Medicare Supplement Plan M: Coverage and Costs Explained

What Plan M covers in 2026

Medigap is private insurance that helps pay your share of costs in Original Medicare (Parts A and B). Every Medigap plan sold under a given letter is federally standardized, so a Plan M from one insurer covers the same core benefits as a Plan M from any other — only the premium and service differ.

Plan M is built around partial cost-sharing on the front end. It pays several benefits in full but splits the Part A deductible with you and leaves the Part B deductible entirely to you. That trade-off is what keeps its premium lower than first-dollar plans.

• Part A hospital coinsurance plus an extra 365 days after Medicare benefits run out: paid 100%
• Part B coinsurance or copayment (the 20% you normally owe after the Part B deductible): paid 100%
• First 3 pints of blood: paid 100%
• Part A hospice care coinsurance or copayment: paid 100%
• Skilled nursing facility coinsurance (the $217/day charge for days 21–100): paid 100%
• Part A deductible: paid 50% — Plan M covers $868 of the $1,736 benefit-period deductible, leaving you the other $868
• Foreign travel emergency care: paid 80% after a $250 deductible, up to a $50,000 lifetime maximum

What Plan M does not cover

Two gaps define Plan M. First, it does not pay the annual Part B deductible — $283 in 2026 — so you pay that out of pocket before Plan M starts covering your Part B coinsurance. By law, no Medigap plan sold to people newly eligible on or after January 1, 2020 can cover the Part B deductible, so this is not unique to Plan M.

Second, Plan M does not cover Part B excess charges — the extra amount (up to 15%) a provider who does not accept Medicare assignment can legally bill above the approved rate. If you use providers who accept assignment, this gap rarely matters in practice, but it is a real difference from plans G and F.

Plan M is also not a drug plan. Like all Medigap policies sold today, it does not include Part D prescription coverage, so most enrollees pair it with a standalone Part D plan.

What Plan M actually costs you

Plan M has no government-set price. Premiums are set by each insurer and vary widely by company, your age, ZIP code, tobacco use, and how the policy is rated (issue-age, attained-age, or community-rated). Because of the cost-sharing, Plan M premiums generally run lower than Plan G or Plan F from the same insurer, though the exact spread varies by plan and market.

On top of any Medigap premium, you still pay your standard Part B premium — $202.90 per month in 2026 — plus your Part D drug-plan premium if you have one. Higher-income enrollees may also owe an income-related adjustment (IRMAA) on Parts B and D.

The clearest way to think about Plan M's value is the two costs it leaves with you: half of the Part A deductible ($868) per benefit period if you are hospitalized, and the full Part B deductible ($283) each year. If you rarely expect inpatient stays, those exposures may be smaller than the premium savings.

How Plan M compares to similar plans

Plan M sits between the fuller plans and the high-deductible cost-sharing plans. Compared with Plan G, Plan M gives up coverage of half the Part A deductible and of Part B excess charges in return for a typically lower premium; otherwise the two are similar on the big-ticket Part A and Part B coinsurance.

Compared with Plans K and L, Plan M does not have an annual out-of-pocket limit. Plans K and L cap your yearly spending (after which they pay 100%), but they cover a smaller share of many benefits along the way. Plan M instead pays most benefits in full and concentrates its cost-sharing on the Part A and Part B deductibles.

• Plan M has no yearly out-of-pocket maximum — unlike Plans K and L
• Plan M pays Part B coinsurance at 100%, like Plans G and N
• Plan M is one of the least-offered Medigap plans, so availability from insurers in your area may be limited

Who Plan M may suit

Plan M can make sense for someone who wants strong protection against large hospital and outpatient coinsurance bills but is comfortable absorbing the smaller, predictable deductibles in exchange for a lower premium. It can be especially worth comparing if you travel internationally, since it includes the 80% foreign travel emergency benefit.

Whether Plan M beats Plan G or N for you comes down to local premium quotes and how often you expect inpatient care. Coverage is identical across insurers for the same letter, so once you have decided on Plan M, compare prices and the insurer's rate-increase history rather than the benefits themselves. Plan availability and pricing vary by state and insurer.