If you're turning 65 this year or reviewing your Medicare coverage ahead of 2026, choosing a Medicare Supplement — commonly called Medigap — is one of the most financially significant decisions you'll make. Original Medicare (Parts A and B) covers roughly 80% of approved medical costs, but that remaining 20% has no annual cap. A single hospital stay or serious diagnosis can expose you to thousands of dollars in out-of-pocket costs. Medigap policies, sold by private insurers but standardized by the federal government, are designed to fill those gaps. In 2026, the landscape of available plans, their costs, and the rules governing when you can enroll have some important nuances every beneficiary should understand.
The federal government standardizes Medigap plans by letter — Plans A, B, D, G, K, L, M, and N are available to new enrollees in most states. Plans C and F, which covered the Part B deductible, were eliminated for anyone who became eligible for Medicare on or after January 1, 2020. If you were already enrolled in Plan F before that date, you can keep it. But for the vast majority of people shopping for Medigap in 2026, the real decision comes down to three plans: Plan G, Plan N, and Plan K or L for those seeking lower premiums with higher cost-sharing.
Plan G is the gold standard for comprehensive coverage in 2026. It covers the Part A hospital deductible ($1,676 in 2026), Part A coinsurance and hospital costs, 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 annual Part B deductible, which is $257 in 2026. Once you've paid that deductible out of pocket, Plan G covers essentially everything else Medicare approves. For someone with chronic conditions, frequent specialist visits, or a planned surgery, Plan G can provide enormous financial predictability. Monthly premiums for Plan G vary widely by insurer, age, and location — ranging from roughly $100 to $300 or more per month depending on where you live — but the coverage is identical regardless of which insurer you choose, because the federal government mandates what each lettered plan must cover.
Plan N is the second most popular option and deserves serious consideration if you're in relatively good health and want to reduce your monthly premium. Plan N covers the same broad categories as Plan G, with two key differences: you pay up to a $20 copay for office visits and up to a $50 copay for emergency room visits that don't result in inpatient admission. Plan N also 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 charge. In states where most physicians accept Medicare assignment, excess charges are rare, making Plan N a practical and cost-effective choice. In states like Massachusetts, Minnesota, and Wisconsin — which have their own standardized Medigap systems — the plan structures differ from the federal standard, so beneficiaries there should review their state-specific options carefully.
Plan K and Plan L are worth understanding if budget is your primary concern. Plan K covers 50% of most cost-sharing after the Part A deductible, with an out-of-pocket limit of $7,220 in 2026. Plan L covers 75% of those costs, with an out-of-pocket cap of $3,610 in 2026. Once you hit those caps, the plan pays 100% of covered costs for the rest of the year. These plans carry significantly lower monthly premiums — sometimes $50 to $100 less per month than Plan G — but they expose you to more risk if you have a serious health event. They tend to work best for people who are healthy, have substantial savings to cover potential gaps, and want to minimize their monthly insurance spending.
High-deductible Plan G is another option that has grown in popularity. It works exactly like standard Plan G but requires you to pay a deductible of $2,870 in 2026 before the plan begins paying. In exchange, monthly premiums are dramatically lower — sometimes $30 to $60 per month compared to $150 or more for standard Plan G. If you go a year or two without major medical needs, you come out ahead financially. But if you have a significant health event, you're responsible for that full deductible. This plan suits people who are healthy, want catastrophic protection, and are comfortable managing some financial risk.
The single most important rule about Medigap enrollment is one that surprises many beneficiaries: the Annual Enrollment Period that runs October 15 through December 7 each year — the window most people associate with Medicare plan changes — does not apply to Medigap. Medigap has its own enrollment rules. Your guaranteed-issue window is a six-month period that begins the month you turn 65 and are enrolled in Medicare Part B. During this window, insurers cannot deny you coverage, charge you more based on health conditions, or make you wait for coverage to begin. Once that window closes, insurers in most states can use medical underwriting, meaning they can reject your application or charge significantly higher premiums based on your health history.
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 Medigap plan, your birthday each year triggers a protected window to shop for a better rate or switch insurers — even if your health has changed since you first enrolled. This is a meaningful consumer protection that can save hundreds of dollars annually.
Special Enrollment Periods for Medigap also exist in specific circumstances. If you lose employer-sponsored coverage, move out of a Medicare Advantage plan's service area, or your current Medigap insurer goes bankrupt, you may qualify for a guaranteed-issue SEP that lets you enroll in certain Medigap plans without underwriting. The specific plans available under SEP protections are typically Plans A, B, C, F, K, and L — not Plan G or N — so understanding which plans are guaranteed-issue in your situation matters.
Pricing is where beneficiaries often get confused, because the same Plan G from two different insurers can have very different premiums — and those premiums can grow at very different rates over time. Insurers use three pricing methods: community-rated (everyone pays the same regardless of age), issue-age-rated (your premium is based on your age when you first enroll and doesn't increase as you age), and attained-age-rated (your premium increases as you get older). Attained-age-rated plans often have the lowest initial premiums but can become the most expensive over time. Community-rated plans, common in states like New York and Connecticut, may seem expensive at 65 but become relatively affordable at 80. When comparing plans, ask each insurer which pricing method they use and request their rate increase history for the past five years.
One practical strategy many beneficiaries overlook: because Medigap benefits are federally standardized, you are essentially shopping for the same product at different prices. Tools like the Medicare Plan Finder at Medicare.gov allow you to compare Medigap premiums by zip code, and your State Health Insurance Assistance Program (SHIP) — a free, federally funded counseling service — can walk you through local options without any sales pressure. SHIP counselors are available in every state and can be reached through the Eldercare Locator at 1-800-677-1116. Unlike insurance agents, SHIP counselors have no financial incentive to steer you toward any particular plan.
For 2026, the most common recommendation from independent Medicare counselors for new enrollees who want comprehensive coverage is Plan G from a financially stable insurer with a strong rate-increase history. For healthier beneficiaries who want to reduce monthly costs and are comfortable with modest copays, Plan N is a strong alternative. The worst financial outcome for most beneficiaries is staying in Original Medicare alone without any supplement — because that 20% coinsurance with no cap can translate into tens of thousands of dollars in exposure during a serious illness. Whatever plan you choose, locking in coverage during your guaranteed-issue window at 65 is almost always preferable to waiting and facing medical underwriting later.