Learn About Medigap Coverage Options Guide

What Medigap Insurance Covers and How It Works

Medigap, also called Medigap or Medicare Supplement Insurance, is a type of private insurance designed to work alongside Original Medicare. Original Medicare—which includes Part A (hospital coverage) and Part B (medical coverage)—does not cover all health care costs. Patients are responsible for paying deductibles, coinsurance amounts, and copayments. Medigap policies are sold by private insurance companies and help pay these out-of-pocket costs that Original Medicare leaves behind.

When you have both Original Medicare and a Medigap policy, here is how the payment process works: You pay your monthly Medigap premium to the private insurance company. When you receive medical care, Medicare processes the claim first. Then your Medigap policy steps in and pays a portion of the remaining costs, depending on which plan you choose. The insurance company pays its share directly to the health care provider or reimburses you, depending on the arrangement.

Medigap policies are standardized by the federal government. This means that a Plan G offered by one insurance company must cover the same services as a Plan G from another company. The main difference between companies is price and customer service quality. Currently, there are ten standard Medigap plans available: A, B, D, G, K, L, M, N, and two high-deductible versions of Plan G and Plan F (in some states).

It is important to understand that Medigap is different from Medicare Advantage (Part C). Medicare Advantage is an alternative to Original Medicare offered by private insurers, while Medigap supplements Original Medicare. You cannot have both at the same time. Medigap also does not cover prescription drugs. For prescription drug coverage, you would need to enroll in a separate Part D plan.

Practical takeaway: Medigap reduces your out-of-pocket costs when you use Original Medicare, but you need to understand how it coordinates with Medicare before choosing a plan.

Understanding the Ten Standard Medigap Plans

The ten standard Medigap plans each cover different combinations of services. Plans are labeled with letters and are identical across all insurance companies, making it straightforward to compare prices. Here is what you should know about each plan's basic coverage level:

Plan A: Covers hospital coinsurance and copayments, Part B coinsurance and copayments, blood transfusions, and hospice coinsurance. Does not cover Part B deductible or excess charges.
Plan B: Similar to Plan A but also covers the Part B deductible ($240 in 2024).
Plan D: A middle-range plan that covers most costs except Part B excess charges and some preventive care costs.
Plan G: One of the most popular plans. Covers almost everything Original Medicare does not pay for, except the Part B deductible and excess charges.
Plan K: A lower-cost plan where you pay a percentage of costs until you reach an out-of-pocket limit.
Plan L: Similar to Plan K but with a higher out-of-pocket limit.
Plan M: Covers many costs but requires you to pay the Part B deductible and some coinsurance amounts.
Plan N: Covers most costs but requires copayments for office visits and emergency room visits, and does not cover excess charges.

Two high-deductible versions of Plan G and Plan F (in limited states) are also available. These plans have much lower monthly premiums but require you to pay a higher annual deductible ($2,940 in 2024) before the plan begins covering costs. High-deductible plans may be suitable if you are in good health and do not expect to use many medical services.

Practical takeaway: Plan G and Plan N are currently the most widely offered and popular plans. Comparing what each plan covers helps you choose based on your expected medical needs and budget.

When You Can Enroll in Medigap and Why Timing Matters

Unlike some other Medicare programs, Medigap enrollment is not limited to specific times of the year. You can apply to purchase a Medigap policy at any time. However, the time when you first become eligible for Medicare is especially important because of something called "guaranteed issue" rights.

Guaranteed issue means that insurance companies must sell you a Medigap policy without asking health questions or charging more because of pre-existing conditions. You have guaranteed issue rights for six months from the date you turn 65 and enroll in Medicare Part B (or the date you become eligible for Medicare if you are under 65). During this six-month window, you can purchase almost any Medigap plan available, and insurers cannot deny you or charge more based on your health.

If you wait to purchase Medigap coverage after this six-month period ends, insurance companies may ask detailed health questions. They can refuse to sell you a policy, charge higher premiums, or exclude coverage for pre-existing conditions. This makes enrolling during your initial eligibility window financially and practically advantageous. The specific plans available to you during guaranteed issue depend on which state you live in.

Another important timing consideration involves Medicare Part B. If you delay enrolling in Part B and later sign up, your guaranteed issue period may restart in some situations. This rule is complex and varies by circumstance, so reviewing the specific rules for your situation is important.

Practical takeaway: Enrolling in Medigap within six months of turning 65 and signing up for Part B provides protection against medical underwriting and higher premiums based on health status.

Comparing Costs and Finding Affordable Plans

Medigap premiums vary significantly between insurance companies and by plan type. According to data from the Centers for Medicare & Medicaid Services, Plan G premiums can range from around $120 to $300 or more per month depending on the insurer and your state. Plan N, which is slightly less comprehensive, often costs $30 to $60 less per month. Plan A, which covers fewer services, typically costs $80 to $150 monthly. These prices change annually and differ based on where you live.

Insurance companies set premiums using one of three methods: community rating (everyone pays the same), issue-age rating (premiums are based on your age when you purchase), or attained-age rating (premiums increase as you get older). Attained-age rating policies tend to have lower initial premiums but increase more steeply over time. Community-rated policies cost more initially but remain more stable.

To compare costs, you can gather quotes directly from insurance companies operating in your state. Medicare.gov provides a Medigap plan comparison tool that shows available plans and prices from different insurers. Some states also have health insurance assistance programs that can provide information about local plans and costs. When comparing, look at both the monthly premium and what services the plan covers, since a cheaper plan might require higher out-of-pocket costs when you need care.

Medicare allows you to change Medigap plans once per year during the annual enrollment period (October 15 through December 7), even if you switch to a different insurance company. You can also switch plans at any time if you move to a different state. These options provide flexibility if you find a better price or plan after your initial purchase.

Practical takeaway: Comparing quotes from multiple insurers and understanding how premium pricing works can help you find coverage that fits your budget while meeting your health care needs.

State Variations and Special Circumstances

Medigap rules and available plans vary by state. Most states offer all ten standard plans, but three states (Massachusetts, Minnesota, and Wisconsin) have different plan structures set by state law. In Massachusetts, plans are labeled Standard, Enhanced, and Premium rather than by letters. Minnesota and Wisconsin also have unique plan designs. If you live in or move to one of these states, the plans may not be directly comparable to standard Medigap plans.

Certain situations may affect your Medigap options. If you are under 65 and eligible for Medicare due to disability or end-stage renal disease, Medigap