Original Medicare pays a large portion of approved medical expenses—but not everything. Beneficiaries may still be responsible for hospital deductibles, copayments and generally 20% of Medicare-approved outpatient costs. Original Medicare also has no annual out-of-pocket limit.
Medicare Supplement Insurance, commonly called “Medigap,” helps pay some of these remaining expenses.
What is Medicare Supplement Insurance?
Medigap is private insurance designed to work alongside Original Medicare:
- Medicare pays its share of a Medicare-approved medical bill.
- The Medigap policy pays according to its benefits.
- The patient pays any amount that remains.
To purchase Medigap, a person generally must have both Medicare Part A and Part B. Medigap does not replace Medicare—it supplements it.
Important distinctions:
- Medigap is not Medicare Advantage.
- A person cannot use Medigap and Medicare Advantage together.
- Each spouse needs a separate Medigap policy.
- Beneficiaries continue paying their Medicare Part B premium in addition to the Medigap premium.
- Medigap policies sold today do not include prescription-drug coverage. A separate Medicare Part D plan may be needed. Learn how Medigap works from Medicare.
Do not confuse Medigap Plan D with Medicare Part D:
- Medigap Plan D helps with medical cost-sharing.
- Medicare Part D covers prescription drugs.
Are Medigap plans standardized?
Yes. In most states, Medigap plans are standardized by letters: A, B, D, G, K, L, M and N, along with Plans C and F for certain older Medicare beneficiaries.
For example, Plan G from one insurance company must provide the same standardized medical benefits as Plan G from another company. The premiums, discounts, customer service and history of rate increases can be different.
Therefore, consumers should compare the same letter plan among several companies. A higher premium does not necessarily mean better medical coverage.
Massachusetts, Minnesota and Wisconsin standardize Medigap policies differently. Not every insurer offers every plan. Medicare explains Medigap pricing here.
Important Medicare costs in 2026
Before comparing Medigap plans, retirees should understand these two Medicare deductibles:
- Part A hospital deductible: $1,736 for each benefit period—not necessarily once per calendar year.
- Part B annual deductible: $283.
After the Part B deductible, Original Medicare generally pays 80% of the Medicare-approved amount for covered outpatient services, while the beneficiary pays 20%. Original Medicare does not place an annual limit on that 20% responsibility. See Medicare’s 2026 costs.
None of the Medigap plans discussed below—A, B, D, G, K, L, M and N—covers the $283 Part B deductible. Beneficiaries pay it themselves.
Comparison of Medigap plans
| Standard benefit | A | B | D | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|
| Part A hospital coinsurance and up to 365 additional hospital days | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| Part B coinsurance or copayments | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% with certain copayments |
| First three pints of blood | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% |
| Part A hospice coinsurance or copayments | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% |
| Skilled nursing facility coinsurance | No | No | 100% | 100% | 50% | 75% | 100% | 100% |
| Part A hospital deductible | No | 100% | 100% | 100% | 50% | 75% | 50% | 100% |
| Part B annual deductible | No | No | No | No | No | No | No | No |
| Part B excess charges | No | No | No | 100% | No | No | No | No |
| Foreign-travel emergency benefit | No | No | 80% | 80% | No | No | 80% | 80% |
| 2026 Medigap out-of-pocket limit | None | None | None | None | $8,000 | $4,000 | None | None |
“None” in the out-of-pocket-limit row does not necessarily mean the plan provides less protection. Plans such as G cover most Medicare cost-sharing directly and therefore do not use the same cost-sharing limit structure as Plans K and L. See Medicare’s official comparison chart.
Understanding each plan
Plan A: Basic protection
Plan A covers the basic Medigap benefits, including hospital coinsurance, Part B coinsurance, hospice cost-sharing and the first three pints of blood.
Advantages:
- Usually simpler than more comprehensive plans.
- May have a lower premium.
- Covers the potentially unlimited 20% Part B coinsurance for Medicare-approved services.
Disadvantages:
- Does not pay the Part A hospital deductible.
- Does not cover skilled nursing facility coinsurance.
- No foreign-travel emergency benefit.
- Does not cover Part B excess charges.
Plan A may suit someone who wants basic protection but is willing to assume more hospital-related expenses.
Plan B: Basic protection plus hospital deductible
Plan B provides Plan A’s benefits and pays 100% of the Part A hospital deductible.
Advantages:
- Better hospital protection than Plan A.
- Pays regular Part B coinsurance.
- Relatively easy to understand.
Disadvantages:
- No skilled nursing facility coinsurance benefit.
- No foreign-travel emergency benefit.
- Does not cover Part B excess charges.
Remember that Medigap Plan B is not Medicare Part B.
Plan D: Broader coverage without excess-charge protection
Plan D covers the Part A deductible, skilled nursing facility coinsurance and foreign-travel emergencies, in addition to the basic benefits.
Advantages:
- Broad hospital and outpatient protection.
- Includes skilled nursing facility coinsurance.
- Includes limited foreign-travel emergency coverage.
Disadvantages:
- Does not cover the Part B deductible.
- Does not cover Part B excess charges.
- Availability and pricing may be less competitive than more widely purchased plans.
Plan G: The most comprehensive option for many new beneficiaries
Plan G covers nearly all standardized Medigap benefits except the annual Part B deductible.
Advantages:
- Pays the Part A hospital deductible.
- Pays Part B coinsurance.
- Covers skilled nursing facility coinsurance.
- Covers Part B excess charges.
- Includes limited foreign-travel emergency coverage.
- Makes Medicare-covered medical expenses relatively predictable.
Disadvantages:
- Premiums may be higher than plans with more cost-sharing.
- The beneficiary still pays the annual Part B deductible.
- Premiums can increase over time.
- It does not cover dental, vision, hearing or prescription drugs.
Some states also offer High-Deductible Plan G. In 2026, the beneficiary must pay $2,950 in Medicare-covered deductibles, copayments and coinsurance before the high-deductible policy begins paying. Its premium is generally lower, but the enrollee assumes more initial financial risk.
Plan K: Lower coverage with a higher spending limit
Plan K pays 50% of several covered expenses, including Part B coinsurance, the Part A deductible and skilled nursing facility coinsurance. It pays 100% of the additional hospital-day benefit.
After the beneficiary reaches the 2026 out-of-pocket limit of $8,000 and pays the Part B deductible, Plan K pays 100% of covered services for the rest of the calendar year.
Advantages:
- Premium may be lower.
- Provides protection against very high Medicare cost-sharing.
- Appropriate for someone comfortable paying a larger share of routine expenses.
Disadvantages:
- The beneficiary pays 50% of many expenses before reaching the limit.
- No foreign-travel emergency benefit.
- No Part B excess-charge coverage.
- The $8,000 limit is substantial.
Plan L: Greater cost-sharing protection than Plan K
Plan L generally pays 75% of covered cost-sharing and has a 2026 out-of-pocket limit of $4,000. After that limit and the Part B deductible are met, it pays 100% of covered services for the rest of the year.
Advantages:
- Lower out-of-pocket limit than Plan K.
- Pays 75% instead of 50% of many expenses.
- May offer a middle ground between premium cost and coverage.
Disadvantages:
- The beneficiary still pays 25% of several expenses before reaching the limit.
- No foreign-travel emergency benefit.
- No Part B excess-charge coverage.
Plan M: Shared hospital deductible
Plan M pays 50% of the Part A hospital deductible but covers regular Part B coinsurance and skilled nursing facility coinsurance.
Advantages:
- Broad coverage for many Medicare gaps.
- Includes limited foreign-travel emergency care.
- Premium may be lower than a more comprehensive plan.
Disadvantages:
- The beneficiary pays half of every applicable Part A hospital deductible.
- Does not cover Part B excess charges.
- The Part A deductible can apply more than once in a year.
Plan N: Broad coverage with modest copayments
Plan N pays most major Original Medicare cost-sharing, but the beneficiary may pay:
- Up to $20 for certain office visits.
- Up to $50 for an emergency-room visit that does not result in inpatient admission.
- Part B excess charges when applicable.
Advantages:
- Broad hospital and outpatient coverage.
- Pays the Part A hospital deductible.
- Includes skilled nursing facility coinsurance.
- Includes limited foreign-travel emergency coverage.
- Premiums may be lower than Plan G.
Disadvantages:
- Office and emergency-room copayments may apply.
- Does not cover Part B excess charges.
- People who visit doctors frequently may accumulate more copayments.
- The beneficiary must pay the Part B deductible.
Plan N can be attractive to relatively healthy retirees who want strong protection while accepting limited cost-sharing.
How does the foreign-travel benefit work?
Plans D, G, M and N provide standardized foreign-travel emergency coverage. After a $250 annual deductible, the plan pays 80% of certain medically necessary emergency expenses outside the United States.
Coverage generally:
- Applies when the emergency begins during the first 60 days of the trip.
- Has a $50,000 lifetime maximum.
- Does not cover routine overseas medical care.
- May require the traveler to pay first and submit documentation for reimbursement.
Because of the lifetime limit and 20% coinsurance, international travelers should still consider separate travel medical and evacuation insurance. See Medicare’s foreign-travel guidance.
What Medigap generally does not cover
Medigap policies generally do not pay for:
- Long-term custodial care or permanent nursing-home residence.
- Routine dental care.
- Routine vision care and eyeglasses.
- Hearing aids.
- Private-duty nursing.
- Prescription drugs in policies sold after 2005.
- Services that Original Medicare does not approve, except specific benefits such as limited foreign-travel emergencies.
A Medigap plan should not be mistaken for long-term-care insurance. Review what Medigap does and does not cover.
Who should consider buying Medigap?
Medigap may be particularly valuable for someone who:
- Chooses Original Medicare instead of Medicare Advantage.
- Wants access to Medicare-participating doctors and hospitals across the country.
- Travels frequently within the United States.
- Has chronic conditions or expects regular medical care.
- Wants more predictable medical expenses.
- Would have difficulty paying repeated hospital deductibles or 20% Part B coinsurance.
- Does not have Medicaid, employer, union, military or retiree coverage that already fills Medicare’s gaps.
- Can afford the monthly premium over the long term.
Does everyone with Medicare need Medigap?
No. Medigap is not necessary or appropriate for everyone.
Someone may not need it if that person:
- Is enrolled in Medicare Advantage.
- Has Medicaid or another program paying Medicare cost-sharing.
- Has strong employer, union, retiree or military supplemental coverage.
- Qualifies for assistance through a Medicare Savings Program.
- Understands and can comfortably assume Original Medicare’s out-of-pocket risk.
However, relying on Original Medicare alone can expose a retiree to substantial costs because there is no annual out-of-pocket maximum for Part A and Part B services.
The decision is therefore not simply, “Do I use doctors often today?” It should also consider whether an unexpected hospitalization, cancer treatment, surgery or lengthy outpatient treatment could create financial difficulty.
The best time to enroll
The most important time to buy Medigap is usually the six-month Medigap Open Enrollment Period. It begins the first month a person is both:
- Age 65 or older, and
- Enrolled in Medicare Part B.
During this one-time federal enrollment period, an insurer generally cannot deny coverage or charge more because of pre-existing health conditions. After it ends, an insurer may use medical underwriting, charge more or deny an application unless the applicant has a guaranteed-issue right or additional protection under state law. Read Medicare’s enrollment rules.
Bottom line
Medigap is optional, but it can provide valuable financial protection for retirees who choose Original Medicare.
For many people, the decision comes down to three general approaches:
- Plan G: higher coverage and fewer unexpected Medicare-approved expenses.
- Plan N: broad coverage with certain copayments and no excess-charge protection.
- Plans K or L: potentially lower premiums in exchange for more cost-sharing, with an annual Medigap out-of-pocket limit.
No single plan is best for everyone. Retirees should compare premiums, expected rate increases, health needs, travel habits, financial resources and existing coverage. Free, unbiased assistance is available through each state’s State Health Insurance Assistance Program, or SHIP.
This article is for general education. Medicare costs and rules can change annually, and state protections may differ.
-Nguyễn Bách Khoa-
Sources for Further Reading
- Medicare Supplement Insurance (Medigap) Overview
Explains what Medigap is, how it supplements Original Medicare, and the basic eligibility requirements.
What’s Medicare Supplement Insurance—Medigap? - Official Medigap Plan Comparison Chart
Compares Plans A–N, including deductibles, coinsurance, skilled nursing facility care, Part B excess charges, and foreign-travel emergency benefits.
Compare Medigap Plan Benefits - What Medigap Covers—and Does Not Cover
Explains covered out-of-pocket costs and exclusions such as long-term care, routine dental and vision care, hearing aids, and prescription drugs.
Learn What Medigap Covers - How Medigap Works with Original Medicare
Covers claim payments, separate policies for spouses, prescription-drug coverage, and the difference between Medigap and Medicare Advantage.
Learn How Medigap Works - Official Medicare Costs for 2026
Lists current Part A and Part B premiums, deductibles, coinsurance, and other Medicare costs.
Medicare Costs in 2026 - Medigap Premiums and Pricing
Explains why premiums for the same standardized plan can vary among insurance companies and how insurers may set their rates.
Get Medigap Costs - When to Buy a Medigap Policy
Explains the six-month Medigap Open Enrollment Period, medical underwriting, guaranteed-issue rights, and the risks of waiting to enroll.
Get Ready to Buy Medigap - Step-by-Step Guide to Buying Medigap
Provides instructions for selecting a plan, comparing insurers and premiums, and completing an application.
How Do I Buy a Medigap Policy? - Find Medigap Plans and Prices by ZIP Code
Medicare’s official search tool for checking available Medigap policies and estimated premiums in a particular area.
Find a Medigap Policy That Works for You - Choosing a Medigap Policy: Official Medicare Guide
A detailed guide covering standardized benefits, enrollment protections, pricing methods, and questions to ask before purchasing a policy.
Choosing a Medigap Policy: A Guide to Health Insurance for People with Medicare - Medicare & You 2026 Handbook
Medicare’s official annual handbook covering benefits, costs, Medigap, Medicare Advantage, Part D, enrollment, and beneficiary rights.
Medicare & You 2026—PDF - Medicare Coverage Outside the United States
Explains limited foreign-travel emergency coverage under certain Medigap plans, including the deductible, 80% benefit, 60-day rule, and lifetime limit.
Medicare Coverage Outside the United States—PDF - Free, Unbiased Medicare Counseling through SHIP
State Health Insurance Assistance Programs provide free Medicare counseling. Find a local program online or call 1-877-839-2675.
Find Your Local SHIP Program - State Insurance Department Directory
Use this directory to verify an insurance company or agent, learn about state-specific Medigap protections, or file a complaint.
NAIC Directory of State Insurance Departments
Medicare costs, deductibles, and enrollment rules may change. Readers should verify current information with Medicare.gov and their state insurance department before enrolling in or changing coverage.