Medigap Plan F vs. Plan G: Which One Covers More of Your Bills?

If you've been shopping for a Medicare supplement plan — also called Medigap — you've almost certainly come across Plan F and Plan G. These two plans sit at the top of the Medigap lineup in terms of coverage, and for good reason: both protect you from the kind of large, unpredictable out-of-pocket costs that can turn a hospital stay into a financial crisis. But they are not the same plan, they don't cost the same, and — critically — not everyone is even eligible for both. Understanding the real difference between them could save you hundreds of dollars a year or protect you from a coverage gap you didn't know existed.

Let's start with who can actually buy Plan F. As of January 1, 2020, Plan F is no longer available to newly eligible Medicare beneficiaries. That means if you turned 65 on or after January 1, 2020, or became eligible for Medicare due to a disability after that date, Plan F is simply off the table for you. This change came from the Medicare Access and CHIP Reauthorization Act (MACRA), which eliminated Medigap plans that cover the Part B deductible for new enrollees. If you were already enrolled in Medicare before 2020, you can still purchase Plan F — and if you already have it, you can keep it. But for the majority of people shopping for Medigap today, Plan G is the most comprehensive option available.

So what exactly does each plan cover? Plan F is often described as "first-dollar coverage" because it pays virtually every Medicare-approved cost that Original Medicare doesn't cover. That includes the Medicare Part A hospital deductible (which is $1,676 per benefit period in 2025), the Part A coinsurance for extended hospital stays, skilled nursing facility coinsurance, the Part B deductible ($257 in 2025), Part B coinsurance and copayments, Part B excess charges (when a doctor charges more than Medicare's approved amount), foreign travel emergency care (up to plan limits), and the first three pints of blood. You pay your monthly premium and essentially nothing else for covered services.

Plan G covers every single one of those same benefits — with one exception. Plan G does not cover the Medicare Part B deductible, which is $257 in 2025. That's it. That's the entire difference between these two plans. You pay that $257 deductible once per calendar year before Plan G kicks in for outpatient services, and after that, your coverage is identical to Plan F. This means that if you see a doctor in January and pay your $257 deductible, every subsequent outpatient visit, lab test, imaging study, and specialist appointment for the rest of that calendar year is covered at 100% of the Medicare-approved amount — assuming your providers accept Medicare assignment.

Here's where the financial math becomes important. Because Plan F covers that $257 deductible and Plan G does not, insurance companies charge more for Plan F. The premium difference varies by insurer, your age, your location, and whether you choose a community-rated, issue-age-rated, or attained-age-rated pricing structure. But in practice, the annual premium difference between Plan F and Plan G from the same insurer for the same enrollee typically ranges from $300 to $600 per year — and in some markets, it's even higher. If you're paying $400 more per year for Plan F to avoid a $257 deductible, you are spending $143 more than the benefit is worth. Over five years, that's $715 out of pocket more than you needed to spend. The math almost always favors Plan G for people who are newly eligible.

There's another long-term concern with Plan F that deserves serious attention: adverse selection. Because Plan F is closed to new enrollees, the pool of people who hold Plan F policies is aging and shrinking every year. Healthier, younger Medicare beneficiaries are enrolling in Plan G instead. This means the Plan F risk pool is gradually becoming older and sicker on average, which puts upward pressure on Plan F premiums over time. Several actuarial analyses have projected that Plan F premiums will rise faster than Plan G premiums in the coming years for exactly this reason. If you're currently on Plan F and your premium has been climbing steeply, this is likely part of why — and it's worth comparing what Plan G would cost you today from a competing insurer.

Switching from Plan F to Plan G is possible, but it comes with an important caveat: in most states, you'll need to pass medical underwriting if you're outside your guaranteed issue window. That means the insurance company can review your health history and potentially deny you coverage or charge you a higher premium based on pre-existing conditions. Your guaranteed issue window is typically the six months following your Part B enrollment start date — that's when insurers must sell you any Medigap plan at standard rates regardless of your health. Outside that window, your options depend heavily on which state you live in. Thirteen states have enacted a "birthday rule" that gives you a 30-day window each year around your birthday to switch Medigap plans without medical underwriting: 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 you're currently on Plan F, your birthday window may be your best opportunity to compare Plan G rates and switch without health questions.

High-deductible versions of both plans also exist and are worth mentioning. High-Deductible Plan F and High-Deductible Plan G require you to pay a deductible — $2,870 in 2025 — before the plan begins paying. In exchange, monthly premiums are significantly lower, sometimes $40–$80 per month compared to $150–$250 or more for standard Plan G. These high-deductible options can make sense for relatively healthy beneficiaries who want catastrophic protection without paying high monthly premiums, but they require you to be comfortable absorbing several thousand dollars in costs in a bad year. High-Deductible Plan G is available to all new enrollees; High-Deductible Plan F carries the same eligibility restriction as standard Plan F.

When comparing specific plans, always request quotes from multiple insurers for the same plan letter. Because Medigap benefits are standardized by federal law — meaning Plan G from Company A covers exactly the same services as Plan G from Company B — the only meaningful differences are the monthly premium, the insurer's financial stability rating, and their history of rate increases. Tools like the Medicare Plan Finder at Medicare.gov and your State Health Insurance Assistance Program (SHIP) can help you compare options at no cost. SHIP counselors are trained, unbiased, and free — they can walk you through quotes side by side and help you understand the rate increase history of specific insurers in your area. To find your local SHIP office, visit shiphelp.org or call 1-800-MEDICARE.

One more consideration: if you're approaching 65 and enrolling in Medicare for the first time, the window to enroll in Medigap without medical underwriting is precious. Don't let it pass without making a deliberate decision. Even if you're healthy and rarely use medical care, the protection that Plan G provides against a single major hospitalization — which could otherwise cost you thousands in Part A deductibles and coinsurance — can be worth every dollar of the monthly premium. The average Medicare beneficiary has 2.3 chronic conditions, and healthcare needs tend to increase with age. Locking in a Medigap policy while you're healthy and during your guaranteed issue window gives you the most options at the lowest cost.