Private insurance companies offer health insurance to cover a variety of out-of-pocket expenses not covered by Original Medicare, Part A and Part B. Called Medicare Supplement plans, these plans are also known by other names, including Medigap and MedSupp.

Generally the best time to sign up for a Medicare Supplement plan is during your Medigap Open Enrollment Period, which starts on the first day of the month that you are both 65 years or older and enrolled in Medicare Part B and lasts for six months. During this time, insurance companies may not reject your application due to a health condition, and can’t require medical underwriting.  Waiting periods may apply.

Medicare Supplement plan types

MedSupp plans may help pay Original Medicare’s out-of-pocket costs, such as copayments, coinsurance, and deductibles. Each type of plan offers a different level of coverage, and is named with a different letter (such as Plan A). In most states, the plans are standardized, so that all plans of the same letter offer the same benefits. In other words, the benefits for a Medicare Supplement Plan D enrollee in Rhode Island are the same for a Medicare Supplement Plan D enrollee in Tennessee. However, the premiums can differ among these private insurance companies and some companies may offer additional benefits.

Massachusetts, Minnesota, and Wisconsin do not offer the standard Medicare Supplement plans. Each of these states has its own unique Medicare Supplement plan offerings.

The table below shows a summary of benefits offered by each of the 10 standard Medicare Supplement plans. In this chart, X means that the service (or item) is 100% covered; a percentage indicates what percent of the service/item is covered; and a blank cell means it is not covered.

Medicare Supplement Plans
Medicare Supplement Benefits A B C* D F* G**** K L M N
Medicare Part A coinsurance and hospital costs up to an additional
365 days after Medicare benefits are exhausted
Medicare Part B copayment or coinsurance X X X X X X 50% 75% X X***
First three pints of blood X X X X X X 50% 75% X X
Medicare Part A hospice care coinsurance or copayment X X X X X X 50% 75% X X
Skilled nursing facility (SNF) care coinsurance X X X X 50% 75% X X
Medicare Part A deductible X X X X X 50% 75% 50% X
Medicare Part B deductible X X
Medicare Part B ‘excess charges’ X X
Foreign travel emergency coverage (up to plan limits) 80% 80% 80% 80% 80% 80%
Medicare Part B preventive care coinsurance X X X X X X X X X X
Out-of-pocket limits apply**


*Plan C and Plan F will not be available to new beneficiaries aging on or after January 1, 2020. However, if you already have Plan C or Plan F, you can keep it.
**Once you reach the out-of-pocket limits (including the Part B deductible), both Medicare Supplement Plans K and L pay 100% of covered services in the above chart for the remainder of the calendar year.
***Plan N pays 100% of the Part B coinsurance costs, except up to $20 copayment for some office visits and up to $50 for emergency room visits. 

****Plan G will offer a high deductible option starting Jan 1, 2020, according to AHIP, America’s Health Insurance Plans. It will not cover the Part B deductible, but the Part B deductible will count towards filling the Plan G high deductible.

More facts about Medicare Supplement plans

  • Although Medicare Supplement plans are standardized by letter, prices may vary across different insurance companies, so you may want to comparison-shop before enrolling.
  • Medicare Supplement plans don’t work with Medicare Advantage If you’re enrolled in a Medicare Advantage plan, a Medicare Supplement plan won’t cover your out-of-pocket costs under the Medicare Advantage plan.
  • Beneficiaries with Medigap plans may want to buy Medicare prescription drug plans, since Medigap plans don’t offer this coverage (Medigap plans sold before 2006 did include prescription drug coverage).
  • Medicare SELECT is a Medigap plan that requires beneficiaries to use hospitals or physicians within its network of healthcare providers to be eligible for full plan benefits. Any of the ten Medigap plan types may be offered in a Medicare SELECT version by an insurance company.
  • Insurance companies offering Medicare Supplement insurance don’t necessarily offer all ten plan types. An insurer may choose to offer only some of the plans.


Medicare Supplement insurance plans are not connected with or endorsed by the U.S. government or the federal Medicare program.