Medicare Supplement plans fill in the gaps in coverage left behind by Medicare Parts A and B, such as plan deductibles, coinsurance, and copayments. These plans may also offer additional coverage that Medicare Parts A and B does not offer, such as vision, dental, or coverage outside of the U.S.
To be eligible to enroll in a Medicare Supplement plan you must be enrolled in both Medicare Part A and Part B. If you are under 65 and are enrolled in Medicare Parts A and B due to a disability, you may have the option of enrolling in a Medicare Supplement plan.
Each Medicare Supplement plan type offers its own set of benefits, which could include Medicare Part A and Part B coinsurance, copayments, and deductibles, the first three pints of blood used in a medical procedure, Skilled Nursing Facility (SNF) care coinsurance, hospital costs up to an additional 365 days after Medicare Parts A and B benefits are used up, and more.
The best time to enroll in a Medicare Supplement plan is during the Medicare Supplement Open Enrollment Period. Once you are both over 65 and enrolled in Medicare Part B, you have a 6-month period to enroll in a Medicare Supplement plan of your choosing without being subject to medical underwriting. After this 6-month period, you can still enroll in any plan you wish, but private insurance companies can then use medical underwriting to deny you coverage or increase your plan premium based on any pre-existing conditions.
There are 10 different types of Medicare Supplement plans, labeled with the letters A through N. Each of these plans offers its own benefits, but the coverage for each lettered plan must be the same regardless of location or who is offering the plan. For example, Plan F in New York must offer the same benefits as Plan F in California. Not all of the lettered plans are offered in all parts of the country and plans are completely different in Massachusetts, Minnesota, and Wisconsin.
Medicare Supplement plans are offered through private insurance companies that require plan premiums to provide coverage. These premiums can be set in one of three different ways: community-rated, issue-age-rated, and attained-age-rated. While premium costs may appear low when you first enroll, they could change over time, so it is important to research how the plan premiums are set.