If you've been shopping for a Medicare Supplement plan — also called Medigap — in 2025, you've probably noticed that the price quotes you're getting vary wildly. One insurer might quote you $140 a month for Plan G. Another quotes $220 for the exact same plan letter. A third wants $310. All three are technically selling the same standardized coverage. So what's going on, and what should you actually expect to pay?
The short answer is that Medigap premiums in 2025 depend on five key variables: the plan letter you choose, your age, your sex, whether you smoke, and where you live. Insurers are allowed to use all of these factors when setting premiums, and the differences can be dramatic. A 65-year-old woman in Iowa might pay $105 per month for Plan G, while a 72-year-old man in South Florida could pay $290 or more for identical coverage. That's not a scam — it's how the Medigap market is legally structured.
Let's start with the plan letters that matter most in 2025. Plans C and F — which covered the Medicare Part B deductible — are no longer available to people who became eligible for Medicare on or after January 1, 2020. That means most new enrollees are choosing between Plan G, Plan N, and Plan D, with Plan G dominating the market. Plan G covers virtually everything Original Medicare doesn't: the Part A hospital deductible ($1,676 in 2025), 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 thing Plan G does not cover is the annual Part B deductible, which is $257 in 2025. You pay that once per year, and then Plan G handles the rest.
For Plan G specifically, national average premiums in 2025 run roughly $120 to $200 per month for a 65-year-old woman who doesn't smoke, based on rate filings and market surveys. Men typically pay 5–15% more than women of the same age for the same plan. By age 70, those same Plan G premiums often climb to the $160–$250 range. By 75, expect $200–$320 or more in many states. These aren't scare numbers — they're the reality of attained-age pricing, which is the most common pricing method insurers use. Under attained-age pricing, your premium increases each year as you get older, in addition to any general rate increases the insurer files with your state insurance department.
Plan N is the second most popular option and deserves serious consideration if you're in good health and don't mind modest cost-sharing at the point of care. Plan N premiums typically run 15–25% lower than Plan G in the same market. For a 65-year-old woman, that might mean $95–$160 per month instead of $120–$200. The trade-off: Plan N requires a copay of up to $20 for office visits and up to $50 for emergency room visits that don't result in a hospital 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 legally charge. If you live in a state where most physicians accept Medicare assignment, excess charges are rarely an issue. If you see specialists frequently or live in a market with many non-participating providers, Plan G's complete coverage may be worth the higher premium.
Plan D is a lesser-known option that covers the same benefits as Plan N but without the office visit and ER copays — and without excess charge coverage either. Plan D premiums tend to fall between Plan N and Plan G in most markets. It's worth getting a quote if you want to avoid copays but don't want to pay full Plan G rates.
According to CMS.gov data from the 2024 Medicare Supplement enrollment landscape, approximately 14.4 million Medicare beneficiaries were enrolled in a Medigap policy as of mid-2024. Plan G accounted for the largest share of new enrollments among beneficiaries who became eligible after 2020, reflecting its position as the de facto replacement for the discontinued Plan F. The average monthly premium paid across all Medigap plan letters and all ages was approximately $183, though that figure blends together 65-year-olds paying $110 and 80-year-olds paying $350, so it's more useful as a reference point than a planning number.
One factor that significantly affects your long-term cost is the pricing method your insurer uses. There are three types: community-rated (everyone in the same geographic area pays the same premium regardless of age), issue-age-rated (your premium is based on your age when you first buy the policy and doesn't increase just because you get older), and attained-age-rated (your premium increases as you age). Community-rated plans may seem expensive at 65 but become the best value by your mid-70s. Attained-age plans often look cheapest at enrollment but can become significantly more expensive over time. Only a handful of states — including New York, Connecticut, Massachusetts, and Minnesota — require community rating for all Medigap policies. In most states, attained-age pricing dominates the market, which is why it's worth asking every insurer which method they use before you sign up.
Household discounts are another underutilized way to reduce your Medigap premium. Many insurers offer a 5–7% discount if two people in the same household both purchase a policy from the same company. If you and your spouse are both enrolling in Medigap, always ask about household discounts — they can add up to hundreds of dollars per year.
The single most important timing decision you'll make about Medigap is when you enroll. During your 6-month Medigap Open Enrollment Period — which starts the first month you're both 65 and enrolled in Medicare Part B — insurers cannot deny you coverage or charge you more based on your health history. This is your guaranteed issue window. Once it closes, most states allow insurers to use medical underwriting, meaning they can reject your application or charge higher premiums if you have pre-existing conditions like diabetes, heart disease, or a history of cancer. If you miss this window, getting affordable Medigap coverage can become genuinely difficult in most states.
There are some exceptions worth knowing. If you lose employer-sponsored coverage, disenroll from a Medicare Advantage plan during certain windows, or move out of your plan's service area, you may qualify for a Special Enrollment Period that restores your guaranteed issue rights. These SEPs are specific and time-limited — typically 63 days from the triggering event — so acting quickly matters.
Thirteen states have what's known as a birthday rule, which gives Medigap enrollees a 30-day window each year around their birthday to switch to a plan with equal or lesser benefits from any insurer 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 feel locked into a high-premium policy, your birthday window may give you a path to a lower rate — especially if you've been healthy since you first enrolled.
When you're comparing quotes, use Medicare.gov's Medigap policy search tool, which lets you enter your ZIP code and see every insurer offering coverage in your area along with their plan letters and monthly premiums. This is the most reliable starting point because it pulls from state-filed rate data. From there, it's worth calling two or three of the lower-cost insurers directly to confirm the quote and ask about their rate increase history. An insurer with a low introductory premium but a history of 8–10% annual increases may cost more over five years than a competitor charging $20 more per month today with a track record of 3–4% annual increases. Rate stability is a real factor that the premium quote alone won't tell you.
Finally, it's worth being clear about what Medigap does not cover, so you're not caught off guard. Medigap plans do not include prescription drug coverage — you'll need a separate Part D plan for that. They don't cover dental, vision, or hearing care. They don't cover long-term custodial care. And they don't work alongside Medicare Advantage plans — you can only use Medigap with Original Medicare (Parts A and B). If you're currently in a Medicare Advantage plan and considering a switch to Original Medicare plus Medigap, be aware that in most states you'll face medical underwriting unless you qualify for a guaranteed issue SEP.
The bottom line for 2025: a healthy 65-year-old enrolling during their Open Enrollment Period can typically find solid Plan G coverage for $120–$180 per month in most parts of the country, with Plan N available for $95–$155. Those premiums will rise with age, but for beneficiaries who want predictable out-of-pocket costs and the freedom to see any Medicare-accepting provider in the country without referrals or network restrictions, Medigap remains one of the most straightforward ways to control healthcare spending in retirement.