Medicare Supplement Insurance
Also known as Medigap, is extra health insurance that you can buy from a private insurance company to help pay your share of out-of-pocket costs in Original Medicare (Part A and Part B), such as:
Deductibles: The amount you pay before Medicare starts to pay its share.
Coinsurance: Your share of the costs for covered healthcare services (usually a percentage).
Copayments: Fixed amounts you pay for covered healthcare services.
How Medigap Works:
You must have Original Medicare (Part A and Part B) to buy a Medigap policy.
You pay a monthly premium to the private insurance company for your Medigap policy, in addition to your Part B premium.
When you get healthcare services, Medicare pays its share, and then your Medigap policy helps pay your remaining costs.
Medigap policies are standardized by federal and state laws, and are identified by letters (Plans A, B, C, D, F, G, K, L, M, and N in most states).
Each lettered plan offers a specific set of benefits, so the coverage is the same regardless of which insurance company you buy it from. The main difference between policies with the same letter sold by different companies is the premium and potentially extra perks.
Generally, Medigap policies don't cover long-term care, vision or dental care, hearing aids, eyeglasses, or private-duty nursing. They also don't include prescription drug coverage; for that, you would need to enroll in a separate Medicare Part D plan.
Available Medigap Plans (as of 2025):
Plans A, B, C*, D, F*, G, K, L, M, and N.
Note: Plans C and F are only available to those who were eligible for Medicare before January 1, 2020.
Each plan offers a different level of coverage for Medicare Part A and Part B cost-sharing.
Plan G is often considered the most comprehensive plan available to new Medicare beneficiaries, as it covers almost all out-of-pocket costs.
Plan N offers lower premiums but has copays for some office visits and emergency room visits.
Plans K and L have cost-sharing features where you pay a percentage of certain services until you reach an out-of-pocket limit.
You can compare the benefits of each plan on the official Medicare website or through insurance company materials.
Costs of Medigap Policies:
Premiums: You pay a monthly premium to the insurance company. Premiums vary widely based on the plan you choose, the insurance company, your age, your location, and how the company prices its policies (community-rated, issue-age-rated, or attained-age-rated).
Community-rated: Everyone pays the same premium, regardless of age.
Issue-age-rated: Premiums are based on your age when you first buy the policy and don't increase due to age.
Attained-age-rated: Premiums are based on your current age and increase as you get older.
Deductibles: Some Medigap plans cover the Medicare Part A deductible, and some plans (like high-deductible Plan G) have their own deductible.
Copays/Coinsurance: Plan N has copays for certain services. Plans K and L have coinsurance where you pay a percentage of the costs.
When to Buy a Medigap Policy:
The best time to buy a Medigap policy is during your Medigap Open Enrollment Period. This is a 6-month period that starts the first month you have Medicare Part B (Medical Insurance) and you are age 65 or older. During this time, you have a guaranteed right to buy any Medigap policy sold in your state.
Outside your Open Enrollment Period, your ability to buy a Medigap policy and the price you pay may depend on underwriting, meaning the insurance company can deny coverage or charge you a higher premium based on your health.
Certain special enrollment periods may allow you to buy a Medigap policy outside your open enrollment, such as if you lose coverage from a Medicare Advantage plan.
Important Considerations:
You cannot have a Medigap policy and a Medicare Advantage Plan at the same time.
Medigap policies cover only one person. Spouses need separate policies.
It's important to shop around and compare Medigap policies from different insurance companies, as premiums for the same plan letter can vary significantly.
For the most up-to-date and personalized information, it's recommended to:
Visit the official Medicare website: https://www.medicare.gov/medigap-supplemental-insurance-plans/
Call 1-800-MEDICARE (1-800-633-4227).
Contact your State Insurance Department for information specific to your state.
