Medicare Supplement Insurance is private insurance designed to help pay some of the healthcare costs that Original Medicare does not fully cover. Also known as Medigap, these policies work alongside Original Medicare Part A and Part B rather than replacing them.
Understanding Medicare Supplement Insurance can help you better understand how Original Medicare works, what costs you may still have, and what supplemental coverage options may be available to you.
If you’re exploring Medicare coverage, it is important to look at the details of each option carefully because benefits, premiums, eligibility and availability can vary.
Medicare Supplement Insurance: What Is It?
Medicare Supplement Insurance is additional insurance that helps pay certain out-of-pocket costs associated with Original Medicare.
Original Medicare generally pays its share of covered healthcare services and supplies, while you are responsible for your share of the costs. A Medigap policy may help pay some of those remaining costs, such as certain copayments, coinsurance and deductibles, depending on the policy you choose.
Generally, you must have Medicare Part A and Part B to buy a Medigap policy. A Medigap policy is separate from Medicare itself and is sold by private insurance companies.
1. Medicare Supplement Insurance Works With Original Medicare
One of the most important things to understand about Medicare Supplement Insurance is that it works with Original Medicare.
Original Medicare includes Part A and Part B. Medigap is designed to supplement that coverage by helping with certain costs that remain after Medicare pays its share.
For example, depending on the Medigap policy, the policy may help with certain Medicare-covered copayments, coinsurance or deductibles. The specific benefits depend on the plan type.
If you are considering Original Medicare and additional coverage, you can also explore our Medicare Options page.
2. Medicare Supplement Insurance Is Different From Medicare Advantage
Medicare Supplement Insurance and Medicare Advantage are not the same type of coverage.
Medicare Advantage, also called Part C, is an alternative way to receive Medicare benefits through a Medicare-approved private health plan.
Medigap, on the other hand, supplements Original Medicare. Medicare.gov explains that you generally cannot have a Medigap policy while enrolled in a Medicare Advantage Plan.
This distinction is important when comparing your Medicare choices.
If you’re considering Medicare Advantage, you can learn more about Medicare Advantage plans through Caring Curations.
3. Medigap Plans Are Standardized
Another important feature of Medicare Supplement Insurance is standardization.
In most states, Medigap policies are identified by letters such as Plan A, Plan B, Plan C, Plan D, Plan F, Plan G, Plan K, Plan L, Plan M and Plan N. The benefits of plans with the same letter are standardized, although premiums and the insurance company selling the policy can differ.
Not every Medigap plan is available in every state, and some plans have eligibility restrictions based on when you became eligible for Medicare. For example, people who became eligible for Medicare on or after January 1, 2020 generally cannot buy Plans C or F.
Because plan availability and rules can vary, reviewing the options available in your location is important.
4. Medicare Supplement Insurance Can Help With Certain Out-of-Pocket Costs
Original Medicare does not pay every healthcare cost in full.
Medicare Supplement Insurance may help cover certain remaining costs for Medicare-covered services, depending on the plan.
These costs can include:
- Certain Part A coinsurance
- Certain Part B coinsurance or copayments
- Some deductibles
- Certain other Medicare-covered cost-sharing amounts
The exact benefits depend on the Medigap plan. Medicare.gov provides a comparison of standardized Medigap plan benefits so consumers can review what each plan may cover.
It is important to remember that Medigap does not cover everything. Generally, Medigap policies do not cover routine dental care, vision care, hearing aids, long-term care or prescription drugs. A separate Medicare Part D plan may be needed for prescription drug coverage.
You can also learn about Medicare Part D prescription drug coverage on our website.
5. When You Buy Medicare Supplement Insurance Matters
Timing can be important when purchasing Medicare Supplement Insurance.
Your Medigap Open Enrollment Period is a one-time six-month period that generally begins when you are 65 or older and enrolled in Medicare Part B. During this period, you generally have more protections when buying a Medigap policy, including protections related to medical underwriting and pre-existing health conditions.
After this period, you may have fewer choices or potentially pay more, depending on your circumstances and applicable rules.
There are also specific situations that may give you guaranteed-issue rights or other opportunities to purchase Medigap coverage. Because these situations can be fact-specific, it is important to review your circumstances carefully.
6. Medicare Supplement Insurance Has a Monthly Premium
Medicare Supplement Insurance is private insurance, so you generally pay a monthly premium to the insurance company for your policy.
You also continue paying your Medicare Part B premium while you have Medigap coverage. Medigap premium amounts can vary depending on factors such as the policy, insurance company and location. Premiums may also change over time.
When comparing policies with the same letter, it is useful to compare premiums and the company’s terms because the basic standardized benefits are generally the same for that lettered plan.
Medicare.gov recommends comparing policies and prices when shopping for Medigap coverage.
7. Medicare Supplement Insurance Does Not Include Prescription Drug Coverage
Another important fact about Medicare Supplement Insurance is that Medigap policies sold after 2005 generally do not include prescription drug coverage.
If you want Medicare prescription drug coverage, you may need to enroll in a separate Medicare Part D prescription drug plan.
This is an important distinction to consider when reviewing your overall Medicare coverage.
Your healthcare needs, medications, preferred providers and budget can all be relevant when evaluating your coverage options.
Medicare Supplement Insurance: What Should You Compare?
When researching Medicare Supplement Insurance, don’t look only at the monthly premium.
Consider:
- Which Medigap plans are available in your area
- The benefits included with each plan
- The monthly premium
- How premiums may change
- Whether the insurance company is licensed to sell Medigap in your state
- Your Medicare Part A and Part B coverage
- Your prescription drug coverage
- Your healthcare needs
- Any applicable enrollment or guaranteed-issue rights
Medicare.gov recommends comparing policies from insurance companies licensed to sell Medigap in your state. Not every plan is offered in every state, and not every insurance company sells every plan.
Medicare Supplement Insurance Plans Compared
Because Medigap plans are standardized in most states, the letter tells you what the plan covers. The price is what differs between insurance companies. Here is a simplified look at the most common Medicare Supplement Insurance plans in 2026. (Medicare.gov)
| Plan | What it covers | What you still pay |
|---|---|---|
| Plan A | Part A coinsurance and extra hospital days, Part B coinsurance, blood, hospice coinsurance | Part A and Part B deductibles, skilled nursing coinsurance, excess charges |
| Plan G | Nearly all Medicare cost-sharing, including the Part A deductible, skilled nursing coinsurance, Part B excess charges and 80% of foreign travel emergencies | The Part B deductible ($283 in 2026) |
| Plan N | Similar to Plan G, except Part B excess charges | The Part B deductible, plus copays of up to $20 for some office visits and up to $50 for some ER visits |
| Plan K | 50% of most cost-sharing | The rest, up to an out-of-pocket limit of $8,000 in 2026 |
| Plan L | 75% of most cost-sharing | The rest, up to an out-of-pocket limit of $4,000 in 2026 |
| High-deductible Plan G | The same benefits as Plan G after a deductible | Up to $2,950 in 2026 before the policy starts paying |
Plans C and F, which also cover the Part B deductible, can only be bought by people who were eligible for Medicare before January 1, 2020. If you are new to Medicare now, Plan G is usually the most comprehensive option available.
How Medicare Supplement Insurance Is Priced
Two companies can charge very different premiums for the exact same plan letter. One reason is the way each insurer prices its policies:
- Community-rated: generally everyone pays the same premium regardless of age.
- Issue-age-rated: the premium is based on your age when you buy the policy, so buying earlier can mean lower premiums.
- Attained-age-rated: the premium is based on your current age and goes up as you get older.
All three types can also rise because of inflation and claims costs. When you compare Medicare Supplement Insurance quotes, ask how each company prices its policies and how its rates have changed over the past few years.
What Else Affects Your Medicare Supplement Insurance Premium?
Beyond the pricing method, several other factors shape what you pay for Medicare Supplement Insurance:
- Where you live: premiums vary by state and often by ZIP code.
- The plan letter: plans with more coverage, such as Plan G, usually cost more than plans with more cost-sharing, such as Plan N or Plan K.
- Household discounts: some insurers offer a discount when two people in the same household buy policies.
- Tobacco use: in many states, insurers can charge tobacco users more.
- When you apply: outside protected enrollment windows, your health may affect whether you are accepted and what you pay in most states.
Because so many factors are involved, the only way to know your real Medicare Supplement Insurance cost is to compare quotes for the same plan letter from several companies. That is something we do for our clients at no charge.
Medicare Supplement Insurance in New York
Caring Curations is based in Staten Island, and New York has some of the strongest Medigap protections in the country. Under New York rules:
- You can apply for a Medicare Supplement Insurance policy at any time of the year, not just during your 6-month Medigap Open Enrollment Period.
- Policies are community-rated, so insurers can’t charge you more because of your age or health. Prices can still vary by insurer and by where you live.
- These protections also apply to people under 65 who have Medicare because of a disability.
In some cases a waiting period for pre-existing conditions may apply if you didn’t have prior coverage, so review the details before you switch. (healthinsurance.org) If you live in another state, the federal rules and your own state’s rules apply, and they are often less flexible.
Medicare Supplement Insurance if You Are Under 65
People under 65 can get Medicare because of a disability, end-stage renal disease or ALS. Federal law doesn’t require insurers to sell Medicare Supplement Insurance to people under 65, but many states do, and the rules vary widely.
Some states require insurers to offer at least one Medigap plan to people under 65, while others offer broader access. Premiums for under-65 enrollees can also be higher than for people who are 65. In New York, the same year-round, community-rated rules apply whether you are under or over 65, which is a major advantage for disabled New Yorkers.
If you are under 65 and can’t find affordable Medicare Supplement Insurance, you will get a new Medigap Open Enrollment Period when you turn 65. At that point you can buy any Medigap policy sold in your state without health questions.
Because state rules change from time to time, it is a good idea to confirm the current under-65 rules with your state insurance department or a licensed advisor before you apply.
Guaranteed Issue Rights: When Insurers Must Sell You a Policy
Outside your Medigap Open Enrollment Period, federal law still gives you guaranteed issue rights in certain situations. In these cases an insurer must sell you certain Medigap plans, can’t charge more because of your health, and can’t exclude pre-existing conditions. Common examples include:
- Your Medicare Advantage plan leaves your area or stops offering coverage
- You move out of your Medicare Advantage plan’s service area
- Your employer or union coverage that works with Medicare is ending
- You joined Medicare Advantage when first eligible at 65 and want to switch back to Original Medicare within the first 12 months
- Your Medigap insurer goes bankrupt or misled you
These rights generally have time limits, often 63 days after your other coverage ends, so keep any notices you receive. (Medicare.gov)
What Medicare Supplement Insurance Does Not Cover
Medicare Supplement Insurance fills gaps in Original Medicare, but it doesn’t add new types of benefits. In general, Medigap policies don’t cover:
- Prescription drugs (you need a separate Part D plan)
- Routine dental care, dentures and cleanings
- Routine eye exams, eyeglasses and contact lenses
- Hearing aids and routine hearing exams
- Long-term custodial care in a nursing home or at home
- Private-duty nursing
Many people with Medicare Supplement Insurance add a separate dental, vision and hearing plan to fill these gaps. Long-term care usually requires a separate long-term care policy or other planning.
How to Choose a Medicare Supplement Insurance Plan
A simple way to approach the decision:
- Decide on Original Medicare. Medigap only works with Original Medicare, not with Medicare Advantage.
- Pick a plan letter. Decide how much cost-sharing you are comfortable with. Plan G and Plan N are the most popular choices for people new to Medicare.
- Compare companies for that letter. Look at premiums, pricing method and rate history.
- Add drug coverage. Medigap doesn’t include prescription drugs, so pair it with a Medicare Part D plan.
- Check your timing. Apply during your Medigap Open Enrollment Period or another protected window when possible.
Medicare Supplement Insurance usually means a higher monthly premium but very predictable costs and the freedom to see any provider that accepts Medicare. To see how it compares with the alternative, read Medicare Advantage vs Original Medicare.
Frequently Asked Questions About Medicare Supplement Insurance
Is Medicare Supplement Insurance the same as Medigap?
Yes. Medigap is the common name for Medicare Supplement Insurance. Read our full explainer, What Is Medigap?
Which Medicare Supplement Insurance plan is most popular?
For people new to Medicare, Plan G is one of the most popular because it covers almost all Medicare cost-sharing except the Part B deductible. Plan N is a common lower-premium alternative.
Can I change my Medicare Supplement Insurance plan later?
Yes, but in most states insurers may review your health history if you switch outside a protected window. In New York, you can apply year-round.
Does Medicare Supplement Insurance cover prescription drugs?
No. Policies sold today don’t include drug coverage, so most people also enroll in a stand-alone Part D plan.
Can I use Medicare Supplement Insurance with any doctor?
Generally yes. If a doctor or hospital accepts Medicare, your Medigap policy generally works there too, anywhere in the U.S.
Related guides: Plan G vs Plan N, Medicare Part A and Medicare Part B.
Medicare Supplement Insurance: Get Help Understanding Your Options
Choosing Medicare Supplement Insurance involves understanding how Medigap works with Original Medicare and how different policies compare.
At Caring Curations Medicare and Health Advisors, we provide personalized guidance to help you understand the Medicare coverage options we are able to offer. We can explain differences between available options and help you identify questions to consider based on your circumstances.
You can Contact Caring Curations to learn more about your Medicare coverage options.
For official Medicare information, you can also review the Medicare.gov Medigap information
