Medicare supplement premiums vary by plan type, your age, where you live, and which insurance company you choose — there is no single "best" plan because the right one depends on what coverage gaps matter most to you.
A Medigap plan (the formal name for Medicare supplement insurance) costs anywhere from roughly $100 to $400 per month for someone in their mid-60s, but that range widens as you age. The same plan can cost 30 to 50 percent more at age 75 than it did at 65. Some states allow insurers to charge based on your age; others cap how much they can raise your premium each year. Your location matters as much as your age — the same Plan G might cost $150 monthly in one county and $280 in another.
The trade-off is straightforward: plans that cover more of Medicare's gaps cost more each month but leave you with lower out-of-pocket costs when you actually need care. Plans that cover less cost less upfront but expose you to higher deductibles and copayments. The "best" plan is the one whose monthly cost plus your expected medical expenses adds up to less than the alternatives.
Key Takeaways
- Plan G and Plan N are the most common choices for people newly may be able to access for Medicare, with Plan G typically costing $20 to $60 more per month but covering the Part B deductible that Plan N does not.
- Your age when you first buy a supplement plan matters permanently — if you enroll within six months of turning 65, insurers cannot charge you more based on your health history, a protection called may provide issue.
- The same plan costs different amounts from different insurers in your state, so comparing quotes from at least three companies can save you $50 to $150 per month.
- Premiums rise every year, and the increase varies by insurer and plan — some companies raise rates 3 to 5 percent annually, while others jump 8 to 12 percent.
- Ten standardized plan types exist (A, B, C, D, G, K, L, M, N, and high-deductible G), and the benefits within each type are identical across all insurers, so you are only comparing price and customer service.
How Plan Type Affects Your Monthly Cost
The ten standardized Medigap plans offer different levels of coverage, and each level has a corresponding price range. Plan A is the most basic and typically costs $100 to $180 per month. It covers Medicare Part A coinsurance and copayments, Part B copayments, and the first three pints of blood, but it does not cover the Part B deductible or excess charges.
Plan G is the most comprehensive standard option and usually costs $200 to $350 per month depending on your age and location. It covers nearly everything Plan A does, plus the Part B deductible, excess charges, and foreign travel emergency care. The difference in monthly cost between Plan A and Plan G is typically $80 to $150, but Plan G saves most people money over time because it eliminates the Part B deductible ($240 in 2024) and protects against excess charges if your doctor does not accept Medicare's approved amount.
Plan N sits in the middle and costs roughly $150 to $280 per month. It covers most of what Plan G does except the Part B deductible, and it charges a copayment for some doctor visits and emergency room trips. For people who see their doctor infrequently, Plan N's lower premium can outweigh the small copayments.
High-deductible Plan G costs $50 to $100 per month but requires you to pay a deductible (usually $2,700 to $3,000 annually) before the plan covers anything. This option makes sense only if you are healthy, do not expect major medical expenses, and want to minimize your monthly insurance cost.
How Your Age and Enrollment Timing Affect Price
Your age when you enroll in a Medigap plan locks in a pricing structure that follows you for as long as you own the plan. If you buy Plan G at age 65, your premiums will rise each year, but you will never pay the age-65 rate for someone who enrolls at 72. This is why enrolling as soon as you turn 65 and become may be able to access for Medicare Part B is financially important — you get the lowest starting rate available.
More importantly, if you enroll within six months of turning 65, federal law requires insurers to offer you may provide issue protection. This means they cannot charge you more or deny you coverage based on your health history, pre-existing conditions, or medical claims. If you wait beyond that six-month window, insurers can underwrite your process and charge you a higher premium or refuse to sell you a plan altogether. This protection applies only during that initial enrollment window, so missing it can cost you thousands over time.
After your initial enrollment period, most states allow insurers to use age-based rating, meaning your premium increases as you age. Some states also allow issue-age rating, where your premium is based on your age when you first bought the plan and then rises annually. A few states use community rating, where everyone in the same plan pays the same premium regardless of age. Your state's rating method affects how much your costs will climb over time.
How Location and Insurance Company Affect What You Pay
The same Plan G can cost $180 per month from one insurer and $260 from another in the same state. This variation exists because each company sets its own rates based on its claims experience, administrative costs, and business strategy. Shopping across multiple insurers is the single most effective way to lower your premium.
Geographic variation is also significant. Urban areas typically have more insurers competing for business, which can drive prices down. Rural areas often have fewer options and higher costs. Some insurers operate statewide; others focus on specific regions. Your ZIP code determines which companies will even sell you a plan, so you cannot straightforward choose the cheapest option nationally — you can only choose among the insurers licensed to sell in your area.
To find what plans cost in your location, you can enter your information on Medicare.gov's plan finder tool, which shows available plans and their premiums from all insurers in your area. You can also contact insurers directly or work with a licensed insurance agent who represents multiple companies. Agents do not charge you a fee — they are paid by the insurance company — so there is no cost to getting help comparing options.
Annual Premium Increases and How They Compound
Every Medigap insurer raises its premiums annually, but the size of the increase varies widely. Some companies increase rates 3 to 5 percent per year; others jump 8 to 12 percent or more. Over ten years, a 5 percent annual increase compounds to roughly 63 percent total, while a 10 percent annual increase compounds to 159 percent. This means a plan costing $200 per month at age 65 could cost $326 at age 75 with 5 percent annual increases, or $526 with 10 percent annual increases.
You cannot predict future rate increases, but you can look at an insurer's historical rate increases if that information is available through your state insurance commissioner's office. Some states publish this data; others do not. You can also ask an insurance agent or the company directly what their recent rate history has been, though they are not required to disclose it.
If your premiums become unaffordable, you have the right to switch to a different Medigap plan or a different insurer, though switching after your initial enrollment period may involve medical underwriting. Some states have protections that allow you to switch to a lower-benefit plan without underwriting, but the rules vary by state.
Comparing Your Total Out-of-Pocket Cost, Not Just the Premium
The cheapest monthly premium is not always the cheapest plan overall. A plan that costs $50 less per month but leaves you with a $2,000 annual deductible and higher copayments may cost you more in total than a plan costing $50 more per month with no deductible and lower copayments — but only if you actually use medical services.
To compare plans fairly, estimate your expected medical costs for the year. If you are generally healthy and see your doctor once or twice annually, a lower-premium plan with small copayments might be your best choice. If you have chronic conditions, take multiple medications, or see specialists regularly, a higher-premium plan with broader coverage usually saves money. Medicare.gov's plan finder tool shows both the premium and the estimated out-of-pocket costs for each plan based on your prescription drugs and doctors, which can help you make this calculation.
When to Enroll and How to Lock in the Best Rate
Your best opportunity to enroll in a Medigap plan at the lowest rate with may provide issue protection is within six months of turning 65 and enrolling in Medicare Part B. This window is called your Medigap open enrollment period, and it is the only time federal law guarantees insurers will sell you any plan at any price without medical underwriting.
If you miss this window, you can still buy a Medigap plan, but insurers can refuse to sell to you or charge you more based on your health. Some states have additional protections that allow you to switch plans or enroll later without underwriting, but these vary by state. The safest approach is to enroll during your initial six-month window, even if you are still working and have employer coverage — you can always switch to employer coverage later if needed.
Once you enroll, your plan renews automatically each year unless you cancel it. You can switch to a different plan or insurer during the annual open enrollment period (October 15 to December 7), but switching after your initial enrollment period may involve medical underwriting depending on your state and the plan you are switching to.
Frequently Asked Questions
Is there a Medigap plan that costs less than $100 per month?
Plan A sometimes costs less than $100 per month for people in their mid-60s in lower-cost areas, but this is uncommon. High-deductible Plan G can cost $50 to $100 monthly, but you pay a large deductible before coverage begins. Most people find that plans costing $120 to $200 per month offer better value.
Do I have to buy a Medigap plan, or can I just use Medicare alone?
No, you do not have to buy a supplement plan. Medicare Part A and Part B leave you responsible for deductibles, copayments, and coinsurance. Some people choose to use Medicare alone and pay these costs out of pocket, while others buy a Medigap plan to reduce their financial risk. The choice depends on your health, your savings, and your comfort with uncertainty.
Can I switch Medigap plans if my premium gets too high?
Yes, you can switch to a different plan or insurer during the annual open enrollment period (October 15 to December 7) or if you have a may have access to life event. Switching after your initial enrollment period may involve medical underwriting, meaning the new insurer can charge you more or deny coverage based on your health. Some states have protections that allow switching to lower-benefit plans without underwriting.
What is the difference between Medigap and Medicare Advantage?
Medigap is supplemental insurance that works alongside Original Medicare (Parts A and B). Medicare Advantage is an alternative to Original Medicare offered by private insurers. Medigap typically costs more monthly but offers broader coverage and more flexibility in choosing doctors. Medicare Advantage often costs less monthly but limits you to a network of doctors and may require prior authorization for services.
Will my Medigap premium increase every year?
Yes, all Medigap insurers raise premiums annually. The increase varies by company and can range from 3 to 12 percent or more per year. You cannot avoid increases, but you can shop for a new insurer during open enrollment if your current company's rates become unaffordable compared to competitors.