There is no single "best" plan — the right one depends on your health, budget, and how much out-of-pocket risk you want to carry

Medicare Supplement plans (also called Medigap) all cover the same gaps in Original Medicare — copayments, coinsurance, and deductibles. The difference is how much they cover and what you pay in premiums each month. Plan G covers the most; Plan N covers less but costs less per month. Plan F is no longer sold to people new to Medicare. Your "best" plan is the one whose monthly cost plus expected out-of-pocket expenses adds up to less than you can afford to spend, while still protecting you if you get seriously ill.

The catch is that you cannot predict your health a year from now. What matters most is understanding what each plan actually covers, what it costs in your state and at your age, and whether you can switch plans later if your needs change.

Key Takeaways

  • Plan G covers nearly all of Medicare's gaps and is the most popular choice for people enrolling in Medigap now, though it has a higher monthly premium.
  • Plan N costs less per month but leaves you responsible for some copayments and a higher deductible, so it works best if you rarely see doctors.
  • You can switch plans during the annual open enrollment period (October 15 to December 7) or if you have a may have access to life event, though some insurers may deny you based on health.
  • Premiums vary by state, age, and insurance company — getting quotes from at least three insurers in your area is the only way to know what you will actually pay.
  • Enrollment rules are strictest during your first eight months after turning 65 or enrolling in Medicare Part B; outside that window, insurers can refuse you or charge more.

What Each Plan Covers and What You Pay Out of Pocket

Medicare Supplement plans are standardized by the federal government, which means Plan G from one insurance company covers exactly the same things as Plan G from another. The only differences are the monthly premium and customer service. The most common plans are G, N, and K.

Plan G covers your Part B deductible (the amount you pay before Medicare starts paying), all copayments and coinsurance for hospital and doctor visits, and excess charges if a doctor does not accept Medicare's approved amount. You pay only the monthly premium; there are no other out-of-pocket costs for covered services. Plan G premiums range widely by state and age — a 65-year-old in one state might pay $120 per month, while the same person in another state pays $180. You will need to get quotes to know your actual cost.

Plan N covers most of the same things as Plan G but leaves you responsible for a $50 to $200 copayment for some doctor visits and a $20 copayment for emergency room visits (waived if admitted). You also pay the Part B deductible yourself. The monthly premium is usually $30 to $50 less than Plan G, but you could spend $500 to $1,000 more per year in copayments if you see doctors frequently. Plan N makes sense if you are healthy and rarely need care.

Plan K covers less and costs even less per month, but it leaves you responsible for a percentage of costs up to an annual out-of-pocket limit (around $6,700 in 2024, though this changes yearly). Plan K is rarely chosen because the savings on premiums usually do not offset the risk of high out-of-pocket costs.

How Premiums Are Set and Why They Vary So Much

Insurance companies use three methods to set Medigap premiums: age-based (your premium rises as you age), issue-age (your premium is locked to your age when you enroll and rises slowly), or community-rated (everyone in your state pays the same regardless of age). Most insurers use age-based pricing, which means your premium will increase every year, sometimes by 5 to 10 percent annually.

The same plan from different insurers in the same state can cost $50 to $100 per month apart. A 65-year-old in Florida might find Plan G for $130 from one company and $210 from another. This is why getting quotes from at least three insurers is essential — you could save $1,000 per year by choosing the cheaper option. Most insurers let you get a quote online or by phone without any commitment.

Your state also matters. Some states regulate Medigap premiums more strictly than others, which affects how much variation you see. Moving to a different state can change your premium significantly, even for the same plan.

When You Can Enroll and What Happens If You Miss the Window

The best time to enroll in a Medigap plan is during your Medigap Open Enrollment Period, which lasts six months starting the month you turn 65 and enroll in Medicare Part B. During this window, insurers cannot deny you coverage or charge you more based on your health — this is called may provide issue. If you have a pre-existing condition, diabetes, or cancer, it does not matter; you pay the same premium as anyone else your age.

If you miss this window, you can still enroll during the annual open enrollment period (October 15 to December 7 each year), but insurers can refuse you or charge you more if you have health problems. Some states have additional protections that extend may provide issue beyond six months, but not all. You should check your state's rules if you are past your initial window.

You can also switch from one Medigap plan to another during open enrollment, though again, insurers can deny you if you are outside your initial six-month window. If you want to switch to a cheaper plan and your current insurer refuses you, you may be stuck with your current plan until the next open enrollment period.

Comparing Plans Side by Side: What to Look For

When you get quotes, you will see a chart showing what each plan covers. Focus on the out-of-pocket costs that matter most to you. If you see a specialist regularly, the copayment difference between Plan G and Plan N ($0 versus $50 per visit) could add up to hundreds of dollars per year. If you rarely see doctors, Plan N's lower premium might save you money overall.

Also check whether the insurer has a good reputation for paying claims quickly and handling customer service. You can read reviews on the National Association of Insurance Commissioners (NAIC) website or ask your doctor's office which insurers they work with most smoothly. Some insurers are known for slow claim processing, which can affect your out-of-pocket experience even if the plan itself is good.

Do not assume the cheapest plan is the best deal. A plan that costs $20 less per month but leaves you with higher copayments might cost you more overall if you need care. Use a straightforward spreadsheet: add the monthly premium times 12, then add your expected out-of-pocket costs based on how often you see doctors and what those visits usually cost. The plan with the lowest total is usually the right choice.

What Happens If You Switch Plans or Move States

You can switch Medigap plans during the annual open enrollment period without penalty. If you move to a different state, you may be able to switch plans when ready because moving is considered a may have access to life event. However, some insurers do not operate in all states, so your current plan might not be available in your new location. You will need to find a new plan in your new state, and the insurer can deny you if you are outside your initial six-month window.

If you switch from Original Medicare to a Medicare Advantage plan (Part C) and then want to go back to Original Medicare and Medigap, you may lose your may provide issue rights. This is a major decision that should not be made lightly. Before switching away from Medigap, understand that getting back into a Medigap plan later could be difficult or expensive.

How to Get Quotes and Enroll

You can get quotes directly from insurance companies' websites or by calling their customer service lines. Most insurers have online quote tools where you enter your age, state, and the plan you are interested in, and you get a premium estimate in seconds. Write down the quotes from at least three companies so you can compare.

You can also work with a licensed insurance broker who represents multiple insurers. Brokers do not charge you — they are paid by the insurance company — and they can help you understand the differences between plans. To find a broker, search "Medicare insurance broker" plus your state name, or ask your doctor's office for a referral.

Once you have chosen a plan and insurer, you can enroll online, by phone, or by mail. Enrollment usually takes a few minutes online. Your coverage typically starts the first day of the month after the insurer receives your process, though this varies by company.

Frequently Asked Questions

Can I switch Medigap plans if my premium goes up too much?

Yes, during the annual open enrollment period (October 15 to December 7), you can switch to a different plan or a different insurer. However, if you are outside your initial six-month enrollment window, the new insurer can deny you or charge you more based on your health. If you are within your six-month window, you have may provide issue rights and can switch without penalty.

What is the difference between Medigap and Medicare Advantage?

Medigap (Medicare Supplement) works alongside Original Medicare and covers gaps in what Medicare pays. Medicare Advantage (Part C) replaces Original Medicare entirely and usually has lower premiums but higher out-of-pocket costs and network restrictions. You cannot have both at the same time. Medigap gives you more freedom to see any doctor; Medicare Advantage is cheaper if you use in-network providers.

Do I have to enroll in Medigap when I turn 65?

No, but if you do not enroll during your six-month window and later decide you want coverage, insurers can refuse you or charge you more. If you are healthy and rarely see doctors, you might skip Medigap and enroll later, but you risk being denied or paying a higher premium. Most people enroll right away to lock in may provide issue rights.

Will my Medigap premium ever go down?

Premiums almost never go down; they typically rise each year. However, you can switch to a cheaper plan or insurer during open enrollment. Some people switch every year to find the lowest premium available, though this means dealing with a new insurer each time. Others stay with the same plan for stability and accept the annual increase.

What if I cannot afford any Medigap plan?

If you have limited income, you may be able to get help paying for Medigap premiums through your state's Medicare Savings Program. This program pays some or all of your Part B premium, deductible, and coinsurance. Contact your state Medicaid office or call 1-800-MEDICARE to learn whether you may have access to and how the process works.