The Price Tag You See Is Not the Price You Pay
Most people shopping for a Medicare supplement plan focus entirely on the monthly premium. That’s understandable. It’s the number that shows up in every comparison chart, and it’s the number that agents lead with. But it’s only part of what you’ll actually spend.
I’ve watched people pick the cheapest Plan G they could find, feeling good about saving $40 a month, and then get blindsided by costs they didn’t know existed. The premium is real money, yes. So is everything else I’m about to walk you through.
The hidden costs of Medicare supplement plans fall into a few distinct categories: costs built into how Original Medicare works, costs that come from the plan’s structure, costs that grow over time in ways people don’t anticipate, and coverage gaps that most people assume don’t exist. Let’s go through all of them.
The Part B Deductible Is the Cost That Surprises Plan G Buyers Most
Here’s something a lot of new Medicare enrollees don’t realize: Plan G, which is currently the most popular Medigap plan on the market, does not cover the Part B deductible. Plan F does, but Plan F is only available if you became eligible for Medicare before January 1, 2020. If you aged in after that, Plan G is essentially the top tier available to you.
The 2026 Part B deductible is $257. You pay that out of pocket before Medicare starts covering your outpatient costs for the year. That’s not a huge number, but it’s also not zero, and a lot of people buying Plan G genuinely believe they have no deductible at all. They find out they’re wrong at their first doctor’s visit in January.
There’s also the Part A deductible, which works differently. In 2026, the Part A inpatient hospital deductible is $1,676 per benefit period, not per year. That distinction matters a lot. If you’re hospitalized, discharged, and then readmitted more than 60 days later, that deductible resets. Plan G covers this deductible completely, which is actually one of its strongest selling points. But for Plan N buyers, the story gets more complicated.
Plan N doesn’t cover the Part B deductible either, and it also comes with copays: up to $20 for doctor visits and up to $50 for emergency room visits that don’t result in an inpatient admission. If you’re someone with three or four specialist visits a year, those $20 copays add up faster than the premium savings justify. I’ve run the math with real people in this situation, and Plan G often wins on total annual cost even when Plan N’s premium is $30-$40 lower per month.
Rate Increases Are Predictable, But People Don’t Plan for Them
This is the one that genuinely frustrates me, because it’s avoidable with the right information upfront.
Medigap premiums go up every year. Every insurer raises rates, and they do it for two reasons: general medical inflation, and the fact that their existing policyholders are getting older and using more care. If you locked in a Plan G at $140 a month at age 65, don’t expect it to stay there. By the time you’re 72 or 73, it’s not unusual to see that same plan at $190 or $210 per month with the same carrier.
How fast premiums increase depends heavily on how your plan is priced. There are three pricing structures: attained-age, issue-age, and community-rated. Attained-age pricing ties your premium directly to your current age, so it increases every year you get older on top of general rate increases. Issue-age pricing locks your rate to the age when you first enrolled, so it only goes up with inflation, not with your birthday. Community-rated pricing charges everyone in the area the same rate regardless of age.
| Pricing Type | How Rate Is Calculated | Long-Term Cost Risk | Common In |
|---|---|---|---|
| Attained-Age | Based on your current age each year | Highest | Most states |
| Issue-Age | Based on your age when you enrolled | Moderate | Select states (FL, CA, etc.) |
| Community-Rated | Same for everyone in the area | Lowest age-related risk | CT, MA, MN, NY, WA |
Most people don’t ask which pricing structure they’re buying. Agents don’t always volunteer it. If you’re 65 and buying an attained-age Plan G, you’re starting with a lower premium than an issue-age plan, but you’re setting yourself up for steeper increases every single year. Over a 15-year retirement, that really matters.
My advice: if you’re in a state that allows issue-age or community-rated pricing, factor that into your comparison. The first-year premium isn’t the whole picture.
The Biggest Misconception: Medigap Covers Everything Original Medicare Doesn’t
I hear this constantly, and it’s wrong in ways that can genuinely hurt people financially.
Medigap supplements Original Medicare. It does not replace it. That means if Original Medicare doesn’t cover something, your Medigap plan almost certainly doesn’t cover it either. The supplemental coverage fills Medicare’s cost-sharing gaps. It doesn’t add new benefits.
The biggest categories that fall completely outside both Original Medicare and Medigap coverage include dental, vision, hearing aids, and long-term care. These aren’t small things. A single hearing aid can cost $2,000 to $5,000. Dental work in your 70s, when root canals and crowns become more common, can run several thousand dollars a year. None of that touches your Medigap plan.
There’s also no prescription drug coverage in any Medigap plan. Not one. You need a separate Part D plan for that. People who don’t enroll in Part D during their initial enrollment window face a lifetime late enrollment penalty: 1% of the national base beneficiary premium for every month they went without coverage. That penalty stacks on top of your Part D premium forever. For someone who waits two years to enroll, that’s a 24% permanent premium increase. It’s not capped. It doesn’t go away.
Beyond those big gaps, Original Medicare itself has coverage limits that Medigap inherits. Skilled nursing facility care beyond 100 days isn’t covered. Most custodial care isn’t covered. Foreign emergency care is only covered by some Medigap plans (Plans C, D, F, G, M, and N offer a foreign travel emergency benefit with a $250 deductible and 80% coverage up to a $50,000 lifetime limit). If you travel internationally and pick Plan K or Plan L because they’re cheaper, you have no foreign emergency coverage at all.
Switching Plans Later Is Harder Than People Expect
Here’s the thing most people don’t find out until it’s too late to do anything about it. When you first enroll in Medicare Part B, you have a six-month open enrollment window for Medigap. During that window, insurers cannot deny you coverage or charge you more based on your health history. You can buy any plan available in your state, no questions asked about preexisting conditions.
Once that window closes, you’re subject to medical underwriting in most states. That means if you have diabetes, heart disease, a history of cancer, or dozens of other conditions, insurers can legally decline your application or charge you significantly higher premiums. In many cases, people who didn’t choose the right plan at 65 find themselves stuck with it at 72 because they can’t pass underwriting to switch.
This is why I tell people to think hard at the front end. Don’t buy Plan N to save $35 a month if there’s a real chance you’ll want Plan G coverage in five years and won’t be able to get it. The savings aren’t worth the lock-in risk for most people.
A 67-year-old in Ohio who buys Plan N because the premium looks attractive, gets diagnosed with a chronic condition at 70, and then can’t switch to Plan G is going to spend years paying those copays while watching Plan G buyers pay nothing at the point of care. That’s not hypothetical. It’s a pattern I’ve seen repeat itself more times than I can count.
There are some exceptions. A few states, including New York and Connecticut, have guaranteed issue protections year-round that allow switching without underwriting. If you live in one of those states, this risk doesn’t apply to you the same way. But in most of the country, you don’t get a second chance without passing a health screening.
Bottom Line
For most people, Plan G is worth the higher premium because it eliminates almost all out-of-pocket costs except the 2026 Part B deductible of $257, and it removes the underwriting risk that comes with trying to upgrade later. Don’t let a $30-per-month premium difference push you into Plan N unless you’re genuinely healthy, expect to stay that way, and have done the math on your actual visit patterns. The hidden costs in Medigap aren’t impossible to manage, but you have to know they exist before you can account for them.
Frequently Asked Questions
Does Medicare supplement cover dental and vision?
No. Neither Original Medicare nor any Medigap plan covers routine dental, vision, or hearing care. If you want those benefits, you need to purchase standalone dental and vision insurance or look at Medicare Advantage, which sometimes bundles those benefits but works very differently from Medigap.
Will my Medigap premium go up every year?
Almost certainly yes. All Medigap insurers raise rates annually. How fast depends on your plan’s pricing structure. Attained-age plans increase every year you get older plus general medical inflation. Issue-age and community-rated plans typically increase more slowly. Ask your insurer which structure your plan uses before you sign up.
Can I be denied Medigap coverage after my open enrollment period?
In most states, yes. After your six-month Medigap open enrollment window closes, insurers can use medical underwriting to deny your application or charge you higher premiums based on your health history. There are limited guaranteed issue rights in specific circumstances, but they don’t protect most people who simply want to switch plans years after their initial enrollment.
Is there a deductible with Plan G?
Plan G covers the Part A deductible ($1,676 per benefit period in 2026) but does not cover the Part B deductible ($257 in 2026). So you’ll pay that $257 yourself before your outpatient coverage kicks in each calendar year. There is also a high-deductible version of Plan G with a 2026 deductible of $2,870, after which the plan pays everything Plan G normally covers. That version makes sense for very healthy people who want a low premium and can absorb the front-end risk.
