(Medigap, also known as Medicare Supplemental Insurance, is a supplemental insurance policy for people with Original Medicare. Unlike health insurance, which pays for a portion of your medical services and treatments, Medigap covers some or nearly all of your out-of-pocket costs under Original Medicare (Parts A and B together), depending on your plan.
Medicare supplement plans are standardized, meaning each plan of the same letter type covers the same set of costs, in all but three states (Massachusetts, Minnesota and Wisconsin). But unlike Original Medicare or Medicare Advantage, Medigap is managed by each state individually. This can lead to different sets of rules about enrollment and when you can change plans.
Enrolling in Medigap
You can enroll in Medigap within six months of when you first sign up for Medicare Part B. So, for instance, if you enroll in Part B in August, your Medigap Open Enrollment Period would run from August through January.
During this initial signup window you can enroll in any Medigap plan that’s legally sold in your state, and you don’t have to worry about your medical history affecting your application.
If you don’t enroll during that initial 6-month period, you may not be able to get a Medigap plan at all, depending on where you live. This is where state rules come into play.
In some states, Medigap plans are allowed to use medical underwriting to set rates (or deny applications altogether) for people who enroll outside of the initial signup window. This means your medical history could be taken into account, and you might not qualify for Medigap at all.
Other states set limits on what plans can do, so you might still be able to get a plan, but it may cost more or come with more restrictions.
These standard enrollment rules apply to people ages 65 and older. Even though younger people can enroll in Medicare based on disability, federal law doesn’t require insurers to sell Medigap to people under age 65. And not every state does. To date, 33 states have rules requiring insurers to offer at least one kind of Medigap plan to people under 65.
But your options could be limited or even nonexistent. For example, people with end-stage renal disease who are under age 65 may not qualify for Medigap at all.
If you qualify for Medicare and you’re under 65, check with your state health insurance department (or Medicare itself) to see if you can enroll in a Medicare supplement plan as well. There may be different rules for you.
Medigap is available to people with Original Medicare. You have to be enrolled in both parts (A and B) to sign up for Medigap. These plans are standardized in all but three states (Massachusetts, Minnesota and Wisconsin). This means that all plan types cover the same benefits no matter where you buy the plan or who’s selling it. Plan N in Nevada covers the exact same benefits as Plan N in Florida. The difference is in cost. How much you pay for that Plan N depends on where you live.
There are 10 plan types, though two of these (C and F) are no longer offered to new Medicare enrollees as of January 1, 2020. If you qualified for Medicare before then or already had one of these plans beforehand, you may still be able to get Plan C or F. But new enrollees can’t enroll in these plans as of 2020.
Each plan type is labeled with a letter. All Medigap plans cover these basic benefits in whole or in part:
- Part A coinsurance and hospital costs up to an extra 365 days after Medicare benefits are used up
- Part A hospice care coinsurance or copayment
- Part B coinsurance or copayment
- First three pints of blood
Beyond these basics, Medigap policies cover different levels of cost sharing under Original Medicare, highlighted in this table:
* Plans C and F are no longer available to enrollees new to Medicare as of January 1, 2020.
** Plans K and L have an out-of-pocket limit. Once you reach this limit in out-of-pocket spending for the year, the plan will pay for 100% of covered expenses the rest of the year. In 2023, these caps are $6,940 (Plan K) and $3,470 (Plan L). In 2024, the caps increase to $7,060 (K) and $3,530 (L).
*** Plan N will cover the Part B coinsurance in full, except for an office visit copay of up to $20 and an emergency room visit copay (for ER visits that don’t result in inpatient admission) of up to $50
Note: Plans F and G also have a high-deductible version available in some states. This means you’ll pay a deductible ($2,800 in 2024) before your plan pays its share of your costs.
As is the case with most insurance products, the more coverage you get, the higher the premium tends to be. But Medigap can be a bit different in this regard. Popular plans, like Plan G, may actually cost less than the more basic options, like Plans A and B. It depends on where you live and the company selling the plan.
When you’re shopping for a Medigap plan, look for the coverage you’ll actually need. Medigap helps offset your out-of-pocket costs under Original Medicare, but there’s a monthly premium for these plans. It won’t help you to pay for coverage you won’t use. Instead, make a list of your likely costs and find the Medicare supplement plan that covers them.
Medigap plans can be very helpful as long as you choose a plan that both fits your budget and covers what you need it to.
Medicare Advantage Plans and Medigap
Medicare Advantage is the private portion of Medicare. Regulated by the federal government but sold by individual companies on the private market, Advantage plans combine the benefits of Parts A and B with additional benefits that vary by plan.
By law, these plans have to cover at least the same benefits as Original Medicare. Beyond that, they can offer other benefits. That could include prescription drugs, hearing aids, dental and vision benefits, gym memberships, post-hospital meal delivery and more.
If you need broader coverage, Medicare Advantage offers a good alternative to traditional Medicare. But if you do choose Advantage over Original, know that you can’t enroll in Medigap. People with Medicare Advantage cannot get a Medicare supplement plan. Medigap is only for people with Original Medicare.
That said, Advantage may limit your out-of-pocket costs in other ways. For example, Medicare Advantage plans are required to cap out-of-pocket expenses for the year, something that Original Medicare doesn’t do. You may also have lower copays with an Advantage plan, and you may not even have a premium, other than your required Part B premium.
Original Medicare with a Medigap plan may work well for you, or you might benefit from the added coverage of Medicare Advantage. When you’re choosing how to get your Medicare benefits, consider all the pros and cons, as well as the costs, to find the right coverage for your needs and budget.