Medicare Supplement plans — also called Medigap — are extra insurance policies sold by private companies that help pay the out-of-pocket costs Original Medicare leaves behind. These costs include deductibles, coinsurance, and copayments that can add up fast without added protection.
Under the Social Security Act, insurance companies must sell standardized Medigap plans labeled by letter (A through N). Federal law requires that every plan with the same letter offers the same benefits no matter which company sells it. The only difference between two Plan G policies from two different companies is the price.
About 13.5 million beneficiaries were enrolled in Medigap policies across the U.S. as of December 2024. That figure represents roughly 42% of all people enrolled in traditional Medicare.
Here’s what you’ll learn in this article:
- 🔍 What each of the 10 Medigap plans covers and how they fill the gaps in Original Medicare
- 💰 Real-world cost examples, average premiums, and how pricing works across different companies
- ⚠️ Costly enrollment mistakes that could lock you out of coverage or raise your premiums for life
- 🏥 Three detailed scenarios showing how Medigap pays your bills when you get care
- ⚖️ How Medigap stacks up against Medicare Advantage — and which choice protects your wallet better
What Original Medicare Doesn’t Pay For (And Why Medigap Exists)
Original Medicare — Part A (hospital insurance) and Part B (medical insurance) — covers a large share of health care costs but not all of them. Part A carries an inpatient hospital deductible of $1,736 in 2026, plus daily coinsurance of $434 per day for hospital days 61 through 90. Part B requires a $283 annual deductible in 2026, and after that, you still owe 20% coinsurance on most outpatient services.
These gaps can create serious financial exposure. A single hospital stay lasting 70 days could cost you $1,736 for the deductible plus $4,340 in coinsurance (10 days × $434). Skilled nursing facility care adds $217 per day in coinsurance for days 21 through 100.
Medigap policies exist to absorb these costs. When you receive care, Medicare pays its share first, and then your Medigap plan picks up some or all of the remaining balance. You pay a monthly premium to the private insurance company on top of your Part B premium of $202.90 in 2026.
The 10 Standardized Medigap Plans — What Each One Covers
Every state except Massachusetts, Minnesota, and Wisconsin uses the same standardized plan letters. Each letter represents a specific package of benefits. All insurance companies must offer at least Plan A, and they choose which other plans to sell in your state.
How the Benefits Break Down Across Plans
| Benefit | Plans That Cover 100% |
|---|---|
| Part A coinsurance + 365 extra hospital days | A, B, C, D, F, G, K, L, M, N |
| Part B coinsurance/copayment | A, B, C, D, F, G, M (Plan K = 50%, Plan L = 75%, Plan N = 100% with copays) |
| Blood (first 3 pints) | A, B, C, D, F, G, M, N (Plan K = 50%, Plan L = 75%) |
| Part A hospice coinsurance | A, B, C, D, F, G, M, N (Plan K = 50%, Plan L = 75%) |
| Skilled nursing facility coinsurance | C, D, F, G, N (Plan K = 50%, Plan L = 75%, Plan M = 100%) |
| Part A deductible ($1,736 in 2026) | B, C, D, F, G, N (Plan K = 50%, Plan L = 75%, Plan M = 50%) |
| Part B deductible ($283 in 2026) | C, F only |
| Part B excess charges | F, G only |
| Foreign travel emergency (80%) | C, D, F, G, M, N |
Plan G — The Most Popular Choice for New Enrollees
Plan G covers everything except the annual Part B deductible of $283. That means after you pay $283 once per year, you owe nothing else for Medicare-approved services. Plan G is the most popular Medigap plan for beneficiaries who became eligible for Medicare after January 1, 2020.
Monthly premiums for a 65-year-old nonsmoker range from about $118 to $279 depending on location and carrier. In Dallas, Texas, for example, Cigna charges around $167 per month while Aetna charges about $220 for the same Plan G coverage.
Plan G also covers Part B excess charges — the extra amount a doctor can charge above what Medicare approves. Only Plans F and G offer this protection. Without it, a non-participating doctor can charge you up to 15% above Medicare’s approved amount.
Plan F — The Most Comprehensive (But Limited Availability)
Plan F is the only Medigap plan that covers every single gap in Original Medicare, including the Part B deductible. It effectively gives you $0 out-of-pocket costs beyond your monthly premium. The catch: Plan F is only available to people who became eligible for Medicare before January 1, 2020.
The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) prohibited new Medigap policies from covering the Part B deductible for anyone becoming Medicare-eligible on or after January 1, 2020. This law eliminated Plans C and F for new enrollees.
Premium ranges for Plan F run from roughly $143 to $514 per month, depending on your age, location, and insurance company. Because the Plan F risk pool is aging — no new enrollees can join — premiums tend to rise faster than Plan G premiums over time.
Plan N — The Budget-Friendly Alternative
Plan N offers coverage similar to Plan G but at lower monthly premiums. The trade-off is small copayments: up to $20 for some office visits and up to $50 for emergency room visits that don’t result in a hospital admission. Plan N does not cover Part B excess charges.
Sample monthly premiums for Plan N range from about $85 to $212 for a 65-year-old nonsmoker. In Texas, Cigna offers Plan N for around $121 per month, while Aetna charges approximately $151.
Plan N works well for people who are healthy, don’t see specialists often, and want to save on monthly costs. The annual savings compared to Plan G can be $300 to $600 per year — but you take on more risk if you need frequent care.
Plans K and L — The Cost-Sharing Plans
Plans K and L are unique because they only cover a percentage of your costs instead of 100%. Plan K covers 50% of most benefits, while Plan L covers 75%. Both plans include an annual out-of-pocket limit that caps your spending each year.
In 2026, Plan K’s out-of-pocket limit is $8,000 and Plan L’s is $4,000. Once you hit that cap, the plan pays 100% of covered services for the rest of the calendar year. These plans offer the lowest monthly premiums — sometimes as low as $50 to $80 per month.
Plans A, B, D, and M — Less Common but Still Available
Plan A is the most basic Medigap plan. It covers Part B coinsurance, the first 3 pints of blood, Part A hospice coinsurance, and the 365 extra hospital days. It does not cover the Part A deductible, skilled nursing facility coinsurance, or foreign travel emergencies.
Plan B adds Part A deductible coverage to Plan A’s benefits. Plan D adds skilled nursing facility coinsurance and foreign travel emergency coverage on top of Plan B. Plan M covers 50% of the Part A deductible and includes foreign travel emergency at 80%.
High-Deductible Plan Options
Plans F and G offer a high-deductible version in some states. You must pay $2,950 in 2026 for Medicare-covered costs before the plan starts paying. Monthly premiums for high-deductible Plan G range from roughly $42 to $93.
High-deductible plans suit people who want catastrophic protection without high monthly premiums. If you rarely see the doctor and don’t take expensive medications, this option can save you over $1,000 per year in premiums compared to standard Plan G.
How Medigap Actually Pays Your Bills — 3 Real-World Scenarios
Scenario 1: Maria, Age 67 — A 5-Day Hospital Stay With Plan G
Maria has Original Medicare and Medigap Plan G. She pays $180 per month for her Medigap premium and has already met her $283 Part B deductible for the year. She is admitted to the hospital for pneumonia and stays for 5 days.
| What Happens | What Maria Pays |
|---|---|
| Part A hospital deductible ($1,736) | $0 — Plan G covers it |
| Hospital room, nursing, meals (5 days) | $0 — Medicare Part A covers days 1–60, Plan G covers any remaining coinsurance |
| Doctor visits during hospital stay (Part B) | $0 — Plan G covers the 20% coinsurance |
| Lab work and X-rays | $0 — Plan G covers coinsurance after Medicare pays 80% |
| Maria’s total out-of-pocket for this stay | $0 |
Without Plan G, Maria would owe $1,736 just for the Part A deductible — plus 20% of all doctor and lab charges. Her Medigap policy absorbed every dollar of those costs.
Scenario 2: Robert, Age 70 — Frequent Specialist Visits With Plan N
Robert has Plan N and sees a cardiologist every month, plus visits his primary care doctor quarterly. He has not yet met his Part B deductible at the start of the year.
| What Happens | What Robert Pays |
|---|---|
| Part B annual deductible | $283 (Plan N does not cover this) |
| 12 cardiologist visits (Part B coinsurance) | Up to $240 total ($20 copay × 12 visits) |
| 4 primary care visits (Part B coinsurance) | Up to $80 total ($20 copay × 4 visits) |
| One ER visit (not admitted) | $50 copay |
| Part A deductible if hospitalized | $0 — Plan N covers it |
| Robert’s estimated annual out-of-pocket | Approximately $653 |
Robert’s Plan N premium saves him about $40 per month compared to Plan G in his area. That’s $480 per year in premium savings. Even with the copays and deductible, his total costs remain predictable and manageable.
Scenario 3: Linda, Age 66 — Cancer Treatment With Plan F
Linda was eligible for Medicare before 2020 and holds Plan F. She is diagnosed with breast cancer and needs surgery, chemotherapy, and months of follow-up care.
| What Happens | What Linda Pays |
|---|---|
| Part A hospital deductible for surgery | $0 — Plan F covers it |
| Part B deductible | $0 — Plan F covers it |
| 20% coinsurance on chemotherapy | $0 — Plan F covers all coinsurance |
| Surgeon and oncologist fees | $0 — Plan F covers Part B coinsurance |
| Skilled nursing facility coinsurance (if needed) | $0 — Plan F covers it |
| Linda’s total out-of-pocket for cancer treatment | $0 beyond her monthly premium |
Without Medigap, Linda’s 20% share of chemotherapy alone could reach $10,000 or more depending on the drug regimen. Plan F covers all Medicare gaps, making her total financial exposure zero beyond the monthly premium.
The Enrollment Window That Can Make or Break Your Coverage
Your One-Time 6-Month Open Enrollment Period
Federal law gives you a single 6-month Medigap Open Enrollment Period. It begins the first day of the month you turn 65 and are enrolled in Medicare Part B. This is a one-time window — it does not repeat every year.
During this window, no insurance company can deny you a Medigap policy, charge you more because of health problems, or use medical underwriting against you. You can buy any Medigap plan sold in your state, from any licensed carrier.
After this 6-month period closes, everything changes. Insurance companies can require medical underwriting to evaluate your health history. They can deny your application, charge higher premiums, or impose a pre-existing condition waiting period of up to 6 months.
What Happens If You Miss the Window
Missing your Medigap Open Enrollment Period creates real consequences. You may face fewer plan choices, higher premiums, or flat-out denial of coverage. If you developed diabetes, had a heart attack, or were diagnosed with cancer after turning 65, an insurer outside of your open enrollment can legally refuse to sell you a policy.
The pre-existing condition look-back period covers any condition treated or diagnosed within 6 months before your Medigap policy starts. If you have 6 months of continuous creditable coverage (prior health insurance), the insurer cannot impose this waiting period.
Guaranteed Issue Rights — Your Safety Net Outside Open Enrollment
Federal law provides specific situations where you can buy a Medigap policy outside your Open Enrollment Period without medical underwriting. These are called guaranteed issue rights.
You have guaranteed issue rights when:
- Your Medicare Advantage plan leaves Medicare or stops serving your area
- Your employer or union group health plan that supplements Medicare ends
- Your Medigap insurance company goes bankrupt
- You joined a Medicare Advantage plan when first eligible and want to switch back within 12 months (trial right)
- You dropped a Medigap policy to try Medicare Advantage for the first time and want to return within 12 months (trial right)
In each situation, you must apply within 63 days after your prior coverage ends. The insurer must sell you Plan A, B, C, D, F, or G (C and F only if you were Medicare-eligible before 2020) without any health screening.
How Insurance Companies Price Your Medigap Premium
Three pricing methods exist, and the one your insurance company uses directly affects how much you pay now and in the future. Understanding these methods can save you thousands of dollars over the life of your policy.
| Pricing Method | How It Works |
|---|---|
| Community-rated (no-age-rated) | Everyone pays the same premium regardless of age; premiums rise only with inflation, not your birthday |
| Issue-age-rated (entry-age-rated) | Premium is based on the age you were when you bought the policy; it stays locked to that age tier and rises only with inflation |
| Attained-age-rated | Premium is based on your current age and increases every year as you get older; starts cheapest but becomes most expensive over time |
An attained-age-rated policy might cost $120 per month at age 65 but climb to $132 by age 67 — and keep rising every year. A community-rated policy might start at $165 but hold steadier over time. Issue-age-rated policies tend to offer the best long-term value because your rate stays tied to the age you enrolled.
All three methods can also experience premium increases due to inflation, rising health care costs, and changes in the insurer’s claims experience. The key difference is whether your age itself pushes the price up annually.
States With Their Own Medigap Rules: Massachusetts, Minnesota, and Wisconsin
These three states do not use the standard lettered plan system. They created their own non-standardized Medigap structures before the federal government standardized plans in 1992 and were allowed to keep their unique systems.
Massachusetts
Massachusetts offers only three plans: Core Plan, Supplement 1, and Supplement 1A. The Core Plan covers Part A and Part B coinsurance, blood, and hospice care. Supplement 1 adds the Part A deductible, skilled nursing coinsurance, foreign travel emergency, and the Part B deductible — making it similar to the old Plan F. Supplement 1A is like Supplement 1 but without the Part B deductible.
Minnesota
Minnesota uses a Basic Plan plus optional riders. Beneficiaries start with a basic package and then add specific riders to customize their coverage — such as the Part A deductible rider, the Part B deductible rider, or the foreign travel emergency rider. Minnesota also offers an Extended Basic Plan that bundles several common riders together.
Wisconsin
Wisconsin follows a similar approach with a Basic Plan and add-on riders. You pick the Basic Plan and then select individual riders for benefits like the Part A deductible, skilled nursing facility coinsurance, Part B deductible, and Part B excess charges. This gives Wisconsin residents the most flexibility to build a Medigap policy tailored to their needs.
Medigap vs. Medicare Advantage — The Real Differences
Many people confuse Medigap with Medicare Advantage (Part C), but they work in fundamentally different ways. A Medigap policy supplements Original Medicare, while Medicare Advantage replaces Original Medicare entirely. You cannot hold both at the same time.
| Feature | Medigap (Medicare Supplement) | Medicare Advantage (Part C) |
|---|---|---|
| Monthly premium | $90 – $300+ (depends on plan and carrier) | Often $0 – $100 |
| Doctor/hospital choice | Any Medicare-accepting provider nationwide | Usually limited to a network |
| Referrals needed | No | Often yes |
| Out-of-pocket maximum | Plans K/L have a cap; most others = near $0 after premium | Up to $9,250 per year in 2026 |
| Prescription drug coverage | No — must buy separate Part D plan | Usually included |
| Prior authorization | Not required | Frequently required |
| Travel coverage | Plans C, D, F, G, M, N cover 80% of foreign travel emergency | Usually no foreign coverage |
A real-world cost comparison shows the difference clearly. Someone with Medigap Plan G diagnosed with cancer might pay only $283 total (the Part B deductible) for an entire year of treatment. The same person on Medicare Advantage could pay $40–$60 per specialist visit, $90–$150 per ER visit, plus reach a $9,250 out-of-pocket maximum.
Pros and Cons of Medicare Supplement Plans
| ✅ Pros | ❌ Cons |
|---|---|
| Predictable costs — most plans leave you with little to no out-of-pocket expenses beyond the premium | Higher monthly premiums — Medigap costs $90–$300+ per month vs. $0 for many Medicare Advantage plans |
| Freedom to see any doctor who accepts Medicare, anywhere in the U.S. | No prescription drug coverage — you must buy a separate Part D plan, adding another monthly premium |
| No referrals or prior authorization needed for specialists or procedures | No extra benefits — Medigap does not cover dental, vision, hearing, or fitness programs |
| Guaranteed renewable — your insurer cannot cancel your policy as long as you pay the premium | Medical underwriting outside Open Enrollment — you may be denied coverage if you apply late |
| Travel protection — many plans cover 80% of foreign emergency care | Premiums increase over time — especially with attained-age-rated policies, costs can rise significantly as you age |
| Standardized benefits — you can compare apples to apples across insurance companies | No out-of-pocket cap on most plans — only Plans K and L have an annual spending limit (though most plans cover nearly everything) |
Mistakes to Avoid When Buying Medigap
Missing your 6-month Open Enrollment Period is the most damaging mistake. Once it closes, you lose your guaranteed right to buy any Medigap plan regardless of health. You cannot get this window back.
Choosing the cheapest premium without understanding the pricing method can backfire. An attained-age-rated plan looks affordable at 65 but can double by age 80. Ask every insurer whether they use community, issue-age, or attained-age rating before you sign up.
Assuming Plan F is always better than Plan G costs people money. Plan F premiums are often $100+ per month more than Plan G, but the only extra benefit is coverage of the $283 Part B deductible. Over a year, Plan G can save you $1,107 or more compared to Plan F.
Buying Medigap without shopping multiple companies leaves money on the table. Because benefits are identical across companies for the same lettered plan, the only variable is price. Premium differences of $50–$100 per month for the same plan are common.
Not understanding what Medigap doesn’t cover leads to surprises. Medigap plans do not cover long-term nursing home care, dental care, vision services, hearing aids, glasses, or private-duty nursing. You need separate coverage for those needs.
Dropping a Medigap policy to try Medicare Advantage without knowing your return rights is risky. Federal law gives you a trial right to return to Medigap within 12 months if you joined Medicare Advantage when first eligible for Medicare. Outside of that window, you may not be able to get Medigap again if your health has changed.
Do’s and Don’ts of Medigap Enrollment
Do enroll during your 6-month Open Enrollment Period — this is the one time you have guaranteed acceptance into any plan without health questions.
Do compare the same lettered plan across at least 3 to 5 insurance companies to find the lowest premium for identical coverage.
Do ask about household, non-smoker, and automatic payment discounts — some insurers offer 5% to 15% off your premium for qualifying.
Do buy a separate Medicare Part D drug plan alongside your Medigap policy — Medigap stopped covering prescription drugs after 2005.
Do contact your State Health Insurance Assistance Program (SHIP) for free, unbiased counseling before making a decision.
Don’t wait past your 6-month window thinking you can always enroll later — medical underwriting can deny you coverage permanently.
Don’t buy a Medigap plan if you already have a Medicare Advantage plan — it is generally illegal for an insurer to sell you one while you have Part C coverage.
Don’t assume all states work the same — Massachusetts, Minnesota, and Wisconsin have entirely different Medigap structures.
Don’t pay for benefits you don’t need — if you never travel abroad, you don’t need foreign travel emergency coverage, and a plan without it may cost less.
Don’t forget that Medigap covers one person only — spouses must each purchase their own separate policy.
Step-by-Step: How to Buy a Medigap Policy
Step 1 — Confirm you have Original Medicare. You must be enrolled in both Part A and Part B before you can buy a Medigap policy. If you only have Part A, you are not yet eligible.
Step 2 — Decide which plan letter fits your needs. Review the benefits chart and determine how much out-of-pocket risk you’re comfortable with. Plan G offers near-total protection. Plan N saves on premiums but adds small copays. Plans K and L offer the lowest premiums with cost-sharing up to an annual cap.
Step 3 — Compare premiums from multiple carriers. Visit Medicare’s plan finder tool or call your SHIP to get quotes. Ask each company about their pricing method (community-rated, issue-age, or attained-age).
Step 4 — Ask about discounts and rate history. Request the company’s premium increase history for the past 3 years. Ask about household discounts, non-smoker discounts, and auto-pay discounts.
Step 5 — Submit your application during Open Enrollment. Time your application so your Medigap coverage begins during your 6-month Open Enrollment window. If you’re outside this window, confirm whether you have a guaranteed issue right before applying.
Step 6 — Enroll in a separate Part D drug plan. Medigap does not include prescription drug coverage. Choose a Medicare Part D plan that covers your medications at the lowest total cost.
Key Entities and Organizations You Should Know
Centers for Medicare & Medicaid Services (CMS) is the federal agency that runs Medicare. CMS sets the rules for Medigap standardization, determines annual deductibles and coinsurance amounts, and publishes official cost data each year.
National Association of Insurance Commissioners (NAIC) works with CMS to develop the official Medigap guide. NAIC also sets model regulations that states use to govern Medigap sales practices and consumer protections.
State Insurance Departments regulate Medigap sales in each state. They handle complaints against insurance companies, enforce rate-filing requirements, and may provide additional consumer protections beyond federal law.
State Health Insurance Assistance Programs (SHIP) offer free, one-on-one counseling to Medicare beneficiaries. SHIP counselors help you compare plans, understand your rights, and file complaints. You can find your local SHIP at shiphelp.org.
Private insurance companies like Aetna, Cigna, Mutual of Omaha, UnitedHealthcare, Blue Cross Blue Shield, Aflac, and Humana sell Medigap policies. Each company sets its own premiums and decides which plan letters to offer in each state.
2026 Medicare Costs at a Glance (What Medigap Helps Cover)
| Medicare Cost | 2026 Amount |
|---|---|
| Part B standard monthly premium | $202.90 |
| Part B annual deductible | $283 |
| Part A inpatient hospital deductible | $1,736 |
| Part A daily coinsurance (days 61–90) | $434 per day |
| Part A lifetime reserve day coinsurance | $868 per day |
| Skilled nursing facility coinsurance (days 21–100) | $217 per day |
| High-deductible Plan F/G deductible | $2,950 |
| Plan K out-of-pocket limit | $8,000 |
| Plan L out-of-pocket limit | $4,000 |
FAQs
Can I buy a Medigap policy if I’m under 65?
No in most states. Federal law does not require insurers to sell Medigap to people under 65. Some states like New York and Connecticut have laws requiring access for disabled beneficiaries.
Does Medigap cover prescription drugs?
No. Medigap plans sold after 2005 cannot include drug coverage. You need a separate Medicare Part D plan for prescriptions.
Can I switch Medigap plans after I enroll?
Yes, but you may face medical underwriting. Outside your Open Enrollment Period, insurers can deny you or charge more based on health conditions.
Does Medigap work with Medicare Advantage?
No. It is illegal for an insurer to sell you a Medigap policy if you have a Medicare Advantage plan. You must have Original Medicare.
Will my Medigap premium go up every year?
Yes, in most cases. Premiums rise due to inflation and health care costs. Attained-age-rated policies also increase based on your age each year.
Can my Medigap insurer cancel my policy?
No, as long as you pay your premiums. All Medigap policies issued since 1992 are guaranteed renewable regardless of health status.
Is there a penalty for late Medigap enrollment?
No direct penalty, but insurers can use medical underwriting to deny coverage or charge higher premiums if you apply outside your Open Enrollment Period.
Do I still need to pay my Part B premium with Medigap?
Yes. Medigap is extra insurance on top of Original Medicare. You must continue paying the $202.90 monthly Part B premium in 2026.
Can my spouse use my Medigap policy?
No. Each person must buy their own individual Medigap policy. Medigap coverage applies to one person only.
Does Medigap cover dental and vision?
No. Medigap plans do not cover dental, vision, hearing aids, or glasses. You need separate insurance for those services.
Can I use Medigap when traveling outside the U.S.?
Yes, if you have Plans C, D, F, G, M, or N. These plans cover 80% of foreign travel emergency care up to plan limits.
Is Plan G better than Plan F?
Yes, for most people. Plan G premiums are lower, and the only extra cost is the $283 Part B deductible — saving most enrollees over $1,000 annually.
What is Medicare SELECT?
Yes, it exists. Medicare SELECT is a Medigap policy that requires you to use specific hospitals and doctors for full benefits but charges lower premiums.
Do all insurance companies sell every Medigap plan?
No. Each company chooses which plans to sell. Federal law only requires them to offer Plan A if they sell any Medigap plan in your state.
Can I buy Medigap if I have a pre-existing condition?
Yes, during your 6-month Open Enrollment Period. The insurer cannot deny you or charge more. Outside that window, underwriting applies.
Related reading
- How Does Medicare Part D Work (w/Examples) + FAQs
- What Does Medicare Part B Cover for Seniors? (w/Examples) + FAQs
- Should I Enroll in Medicare Part D? (w/Examples) + FAQs
- Are Supplemental Insurance Plans Worth It? (w/Examples) + FAQs
- Do I Really Need Supplemental Insurance with Medicare? (w/Examples) + FAQs
- Does Cigna Offer Supplemental Benefits? (w/Examples) + FAQs
- Is Nationwide Long-Term Care Insurance Worth It? (w/Examples) + FAQs