Medicare Supplement Plan M is genuinely one of the least commonly sold Medigap plans available today, and once you see exactly how it’s actually built, it’s easy to understand why that’s the case.
What Plan M Covers
- Medicare Part A coinsurance and hospital costs, plus up to 365 extra days — covered in full
- Medicare Part B coinsurance or copayment — covered in full
- The first 3 pints of blood each year — covered in full
- Part A hospice care coinsurance — covered in full
- Skilled nursing facility coinsurance — covered in full
- 50% of the Medicare Part A deductible
- Foreign travel emergency care, up to plan limits
Plan M simply doesn’t cover the Part B deductible or Part B excess charges at all. In almost every other respect, it’s built exactly like Plan D — same full coverage on Part B coinsurance, same foreign travel benefit. The one and only difference is that Plan D pays 100% of your Part A deductible, and Plan M pays only half.
Why Plan M Rarely Makes Financial Sense
Here’s the problem Plan M runs into: the Part A deductible is charged once per benefit period, not every time you see a doctor, so the actual dollar difference between Plan D (covers it fully) and Plan M (covers half) in a typical year is small — often just half of one Part A deductible. Because that gap is so narrow, carriers usually can’t price Plan M enough below Plan D to make the trade worthwhile; the premium savings frequently don’t come close to offsetting the extra amount you’d pay out of pocket if you’re hospitalized. That mismatch between what Plan M saves you and what it costs you is exactly why so few carriers bother offering it and so few people choose it, even though it’s still technically available.
When Plan M Might Still Be Worth a Look
Occasionally a specific carrier prices Plan M meaningfully below its own Plan D, enough that the premium savings over a year would exceed half of one Part A deductible. In that narrow scenario, Plan M can genuinely be the better deal. It’s not something we’d recommend based on the plan letter alone — we’d only suggest it after directly comparing that carrier’s actual Plan D and Plan M rates side by side.
Availability
Because demand for Plan M is so low, not every carrier offers it, and availability can be inconsistent from year to year even among carriers that do. If you’re specifically interested in Plan M, the first thing we’d check is simply whether any carrier licensed in your county currently sells it, before going any further into the comparison.
Plan M and Medicare Advantage
As with every Medigap plan, Plan M pairs with Original Medicare only, not a Medicare Advantage plan. If you’re weighing Medicare Advantage’s different cost structure — often lower premiums with copays and extra benefits like dental and vision — against a Medigap approach entirely, that’s a separate and larger conversation than comparing Plan M to Plan D specifically.
Common Questions About Plan M
Is Plan M being discontinued?
It’s not officially discontinued, but low demand means fewer carriers actively market it, which can make it feel harder to find than it technically is. It remains part of the standardized Medigap plan lineup nationally.
Should I even ask about Plan M?
It doesn’t hurt to ask us to check — we’ll pull whatever rates are actually available from carriers in your area for both Plan M and Plan D and let the numbers speak for themselves, rather than ruling it out on principle just because it’s uncommon.
Guaranteed Issue Rights
Like the other standardized Medigap plans, Plan M is available without medical underwriting during your 6-month Medigap Open Enrollment Period, which starts the month you’re 65 or older and enrolled in Part B, plus certain other guaranteed-issue situations such as losing employer coverage. Given how few carriers offer Plan M, checking whether you have a guaranteed-issue right matters even more here — if you’d need underwriting anyway, comparing Plan M against every other letter, not just Plan D, becomes worthwhile.
A Straightforward Recommendation
We’ll be direct about this one: in most of the rate comparisons we’ve run, Plan D or Plan G has come out ahead of Plan M for a given carrier, simply because the coverage gap between M and D is so small that carriers rarely discount M enough to matter. We still check the actual numbers every time someone asks, because “usually” isn’t the same as “always,” and your specific carrier’s pricing might be the exception. But we’d rather tell you upfront that Plan M is a long shot than let you assume it’s automatically the budget-friendly choice.
Seeing the Actual Dollar Gap in Practice
It helps to walk through what the “half of one deductible” difference actually looks like. The Medicare Part A deductible applies once per benefit period — essentially once per hospitalization, not once per doctor visit — so in a year with no hospital stay at all, Plan D and Plan M cost you exactly the same amount out of pocket: nothing, on that particular benefit. The only year the difference actually shows up is a year with a qualifying hospital admission, and even then, it’s capped at half of a single deductible, not an open-ended amount. That’s precisely why the premium gap between Plan D and Plan M has to be genuinely meaningful for Plan M to make financial sense — you’re really only comparing “half a deductible, some years” against “a slightly lower premium, every year.”
How Plan M Compares to Plan L and Plan K
People sometimes lump Plan M in with the cost-sharing plans, Plan K and Plan L, since all three ask you to pay a percentage of something. But Plan M’s structure is fundamentally different: it covers your Part B coinsurance in full, with no cost-sharing at all on routine visits, and the only percentage-based cost-sharing anywhere in the plan is that single 50% split on the Part A deductible. Plan K and Plan L, by contrast, apply their cost-sharing percentage across nearly every category of Medicare-covered cost, with an annual limit as the backstop. If you’re drawn to Plan M because “cost-sharing sounds more affordable,” it’s worth understanding that Plan M’s actual exposure is far narrower — and far smaller in dollar terms — than Plan K’s or Plan L’s, which also means the potential savings are narrower too.
What Happens if You Move
Like every Medigap plan, Plan M is guaranteed renewable and works the same way nationwide, since it fills gaps in Original Medicare rather than operating through a local network. If you move to another state, your existing Plan M policy continues to work wherever Medicare is accepted — though given how few carriers offer Plan M in the first place, it’s especially worth checking whether it’s even available at all in a new location before assuming you can simply keep shopping the same plan letter after a move.
A Client Who Asked About Plan M
A client once brought us an advertisement quoting a strikingly low Plan M premium and asked why we hadn’t mentioned it. We pulled that same carrier’s Plan D rate for comparison, and once we walked through what the coverage gap actually amounted to in dollar terms — half of one Part A deductible, in years with a qualifying hospital stay — the premium difference between the two turned out to be larger than that potential gap over a typical multi-year stretch. She ultimately chose Plan D. That’s not true of every carrier in every county, which is exactly why we still pull the actual numbers whenever someone asks about Plan M rather than dismissing it outright.
Plan M and Medicare Advantage Aren’t a Combination
It’s worth stating this plainly, since it’s a point of genuine confusion for some clients: Plan M, like every Medigap plan, only works alongside Original Medicare, not a Medicare Advantage plan. You wouldn’t hold a Plan M policy on top of Medicare Advantage coverage, and it wouldn’t provide any extra benefit even if you tried, since the two aren’t designed to stack together. If you’re currently enrolled in a Medicare Advantage plan and you’re comparing Medigap options as a possible alternative, that’s a genuinely bigger decision involving your specific doctors, your prescriptions, and your current plan’s network — worth a separate, dedicated conversation rather than folding it into a narrow Plan M versus Plan D comparison.
Let Us Check the Real Numbers
If Plan M caught your eye because of a lower advertised premium somewhere, bring us that specific quote — we’ll compare it directly against Plan D from the same or a comparable carrier serving Bethel, Cincinnati, and the rest of Hamilton, Clermont, Butler, and Warren County, so you can see exactly what you’d genuinely be giving up in exchange for what you’d actually be saving, in real dollar terms rather than percentages alone.