part D during your Initial Enrollment Period also helps you avoid the Part D late-enrollment penalty.
Medigap Plans vs. Medicare Advantage
The choice between Medigap and Medicare Advantage is one of the biggest decisions you will make when entering Medicare. Medigap vs Medicare Advantage is a detailed comparison, but the core trade-off is simple: Medigap offers higher premiums with lower out-of-pocket costs and unrestricted provider access, while Medicare Advantage offers lower premiums with higher potential out-of-pocket costs and network restrictions.
If you prioritize seeing any doctor in the country without referrals, traveling freely, and having predictable healthcare expenses, Medigap is typically the better fit. If your budget cannot accommodate a monthly Medigap premium and you are comfortable with network-based care and annual out-of-pocket maximums, a well-rated Medicare Advantage plan in your area may be a reasonable alternative. Remember you generally cannot hold both at once.
Common Mistakes to Avoid
Waiting too long to enroll is the most costly mistake. Every month past your Open Enrollment Period increases the risk that a health issue could complicate underwriting. Choosing the cheapest plan without considering long-term premium growth is another pitfall – an attained-age-rated plan from a lesser-known carrier might save you $30 a month at 65 but cost significantly more than a community-rated policy by the time you reach 75.
Failing to compare at least three to five carriers is also common. Since benefits are identical within the same plan letter, premium differences of 15 to 30 percent between insurers represent pure savings for the same coverage. Finally, do not assume your Medigap plan covers prescription drugs. It does not – you need a separate Part D plan.
Frequently Asked Questions
Are Plans F and C really closed?
Yes, for new beneficiaries. Plans C and F are closed to anyone who first became eligible for Medicare on or after January 1, 2020, under MACRA, because they cover the Part B deductible. People who were eligible before that date may still enroll in or keep these plans where available. If you’re newly eligible and want comprehensive coverage, Plan G is the closest alternative.
Do Medigap plans cover dental, vision, or hearing?
No. Standardized Medigap plans do not include dental, vision, or hearing benefits. You would need to purchase separate coverage or pay out of pocket. Some insurers bundle discount programs alongside Medigap policies, but those are not part of the standardized benefit package.
Can I have a Medigap plan and Medicare Advantage at the same time?
No. It is generally illegal for an insurer to sell you a Medigap policy while you are enrolled in a Medicare Advantage plan. You must return to Original Medicare before a Medigap plan can take effect.
Will my Medigap premium increase every year?
Most premiums increase over time due to medical inflation and, for attained-age-rated plans, your advancing age. Increases commonly land in the low-to-mid single-digit percentages annually, though some years run higher. Community-rated plans tend to have the most predictable increases.
Are Medigap plans available to people under 65?
Federal law does not require insurers to sell Medigap to people under 65 who qualify for Medicare due to disability or end-stage renal disease. However, many states have passed laws mandating Medigap access for disabled beneficiaries under 65, often at higher premiums. Check your state’s requirements through the NAIC or your state insurance department.
Making Your Medigap Decision
Medigap plans remain one of the most effective tools for protecting your retirement savings from unpredictable healthcare costs. The standardized benefit structure makes comparison shopping simple, and the guaranteed-issue protections during Open Enrollment ensure you can secure coverage at the best possible rate. Start by deciding which plan letter fits your budget and risk tolerance (Plan G and Plan N are the usual starting points for new enrollees), remember that Plans F and C are closed if you became eligible in 2020 or later, pair your choice with a Part D drug plan, compare premiums from multiple carriers, and enroll as early as you can. For more on how healthcare costs affect your retirement planning, explore our complete guide.
TL;DR & disclaimer: Medigap (Medicare Supplement) plans are standardized into letters A-N, so a given letter is identical across insurers – only price and service differ. Plans C and F are closed to anyone first eligible for Medicare on or after January 1, 2020; Plan G (including a high-deductible version) and Plan N are the popular choices today. Medigap has no networks but does not cover prescription drugs, so you’ll need a separate Part D plan. Enroll during your 6-month Medigap Open Enrollment Period to avoid medical underwriting. The 2026 figures here (Part A deductible about $1,736; Part B deductible about $283) and premium ranges can change – verify current numbers at Medicare.gov. This is general educational information, not insurance advice.
Sources
- Medicare.gov – “How to compare Medigap policies” and “Medicare costs” (medicare.gov)
- CMS – 2026 Medicare Parts A & B premiums and deductibles (cms.gov / medicare.gov)
- CMS / MACRA – Medicare Access and CHIP Reauthorization Act of 2015 (closure of Part B deductible coverage in new Plans C and F)
- National Association of Insurance Commissioners (NAIC) – Medigap standardization and state protections (naic.org)