What's the Best Medigap Plan? A Clear Guide for Beneficiaries

If you've spent any time researching Medicare Supplement insurance — commonly called Medigap — you've probably noticed that the question 'which plan is best?' doesn't have a single clean answer. What it does have is a framework that can help you make a genuinely smart decision based on your own health history, financial situation, and tolerance for unpredictable medical bills. The standardized nature of Medigap plans is actually your biggest advantage here: every Plan G sold in your state must cover the exact same benefits, whether you buy it from AARP/UnitedHealthcare, Mutual of Omaha, or a regional insurer. That means you're shopping on price and company reputation — not on hidden benefit differences.

For most people newly enrolling in Medicare in 2025, the conversation about Medigap comes down to three plans: Plan G, Plan N, and — for those who qualify — Plan F. Plan F was the gold standard for decades because it covered absolutely everything, including the Medicare Part B deductible. But Congress eliminated Plan F (and Plan C) for anyone who became eligible for Medicare on or after January 1, 2020. If you turned 65 before that date and already have Plan F, you can keep it. If you're newly eligible, Plan F is simply off the table for you.

That makes Plan G the new comprehensive benchmark. In 2025, Plan G covers 100% of Medicare Part A hospital costs and coinsurance, Part A hospice care coinsurance, skilled nursing facility coinsurance, Part B coinsurance and copayments, the first three pints of blood, and foreign travel emergency care (up to plan limits). The only thing it doesn't cover is the Medicare Part B deductible, which is $257 in 2025. You pay that once per year, and after that, Plan G essentially eliminates your Medicare cost-sharing for the rest of the year. For someone who sees multiple specialists, undergoes surgery, or manages a chronic condition like heart disease or diabetes, that predictability is enormously valuable. Monthly premiums for Plan G vary widely by age, location, and insurer — you might see quotes ranging from roughly $100 to $300 or more per month depending on where you live and how old you are.

Plan N is the other serious contender, and it's worth understanding exactly how it differs from Plan G before dismissing it as inferior. Plan N covers the same broad categories as Plan G, but it introduces cost-sharing at the point of service: up to a $20 copay for office visits and up to a $50 copay for emergency room visits (waived if you're admitted). Critically, Plan N does not cover Part B excess charges — the additional amount (up to 15% above Medicare's approved rate) that doctors who don't accept Medicare assignment can legally charge you. In states where most physicians accept Medicare assignment, excess charges are rare and Plan N works well. In states like Massachusetts, Ohio, or parts of the South where non-participating physicians are more common, excess charges can add up. Before choosing Plan N, check your doctors' assignment status at Medicare.gov's physician finder tool. If all your providers accept Medicare assignment and you're generally healthy with infrequent office visits, Plan N's lower premium — often $30 to $80 less per month than Plan G — can make it the smarter financial choice over time.

High-deductible Plan G is a third option that deserves mention, particularly for beneficiaries who are in good health and want the lowest possible monthly premium while still having catastrophic protection. With high-deductible Plan G in 2025, you pay all Medicare-covered costs out of pocket until you reach a $2,870 deductible, after which the plan covers everything Plan G normally covers. Monthly premiums for high-deductible Plan G can be as low as $30 to $60 in many markets. This structure functions somewhat like a health savings account strategy — you're betting that your annual out-of-pocket costs will stay below the deductible, and you pocket the premium savings in years when they do. It's not appropriate for someone managing multiple serious conditions, but for a 65-year-old in good health who wants a safety net against catastrophic costs, it's a legitimate and often overlooked option.

Timing your Medigap purchase is just as important as choosing the right plan letter. Your federal Open Enrollment Period for Medigap runs for six months starting the first month you are both 65 or older and enrolled in Medicare Part B. During this window, insurers operating in your state must sell you any Medigap plan they offer at standard rates — they cannot reject you, charge you more, or impose waiting periods based on pre-existing conditions. Once this window closes, you lose those guaranteed issue rights in most states, and insurers can use medical underwriting to deny coverage or charge significantly higher premiums. Missing this window is one of the most costly mistakes Medicare beneficiaries make, and it's largely irreversible unless you qualify for a Special Enrollment Period triggered by events like losing employer coverage or your current plan being discontinued.

A handful of states have enacted additional consumer protections worth knowing about. New York and Connecticut require guaranteed issue rights for Medigap year-round, meaning insurers must sell you a plan regardless of your health at any time. California, Oregon, Nevada, Illinois, Idaho, Kentucky, Louisiana, Maine, Maryland, Missouri, New Jersey, Oklahoma, and several others have enacted a 'birthday rule' that gives you a 30-day window each year around your birthday to switch to a Medigap plan with equal or lesser benefits without medical underwriting. If you live in one of these states and feel trapped in a plan that no longer fits your needs, your birthday window may be your opportunity to make a change. Contact your state's Department of Insurance to confirm the exact rules and timing in your state, as the specifics vary.

Premium pricing structures also matter more than most people realize when comparing Medigap plans. Insurers use three different methods to set premiums. Community-rated plans charge everyone the same premium regardless of age — these often look expensive at 65 but become relatively affordable as you age. Issue-age-rated plans set your premium based on your age when you first buy the policy and don't automatically increase as you get older, though they may still rise with inflation. Attained-age-rated plans — the most common type — start with the lowest premiums at 65 but increase as you age, sometimes substantially. A plan that costs $120 per month at 65 under an attained-age structure might cost $200 or more by age 75. When comparing quotes, always ask which rating method the insurer uses, and factor in long-term cost trajectory, not just the initial premium.

Finally, don't overlook the financial stability and customer service reputation of the insurer itself. Because Medigap benefits are standardized, the company behind the plan matters for things like claims processing speed, premium increase history, and whether they're likely to remain in your market long-term. AM Best financial strength ratings (look for A or better) and state complaint ratios — available through your state insurance commissioner's website — are two practical tools for vetting insurers before you commit. Your State Health Insurance Assistance Program (SHIP) offers free, unbiased counseling to help you compare plans in your area; find your local SHIP counselor at shiphelp.org. These counselors have no financial stake in your decision and can pull actual premium quotes from all insurers operating in your county.