If you've spent any time researching Medicare supplement insurance, you've almost certainly come across Plan G. Since Plan C and Plan F were closed to new enrollees who turned 65 after January 1, 2020, Plan G has become the gold standard for comprehensive Medigap coverage. It fills in nearly every gap that Original Medicare leaves behind — and for beneficiaries who use significant healthcare services, it can provide real financial predictability. But it's not the right choice for everyone, and the premium you pay matters just as much as the coverage you get.
To understand why Plan G is so popular, you first need to understand what Original Medicare actually leaves you responsible for. Medicare Part A — your hospital coverage — comes with a deductible of $1,676 per benefit period in 2025. That's not an annual deductible; it resets every time you start a new benefit period, which means a serious illness with multiple hospitalizations could trigger that deductible more than once in a single year. Part A also leaves you responsible for coinsurance after 60 days in the hospital: $419 per day for days 61–90, and $838 per day for so-called lifetime reserve days. Plan G covers all of that. It also covers skilled nursing facility coinsurance ($209.50 per day for days 21–100 in 2025), Part B coinsurance (typically 20% of all outpatient costs), Part B excess charges, foreign travel emergency care (up to plan limits), and the first three pints of blood. The only thing Plan G does not cover that you'll pay out of pocket is the Part B deductible, which is $257 in 2025.
That single gap — the $257 Part B deductible — is what separates Plan G from the now-closed Plan F. Plan F covered everything, including that deductible. But because Plan F is no longer available to newly eligible Medicare beneficiaries, Plan G has stepped into the role of most-comprehensive available plan. For most people, paying $257 once a year out of pocket is a reasonable trade-off, especially since Plan G premiums are typically lower than what Plan F premiums have become as that pool of enrollees ages and their claims rise.
So what does Plan G actually cost? This is where things get complicated — and where many beneficiaries make expensive mistakes by accepting the first quote they receive. Premiums for Plan G vary significantly based on where you live, your age, your gender, whether you smoke, and which insurance company you choose. In 2025, monthly premiums for a 65-year-old non-smoking woman can range from around $100 per month in some states to well over $250 per month in higher-cost markets like New York or Florida. Men typically pay somewhat more. The same Plan G benefits are standardized by federal law — every insurer must offer the same coverage — but the price is not standardized at all. Two insurers in the same zip code can charge dramatically different premiums for identical coverage.
Insurers also use different pricing methods, called rating structures, that affect how your premium changes as you age. Community-rated plans charge everyone in a geographic area the same premium regardless of age — your rate goes up only due to inflation and claims trends, not because you're getting older. Issue-age-rated plans set your premium based on how old you are when you first enroll, and that rate also increases only with inflation. Attained-age-rated plans start lower but increase as you age, which can make them look attractive at 65 but significantly more expensive by your mid-70s. Understanding which rating method an insurer uses is critical to projecting your long-term costs, not just your first-year premium.
There's also a high-deductible version of Plan G worth knowing about. High-Deductible Plan G carries the same benefits as standard Plan G, but you pay all costs out of pocket until you've met a deductible — $2,870 in 2025 — before the plan kicks in. In exchange, the monthly premium is dramatically lower, often $30 to $60 per month depending on your state and insurer. This version can make sense for beneficiaries who are generally healthy, have some savings to cover the deductible if needed, and want protection against catastrophic costs without paying high monthly premiums. It functions somewhat like a high-deductible health plan in the employer market — lower cost when you're well, meaningful protection when you're not.
The most important thing to understand about enrolling in Plan G — or any Medigap policy — is that your right to buy it without answering health questions is time-limited. Federal law guarantees you a six-month Medigap Open Enrollment Period that begins the month you are both 65 or older and enrolled in Medicare Part B. During that window, no insurer can deny you coverage or charge you more based on your health history. Once that window closes, insurers in most states can use medical underwriting, meaning they can reject your application or charge higher premiums if you have conditions like diabetes, heart disease, COPD, or a history of cancer. If you miss your open enrollment window and later develop health problems, you may find yourself locked out of comprehensive Medigap coverage entirely.
Some states offer additional protections. If you live in California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, or Oregon, you have what's known as a birthday rule — a 30-day window each year around your birthday during which you can switch Medigap plans without medical underwriting. New York and Connecticut go further, requiring guaranteed issue for Medigap year-round. If you live in one of these states, you have more flexibility to switch plans if you find a better price later. If you don't, your initial enrollment decision carries much more long-term weight.
Comparing Plan G to Medicare Advantage is a question many beneficiaries wrestle with. Medicare Advantage plans often have $0 premiums and include extras like dental and vision, which makes them look attractive on paper. But Medicare Advantage plans use networks, require referrals in some cases, and expose you to cost-sharing — copays, coinsurance, and out-of-pocket maximums that can reach $8,850 or more for in-network care in 2025. Plan G, paired with Original Medicare, gives you access to any provider in the country who accepts Medicare, with no network restrictions and highly predictable costs. For beneficiaries who travel frequently, have complex health needs, or simply want certainty about what they'll owe, Plan G's structure is often the more financially protective choice — even at a higher monthly premium.
To find the best Plan G rate in your area, use Medicare's official Plan Finder tool at medicare.gov or contact your State Health Insurance Assistance Program (SHIP), which provides free, unbiased counseling. SHIP counselors can walk you through premium comparisons, explain rating structures, and help you evaluate whether Plan G, High-Deductible Plan G, or another Medigap option fits your situation. You can find your local SHIP contact through the Eldercare Locator at eldercare.acl.gov or by calling 1-800-MEDICARE. Getting at least three to five premium quotes before enrolling — and asking each insurer which rating method they use — can potentially save you hundreds of dollars per year over the life of your coverage.