Choosing a Medicare Supplement plan in 2026 is one of the most consequential financial decisions a Medicare beneficiary can make, yet it's also one of the most confusing. Original Medicare — Parts A and B — covers roughly 80% of approved medical costs, leaving beneficiaries exposed to hospital deductibles, coinsurance, and unlimited out-of-pocket costs in a serious illness. Medigap policies, sold by private insurers but standardized by the federal government, fill those gaps. In 2026, the most popular and most protective option for newly eligible beneficiaries remains Plan G, while Plan N has emerged as a strong runner-up for those willing to accept modest cost-sharing in exchange for meaningfully lower monthly premiums.
To understand why Plan G dominates, you need to know what it actually covers. In 2026, Plan G pays the Medicare Part A hospital deductible ($1,676 per benefit period), Part A coinsurance and hospital costs up to an additional 365 days after Medicare benefits are exhausted, Part B coinsurance or copayments (that 20% you'd otherwise owe on every doctor visit and outpatient service), 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 does not cover is the Medicare Part B deductible, which is $257 in 2026. Once you've paid that $257 out of pocket at the start of the year, Plan G essentially functions as near-complete coverage for the rest of the year. For someone managing multiple chronic conditions or facing a major surgery, that predictability is worth a great deal.
Plan N covers the same broad list as Plan G with two important differences: it does not cover the Part B deductible ($257), and it does not cover Part B excess charges — the additional amount some doctors who don't accept Medicare assignment can legally charge above Medicare's approved rate, up to 15% more. Plan N also requires a copay of up to $20 for office visits and up to $50 for emergency room visits (waived if you're admitted). In exchange, Plan N premiums are typically $40 to $80 per month lower than Plan G premiums for the same age and zip code. For a 65-year-old in a mid-size city, Plan G might run $140–$180 per month while Plan N runs $100–$140. Over a year, that's a savings of $480 to $960 — real money. The math favors Plan N if you see a doctor fewer than 10–12 times per year and your physicians all accept Medicare assignment, which you can verify at Medicare.gov's Care Compare tool.
Plan F, once the gold standard of Medigap coverage because it also paid the Part B deductible, is no longer available to beneficiaries who became eligible for Medicare on or after January 1, 2020. If you became eligible before that date and already hold a Plan F, you can keep it — and it remains a solid policy. But for anyone newly entering Medicare, Plan F is off the table by federal law, a change Congress made to reduce what it viewed as first-dollar coverage that encouraged overutilization. High-Deductible Plan G (HDG) is worth mentioning for budget-conscious beneficiaries: it carries the same benefits as Plan G but requires you to pay a deductible of $2,870 in 2026 before coverage kicks in. Monthly premiums for HDG can be as low as $30–$60, making it attractive if you're generally healthy and want catastrophic protection without high monthly costs.
Premium pricing for Medigap plans varies significantly by insurer, your age, your sex, your tobacco use, and where you live — even within the same state. Insurers use one of three pricing methods: community-rated (everyone pays the same regardless of age), issue-age-rated (your premium is based on your age when you buy, and doesn't increase just because you get older), and attained-age-rated (premiums increase as you age, which can make policies expensive in your 70s and 80s). Attained-age-rated plans often have the lowest initial premiums but the highest long-term costs. When comparing plans, always ask the insurer which rating method they use. A $20 monthly difference at 65 can become a $100 monthly difference by 75 if one plan is attained-age-rated and the other is community-rated.
The single most important timing rule in Medigap is your Open Enrollment Period. It begins the first day of the month you are both 65 or older AND enrolled in Medicare Part B, and it lasts exactly six months. During this window, insurers must sell you any Medigap policy they offer at standard rates — they cannot reject you or charge you more because of pre-existing conditions. Once this window closes, you lose guaranteed issue rights in most states, meaning insurers can use medical underwriting to deny coverage or charge higher premiums based on your health history. Missing this window is one of the most costly mistakes Medicare beneficiaries make. If you delayed Part B enrollment because you had employer coverage, your six-month Medigap open enrollment window begins when you enroll in Part B, not when you turn 65.
Thirteen states have enacted birthday rules that give existing Medigap policyholders an annual 30-day window around their birthday to switch to a plan with equal or lesser benefits without medical underwriting. Those states are California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, and Oregon. If you live in one of these states and are currently in a higher-premium Medigap plan, your birthday each year is an opportunity to shop for a lower-cost equivalent policy from a competing insurer. New York and Connecticut go further, requiring guaranteed issue year-round regardless of age or health status. If you're in one of these states and have been paying high premiums for years, it's worth getting comparison quotes before your next birthday.
Beyond plan type and timing, the insurer's financial stability and customer service record matter. Medigap benefits are standardized — a Plan G from Company A covers exactly the same services as a Plan G from Company B — so the differentiators are price, rate increase history, and claims processing reputation. AM Best financial strength ratings (look for A- or better) and state insurance department complaint ratios are two useful filters. Your State Health Insurance Assistance Program (SHIP) offers free, unbiased counseling and can pull insurer-specific rate increase histories in your state. To find your local SHIP counselor, visit shiphelp.org or call 1-800-MEDICARE.
One common misconception is that Medigap and Medicare Advantage are interchangeable options you can freely switch between. They are not. Medicare Advantage (Part C) replaces Original Medicare, while Medigap supplements it. You cannot hold both simultaneously. If you're currently in a Medicare Advantage plan and want to switch to Original Medicare plus a Medigap policy, you can disenroll from Medicare Advantage during the Annual Enrollment Period (October 15–December 7) or the Medicare Advantage Open Enrollment Period (January 1–March 31), but you will likely face medical underwriting when applying for Medigap unless you live in a guaranteed-issue state or qualify for a Special Enrollment Period. Planning this transition carefully — ideally before your initial Medicare Advantage enrollment — can save significant money and stress.
For 2026, the bottom line is this: if you want maximum predictability and can afford premiums in the $140–$200 range per month, Plan G is the right choice for most people. If you're in good health, see doctors infrequently, and want to reduce monthly costs, Plan N deserves serious consideration — just confirm your doctors accept Medicare assignment first. If you're on a tight fixed income and primarily want protection against catastrophic costs, High-Deductible Plan G may be worth exploring. Whatever you choose, act during your guaranteed-issue window, compare at least three insurers using your state's Medigap rate comparison tool at Medicare.gov, and consider a free SHIP counseling session before signing anything.