Older Americans have important decisions to make each year regarding their Medigap and Medicare coverage. Medicare open enrollment runs from October 15 to December 7 every year.
The best time to buy a policy is during your Medigap open enrollment period. Under federal law, you get a six-month Medigap open enrollment period that starts the first month you have Medicare Part B and you’re 65 or older.
After this period, you may not be able to buy a Medigap policy, or it may cost more. Your Medigap open enrollment period is a one-time opportunity and doesn’t repeat annually.
Why you need Medigap
Original Medicare provides a number of great benefits to enrollees, but this coverage does have some gaps. For instance, Part B will cover only 80% of your medical expenses, after you hit the deductible, with no out-of-pocket maximum. That means you could be on the hook for a significant bill if you become gravely ill. Part A will only pay for the first 60 days you spend in the hospital, again after a deductible is met, before you must start paying co-insurance.
Because of this, many beneficiaries choose to enroll in either a Medicare Advantage plan or a supplemental policy to help cover those costs. (For more on Medicare Advantage, see Is a Medicare Advantage Plan Right for You?)
What is Medigap insurance?
If you decide to go with a Medicare supplement policy (or more commonly called Medigap), you then must select which plan you want. Medigap plans are administered by private insurance companies. These plans come in 10 letter designations (A through D; F; G; and K through N). All plans with the same letter have the same coverage, but prices can vary based on the insurance company.
The 10 different types of Medigap insurance
Which plan is right for you depends on your personal preferences and how much medical care you expect to need that year. The plans offer a range of benefits with some covering many of your Medicare costs while others require more cost sharing.
Plans C and F. Plan F has been the most popular because of its generous benefits. It covers the Medicare Part A hospital deductible and co-payments, the Part B deductible, and some emergency care outside the U.S.
Plan C covers many of the same benefits as Plan F, except it won’t pay for the Part B excess charge. This happens when a provider charges Medicare more than the amount approved by the program. The beneficiary is then responsible for that excess amount.
However, Plans C and F are no longer available to those who became eligible for Medicare after Jan. 1, 2020. Medigap plans are no longer allowed to cover Part B deductibles. Since both of these plans paid for that, insurance companies can no longer offer them to new beneficiaries. Those already enrolled in those plans can keep that insurance. However, premiums are likely to rise as these plans can no longer accept new enrollees.
If you were considering Plan F, then take a look at Plan G. It provides the same coverage as Plan F except for the Part B deductible.
Plan G. Due to the phasing out of the popular Medigap Plan F, Plan G is now the plan of choice for many. Plan F is considered the top-of-the-line Medigap policy and Plan G comes closer than any other policy in matching Plan F's coverage. The glaring difference is that Plan G does not cover the Part B deductible, which is $257 in 2025.
Like Medigap Plan F, Plan G also covers “excess charges.” Doctors who don’t accept the full Medicare-approved amount as full payment can charge you up to 15% more than the Medicare-approved amount for services or procedures. (Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island and Vermont have banned excess charges.)
Plan D. Plan D is similar to Plan G as it covers more than most Medigap plans, but unlike Plan G it goes not cover excess charges.
Plan M. Plan M is nearly identical to Plan D, but while Plan D covers the full Medicare Part A deductible, Plan M covers only half.
Plans K and L. Medicare Supplement Plan K and Plan L are cheaper than other in Medigap policies. These two plans have lower monthly basis since you’ll also share the cost of coinsurance for your Plan K and L bills (50 percent for K and 25 percent for L) up to an annual out-of-pocket limit.
Your cost-sharing ends once you reach that annual Plan K or L out-of-pocket limit. The 2025 out-of-pocket (OOP) limits for Medigap plans K and L are $7,220 and $3,610, respectively.
If you don’t anticipate having many doctors’ visits, consider Plan N, which usually has lower premiums in return for some cost sharing.
Plan N. Plan N is the third most popular plan type, covering about 10% of all Medigap members. Plan N has lower premiums than other popular options like Plan G and Plan F. Plan N pays 100% of the costs of Part B services, except for copayments for some office visits and some emergency room visits.
In 2025, Plan N copays are up to $20 for doctor visits and up to $50 for emergency room visits after the Part B deductible is met. Plan N also covers the Part A deductible, which is $1,676 in 2025. Plan N doesn't cover Part B excess charges.
Plans A and B. Plan A is ideal if you want more coverage than Medicare Parts A and B but don’t plan to use a lot of healthcare services. Plan A includes only the basics for Medigap plans — the benefits that every Medigap plan covers.
Plan B provides the same benefits as Plan A, plus a little more coverage for hospitalization by paying the Part A deductible. The premiums are lower for Plans A and B, and while you won’t pay for extra coverage you might not use — you may have some occasional extra out-of-pocket costs.
High deductible plans. Medigap Plans F and G can be sold with a high deductible option. The high-deductible version of Plan F is only available to those who signed up for Medicare before January 1, 2020. High-deductible Plan G is available to individuals who are new to Medicare on or after January 1, 2020. (Before June 1, 2010, Medigap Plan J could also be sold with a high deductible.)
The annual deductible amount for these three plans is $2,870 in 2025. The deductible amount for the high deductible version of plans G, F and J represents the annual out-of-pocket expenses (excluding premiums) that you must pay, at which point your coverage will kick in.
Help choosing the right Medigap plan
Medicare provides a chart that outlines what each Medigap plan covers. Medicare also provides a tool that allows you to compare different Medigap plans available in your area. Enter your zip code, age, gender and whether you smoke, and Medicare will provide a price range for each available plan and a list of insurers who offer the coverage.
