What's the Best Medigap Plan for Medicare Beneficiaries?

If you're enrolled in Original Medicare and trying to figure out which Medigap plan makes the most financial sense, you're not alone. With 10 standardized plan types labeled A through N (minus E, H, I, and J, which are no longer sold), the choices can feel overwhelming. But in practice, most beneficiaries end up comparing just two or three serious contenders. Understanding what each plan actually covers — and what it costs in real dollars — is the fastest way to cut through the confusion.

Medigap, also called Medicare Supplement Insurance, is sold by private insurers to fill the gaps left by Original Medicare Parts A and B. Those gaps are significant. Without supplemental coverage, you're on the hook for the Part A hospital deductible of $1,676 per benefit period in 2025, 20% coinsurance on all Part B services with no annual cap, and daily coinsurance charges for extended hospital stays. A serious illness or surgery can easily generate tens of thousands of dollars in out-of-pocket exposure under Original Medicare alone. Medigap plans are designed to absorb most or all of that exposure, depending on which plan you choose.

Plan G has emerged as the gold standard for new Medicare enrollees since Plan F — the previous top-tier option — became unavailable to anyone who turned 65 after January 1, 2020. Plan G covers the Part A deductible, Part A coinsurance and hospital costs up to 365 days after Medicare benefits are exhausted, Part B coinsurance or copayments, the first three pints of blood, Part A hospice care coinsurance, skilled nursing facility coinsurance, and foreign travel emergency care (up to plan limits). The only gap Plan G leaves is the Part B deductible, which is $257 in 2025. You pay that once per year, and after that, Plan G covers your 20% share of every Medicare-approved outpatient service. For someone with regular specialist visits, infusions, imaging, or any chronic condition requiring ongoing care, that predictability has real financial value.

Plan N is the strongest alternative to Plan G for beneficiaries who are in reasonably good health and want to reduce their monthly premium. Plan N covers the same core benefits as Plan G — including the Part A deductible and skilled nursing facility coinsurance — but it introduces cost-sharing at the point of care. You'll pay up to $20 for office visits and up to $50 for emergency room visits that don't result in an inpatient admission. Plan N also does not cover Part B excess charges, which are the additional fees some doctors charge above Medicare's approved amount. If you live in a state where doctors commonly bill excess charges, or if you see specialists who don't accept Medicare assignment, Plan N's exposure can add up. But for a beneficiary who sees their primary care doctor a handful of times per year and rarely visits the ER, the premium savings from Plan N — which can range from $30 to $80 per month depending on your age, gender, and location — may more than offset those copays over the course of a year.

High-Deductible Plan G is worth serious consideration for beneficiaries who are healthy, have significant savings, and are comfortable taking on more financial risk in exchange for much lower premiums. In 2025, the deductible for HD Plan G is $2,870. Until you've paid that amount out of pocket in a given year, you're responsible for the same cost-sharing as someone with no Medigap coverage at all. But once you hit the deductible, Plan G's full benefits kick in for the rest of the year. Monthly premiums for HD Plan G can run $40 to $80 in many markets — a fraction of what standard Plan G costs, which often ranges from $120 to $200 or more depending on your age and zip code. For a 65-year-old in good health who rarely uses medical services, the math can favor HD Plan G significantly over a multi-year horizon. The risk is that a single bad year — a hospitalization, a cancer diagnosis, a major surgery — will cost you the full deductible before your coverage absorbs the rest.

Plan A and Plan B are the most basic Medigap options and are rarely the best choice for most beneficiaries. Plan A covers only the core benefits: Part A coinsurance and hospital costs, Part B coinsurance, blood, and hospice coinsurance. It does not cover the Part A deductible, skilled nursing facility coinsurance, or foreign travel emergencies. Plan B adds coverage for the Part A deductible but still leaves skilled nursing and foreign travel uncovered. Given that premiums for Plan A and Plan B are often not dramatically lower than Plan N in many markets, and that Plan N covers substantially more, most beneficiaries comparing entry-level options will find Plan N to be the better value.

Pricing is where things get complicated, because Medigap insurers use three different rating methods that affect how your premium changes over time. Community-rated plans charge everyone the same premium regardless of age — your premium may increase due to inflation and medical costs, but not because you're getting older. Issue-age-rated plans set your premium based on the age you are when you first enroll, and that premium also doesn't increase with age. Attained-age-rated plans start lower but increase as you get older, which can make them significantly more expensive by your late 70s and 80s. Most states allow all three rating methods, but New York and Connecticut require community rating, which tends to make Medigap more affordable for older enrollees in those states. When comparing plans, always ask the insurer which rating method they use — a lower premium today from an attained-age plan can become a much higher premium a decade from now.

Timing your enrollment matters enormously because of how Medigap's guaranteed issue rules work. During your six-month Medigap Open Enrollment Period — which begins the month you turn 65 and are enrolled in Part B — insurers cannot deny you coverage or charge you more based on your health history. Once that window closes, you can be medically underwritten in most states, meaning a pre-existing condition like diabetes, heart disease, or COPD could result in a higher premium or outright denial. If you miss your initial enrollment window, switching plans later becomes much harder unless you qualify for a Special Enrollment Period due to a qualifying event, such as losing employer coverage. Beneficiaries in California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, and Oregon also benefit from a birthday rule that provides a 30-day window each year to switch Medigap plans without medical underwriting — a valuable protection that residents of other states don't have.

One practical step that many beneficiaries overlook is using Medicare's official Plan Finder tool at Medicare.gov to compare Medigap premiums in their specific zip code. Premiums for the exact same standardized plan can vary by 50% or more between insurers in the same market, because while the benefits are identical by law, the pricing is not regulated in most states. Calling your State Health Insurance Assistance Program (SHIP) — a free, unbiased counseling service available in every state — can also help you compare options without the pressure of a sales pitch. SHIP counselors can walk you through the premium differences between Plan G, Plan N, and HD Plan G in your area, explain the rating method each insurer uses, and help you think through which plan fits your health situation and financial comfort level. To find your local SHIP office, visit shiphelp.org or call 1-800-MEDICARE.