Original Medicare (Parts A and B) covers a broad range of medical services, but it does not pay 100% of your costs. You are responsible for deductibles, coinsurance, and copays that can add up quickly, especially if you are hospitalized or need frequent specialist care. A Medicare Supplement plan, also called Medigap, is private health insurance designed to fill those gaps. This article explains exactly how Medigap works, which plans are available in 2026, who needs one, and when to enroll.
2026 Cost Gaps Medigap Can Fill
Part A hospital deductible: $1,676 per benefit period. Part B deductible: $257 per year. Part B coinsurance: 20% of all outpatient costs with no cap. Skilled nursing facility coinsurance: $209.50/day for days 21-100.
What Is a Medicare Supplement (Medigap) Plan?
A Medicare Supplement plan is a standardized private insurance policy that works alongside Original Medicare Parts A and B. When Medicare pays its share of an approved service, your Medigap policy pays some or all of the remaining costs, depending on which plan you have. Medigap does not replace Medicare; it supplements it. You must be enrolled in both Part A and Part B to purchase a Medigap policy.
Medigap plans are sold by private insurance companies but are federally standardized in 47 states. That means a Plan G from one carrier offers the exact same benefits as a Plan G from any other carrier. The only differences are the premium, the pricing method (how premiums change over time), and the carrier's customer service reputation. Massachusetts, Minnesota, and Wisconsin have their own standardized Medigap structures.
What Does a Medigap Plan Cover?
All Medigap plans cover the same core benefits but differ in how much of your cost-sharing they pick up. For most people becoming eligible for Medicare in 2026, the choice comes down to two plans: Plan G and Plan N. Together they account for the vast majority of new Medigap enrollments. The table below compares what each covers. For a full comparison of all available plans, see our Choosing a Medigap Policy guide.
| Benefit | Plan G | Plan N |
|---|---|---|
Part A hospital coinsurance (up to 365 extra days) | Covered | Covered |
Part A hospital deductible ($1,676 per benefit period) | Covered | Covered |
Part B coinsurance (20% of outpatient costs) | Covered | Covered (with copays) |
Part B deductible ($257/year) | Not covered | Not covered |
Part B excess charges | Covered | Not covered |
Skilled nursing facility coinsurance (days 21-100) | Covered | Covered |
Blood (first 3 pints) | Covered | Covered |
Foreign travel emergency (80%, up to plan limits) | Covered | Covered |
Office visit copay | None | Up to $20 |
Emergency room copay (no admission) | None | Up to $50 |
Plans C and F are no longer available to people who became eligible for Medicare on or after January 1, 2020. Plan G is the most comprehensive plan available to new enrollees.
Plan G vs. Plan N: The Two Most Popular Plans in 2026
For most new Medicare enrollees in 2026, the choice comes down to Plan G and Plan N. Plan G is the most comprehensive plan available to new enrollees. It covers everything except the Part B deductible ($257/year). Once you meet that deductible, Medicare and Plan G together pay 100% of all Medicare-approved costs, including Part B excess charges. Plan G is ideal if you want complete predictability.
Plan N has a lower monthly premium than Plan G but requires copays of up to $20 for office visits and up to $50 for emergency room visits that do not result in inpatient admission. Plan N also does not cover Part B excess charges, meaning you could owe more if your doctor charges above the Medicare-approved amount. Plan N works well for people who are generally healthy and want lower premiums in exchange for modest cost-sharing.
Plan G vs. Plan N: Quick Rule of Thumb
If the annual premium difference between Plan G and Plan N is less than $300-$400, Plan G is usually the better value. If the difference is larger and you are in good health, Plan N can save money over time.
Who Needs a Medicare Supplement Plan?
A Medigap plan is not right for everyone, but it is a strong fit for certain groups. You are a good candidate for Medigap if you travel frequently and want coverage outside your home area, if you have chronic conditions that require regular specialist visits or hospitalizations, if you want to see any doctor or specialist in the country without a referral, or if you are on a fixed income and need predictable, capped healthcare costs.
| Situation | Medigap Fits Well? | Why |
|---|---|---|
Frequent hospitalizations or surgeries | Yes | Eliminates the $1,676 Part A deductible per benefit period |
Chronic conditions with regular specialist visits | Yes | Covers the 20% Part B coinsurance with no annual cap |
Travel frequently or split time between states | Yes | Accepted by any Medicare provider nationwide; Plans D, G, M, N cover foreign travel emergencies |
Generally healthy, low healthcare use | Maybe | Lower-premium Plan N or Medicare Advantage may cost less overall |
Need extra benefits (dental, vision, hearing) | No | Medigap does not cover these; Medicare Advantage plans often do |
Tight monthly budget, prefer low premium | Maybe | Medicare Advantage plans often have $0 premiums but have networks and prior auth requirements |
Medigap vs. Medicare Advantage: Key Differences
Medicare Advantage (Part C) is an alternative to Original Medicare that bundles Parts A, B, and usually D into one plan. It often includes extra benefits like dental, vision, and hearing. However, Medicare Advantage plans use networks and may require referrals or prior authorization. Medigap works with Original Medicare and gives you access to any provider in the country who accepts Medicare, with no networks or referrals required.
| Feature | Medigap + Original Medicare | Medicare Advantage |
|---|---|---|
Provider network | Any Medicare provider nationwide | In-network providers only (except emergencies) |
Out-of-pocket maximum | Effectively $0 with Plan G after deductibles | Varies by plan; max $9,350 in-network (2026) |
Drug coverage | Separate Part D plan required | Usually included |
Extra benefits (dental, vision, hearing) | Not included | Often included |
Monthly premium | $100-$300+ depending on plan and age | Often $0-$50 |
Referrals required | No | Often yes (HMO plans) |
Prior authorization | Rare | Common for procedures and drugs |
Best for | Predictable costs, frequent medical use, travel | Low premium, extra benefits, generally healthy |
When Should You Enroll in a Medigap Plan?
The best time to enroll in a Medigap plan is during your Medigap Open Enrollment Period (OEP). This is a one-time, six-month window that begins the month you are both age 65 or older and enrolled in Medicare Part B. During this window, you have guaranteed issue rights: insurance companies cannot deny you coverage, charge you more, or impose waiting periods based on your health history or pre-existing conditions.
Missing the Open Enrollment Window Has Consequences
If you apply for Medigap outside your OEP, insurers in most states can use medical underwriting. This means they can charge higher premiums, exclude pre-existing conditions for up to 6 months, or deny your application entirely. Some states offer additional protections, but most do not.
Many carriers allow you to apply for a Medigap plan three to six months before your Part B effective date so your coverage starts on day one. The plan will not activate before your Part B start date, but applying early locks in your rate and avoids a gap in coverage. Outside the OEP, you may still qualify for guaranteed issue rights if you experience a qualifying life event, such as losing employer coverage or moving out of a Medicare Advantage plan's service area.
How Much Does a Medigap Plan Cost in 2026?
Medigap premiums vary widely based on your age, gender, tobacco use, location, the plan letter you choose, and the carrier's pricing method. A 65-year-old non-smoking woman in a mid-cost state might pay $100-$150/month for Plan N and $130-$200/month for Plan G. Premiums are generally higher for men and increase with age, especially under attained-age pricing.
| Pricing Method | How It Works | Premium Trend Over Time |
|---|---|---|
Community-rated | Same premium for all enrollees regardless of age | Increases only with general inflation; best long-term value |
Issue-age rated | Premium based on your age when you first enroll; does not increase as you age | Moderate increases over time |
Attained-age rated | Premium based on your current age and increases each year as you get older | Lowest starting premium but highest long-term cost |
Community-rated and issue-age plans tend to cost more upfront but less over a 10-20 year period compared to attained-age plans.
In addition to your Medigap premium, you will still pay your Part B premium ($185/month standard in 2026) and, if you want drug coverage, a separate Part D premium (average $34.50/month in 2026). These costs are separate from your Medigap plan.
Frequently Asked Questions
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