Last updated: June 2026 • 11 min read
Original Medicare (Parts A and B) covers about 80% of your healthcare costs — leaving you exposed to significant out-of-pocket expenses including deductibles, copays, and coinsurance that can add up to thousands per year. Medicare Supplement insurance (also called Medigap) fills those gaps.
But with 10 standardized plan types (A through N) and dozens of insurance companies selling them, choosing the right Medigap plan is genuinely confusing. This guide makes it simple.
Medigap is private health insurance that works alongside your Original Medicare (Parts A and B). It does NOT replace Medicare — it supplements it by paying some or all of your out-of-pocket Medicare costs.
Key facts:
Because Medigap plans are federally standardized, the benefits below are the same no matter which insurer sells the plan. The table shows which gaps in Original Medicare each plan letter fills. The specific deductible and copay dollar amounts referenced are set by Medicare and adjusted each year, so always check Medicare.gov for the current figures.
| Benefit | Plan A | Plan G | Plan N | Plan K | Plan L |
|---|---|---|---|---|---|
| Part A coinsurance & hospital costs (up to 365 days) | ✓ | ✓ | ✓ | 50% | 75% |
| Part B coinsurance or copayment | ✓ | ✓ | ✓* | 50% | 75% |
| Blood (first 3 pints) | ✓ | ✓ | ✓ | 50% | 75% |
| Part A hospice care coinsurance | ✓ | ✓ | ✓ | 50% | 75% |
| Skilled nursing facility coinsurance | ✗ | ✓ | ✓ | 50% | 75% |
| Part A (hospital) deductible | ✗ | ✓ | ✓ | 50% | 75% |
| Part B (medical) deductible | ✗ | ✗ | ✗ | ✗ | ✗ |
| Part B excess charges | ✗ | ✓ | ✗ | ✗ | ✗ |
| Foreign travel emergency | ✗ | 80% | 80% | ✗ | ✗ |
*Plan N: You pay a copay (up to a set dollar limit) for office visits, and a copay for ER visits that don't result in inpatient admission. Check Medicare.gov for the current copay limits.
The exact benefit details and the dollar amounts above (deductibles and copays) change from year to year and are set by Medicare, not by individual insurers. You can confirm the current standardized benefits and amounts for each plan letter on the official Medicare site at Medicare.gov before you compare quotes.
Plan F was historically the most comprehensive Medigap plan — it covered everything, including the Part B deductible. However, it's no longer available to anyone who became eligible for Medicare on or after January 1, 2020. If you already had Plan F before that date, you can keep it. For new enrollees, the practical choice is between Plan G and Plan N.
Plan G covers everything Plan F did except the annual Part B deductible. That single deductible is the only out-of-pocket gap you're responsible for under Plan G. Because Plan F is no longer available to new enrollees, Plan G has become the most comprehensive plan most new beneficiaries can buy. Where both were offered, Plan G premiums were often lower than Plan F, since Plan F policyholders are an older, closed group — but the actual difference depends entirely on your insurer and state.
Best for: Beneficiaries who want predictable costs, the most complete coverage available to new enrollees, and the freedom to see any provider who accepts Medicare.
Plan N is similar to Plan G but with two differences: you pay a copay for office visits and for ER visits that don't lead to admission, and Plan N doesn't cover Part B excess charges (the extra amount non-participating doctors are allowed to charge above the Medicare-approved rate). In exchange for taking on those small out-of-pocket costs, Plan N typically carries a lower monthly premium than Plan G.
Best for: Relatively healthy beneficiaries who don't visit doctors frequently and don't mind paying small copays in return for a lower premium.
Premiums for both plans vary widely by insurer, your age, where you live, and how the company prices its policies, so the only way to know what you would actually pay is to compare current quotes. The official Medigap comparison tool at Medicare.gov lets you see the plans and participating companies available in your ZIP code.
Because the benefits within a given plan letter are identical across insurers, the main thing that varies between companies is price. Two people the same age, buying the same Plan G in the same state, can be quoted very different premiums by different carriers. Rather than relying on a generic price chart, it's far more reliable to pull live quotes for your own ZIP code and age. How much a Medigap plan costs depends on several factors:
Insurers are allowed to price the same standardized plan in one of three ways. Understanding which method a company uses matters more for your long-term cost than the starting premium:
When you compare quotes, ask each insurer which method it uses and request its recent rate-increase history. A low starting premium on an attained-age policy can end up costing more than a slightly higher community-rated one a decade later.
Because every insurer must offer the same federally standardized benefits within a given plan letter, there is no "secret" company with better coverage — a Plan G is a Plan G everywhere. What does differ between carriers is what you should actually compare:
Many large, well-known carriers — including AARP/UnitedHealthcare, Mutual of Omaha, Cigna, Humana, Blue Cross Blue Shield affiliates, and others — sell Medigap policies, but availability and price differ by state. To see exactly which companies offer each plan where you live and to compare them side by side, use the official tool at Medicare.gov. You can also check an insurer's complaint record through your state's Department of Insurance and review industry resources from the National Association of Insurance Commissioners (NAIC).
This is the most important timing decision in Medicare. You have a 6-month Medigap Open Enrollment Period that begins the month you're both age 65 and enrolled in Medicare Part B.
During this window:
Apply during your Open Enrollment window, even if you're not sure you need Medigap now. Once the window closes, you may be locked out if you develop a health condition.
Many new Medicare beneficiaries confuse Medigap with Medicare Advantage (Part C). They're fundamentally different:
| Medigap | Medicare Advantage | |
|---|---|---|
| Works with | Original Medicare (A+B) | Replaces Original Medicare |
| Doctor choice | Any Medicare provider in US | Network limited in most plans |
| Premium | Separate monthly premium, in addition to your Part B premium | Often low or $0 premium (but the Part B premium is still required) |
| Out-of-pocket risk | Very low (predictable) | Higher (copays, deductibles) |
| Prescription drugs | Not included (need Part D) | Usually included |
| Extra benefits | None beyond Medicare | Often includes dental, vision, hearing |
| Best for | Frequent healthcare users; want predictability | Healthy beneficiaries; tight budgets |
Yes, but outside of guaranteed issue periods you'll need to pass medical underwriting. If your health has declined, you may be denied or charged more. This is why enrolling in the best plan during Open Enrollment is critical.
No. For drug coverage, you need a separate Medicare Part D plan. When you enroll in Medigap, also shop for a Part D prescription drug plan.
There is no single "best" plan for everyone. Plan G is the most comprehensive option available to new enrollees and works well for people who want predictable costs and the freedom to see any Medicare provider nationwide. For healthier beneficiaries who are comfortable with small copays, Plan N usually offers similar coverage for a lower premium. The right choice depends on your health, how often you use care, and the prices available where you live — so compare current quotes before deciding.
For most new Medicare enrollees, a comprehensive plan like Plan G is a sensible starting point — but the single most important step is to shop during your 6-month Medigap Open Enrollment window, when insurers must accept you regardless of health. Compare premiums for the same plan letter from several insurers, ask about each company's pricing method and recent rate-increase history, and confirm the current benefit amounts on Medicare.gov before committing.
Medigap typically costs more in monthly premiums than Medicare Advantage, but it delivers something a network-based plan generally cannot: the freedom to see any doctor in the country who accepts Medicare, with predictable, low out-of-pocket costs for covered services. Which path is right for you depends on your budget, health, and how much you value that flexibility.
For related coverage decisions, see our guides to health insurance when you don't have a job, term life insurance, and the essentials of home insurance.
Editorial note — TopInsuranceGuide Editorial Team
This guide is general consumer information, compiled and kept up to date from public and official sources such as Medicare.gov. It is not individualized insurance, financial, or medical advice. Medicare rules, plan benefits, and premiums change every year and vary by person and by state, so the specifics that apply to you may differ from what's described here. Before choosing a Medigap plan, get personalized quotes, confirm current details on Medicare.gov, and consult a licensed insurance agent or your state's Department of Insurance. Learn more about how we work.