Most Medigap conversations revolve around Plan G and Plan N, but three other standardized plans exist — K, L, and M — designed for people who want a lower monthly premium in exchange for sharing a portion of costs with Medicare. This guide explains how that shared cost-sharing works, what the annual out-of-pocket limit on Plans K and L means, why Plan M covers only half the Part A deductible, and how to decide whether any of the three fits you.
What all three plans have in common
Plan K, Plan L, and Plan M all cover Part A hospital coinsurance at 100% and add 365 extra days of hospital coverage after Medicare benefits run out, the same as every other Medigap plan. None of the three cover the annual Part B deductible or the Part B excess charge, so if those two items are your top priority, Plan G remains the most complete option available to new beneficiaries.
Availability, cost, benefits, and eligibility vary by person, product, contract, and insurance company, as well as by your service area. Guarantees are subject to the claims-paying ability of the issuing insurance company. Karla Arámburo is not affiliated with or endorsed by Medicare or the federal government.
Plan K: the lowest premium, with an out-of-pocket limit
Plan K covers 100% of Part A hospital coinsurance, but only 50% of Part B coinsurance, 50% of the Part A hospital deductible, 50% of skilled nursing facility coinsurance, and 50% of the first three pints of blood. In exchange for that shared cost-sharing, Plan K generally carries the lowest monthly premium among the broad-coverage Medigap plans.
What makes Plan K manageable is its annual out-of-pocket limit, set by Medicare each year. Once you've personally paid that amount in Medicare-covered shared costs within the calendar year, Plan K pays 100% of Medicare-covered costs for the rest of the year. That limit acts as a safety net: your maximum risk in a bad year is capped, even though your typical monthly costs run higher than under Plan G.
Plan L: more generous cost-sharing, lower limit
Plan L works the same way as Plan K, but covers 75% instead of 50% of Part B coinsurance, the Part A deductible, skilled nursing facility coinsurance, and blood. Because the plan takes on more of the shared cost, your portion is smaller at each visit, and Plan L's annual out-of-pocket limit is lower than Plan K's, though its monthly premium usually runs higher than Plan K's.
Plan M: almost like Plan D, with a twist on the Part A deductible
Plan M covers almost everything at 100%, similar to Plan D: Part A hospital coinsurance, Part B coinsurance, skilled nursing facility coinsurance, and blood. The one difference is that Plan M covers only 50% of the Part A hospital deductible, while Plan D covers it at 100%. Plan M has no annual out-of-pocket limit, because it covers nearly all other costs without shared coinsurance.
Comparison table: Plan K vs. Plan L vs. Plan M
| Benefit | Plan K | Plan L | Plan M |
|---|---|---|---|
| Hospital coinsurance (Part A) | 100% | 100% | 100% |
| Part A deductible | 50% | 75% | 50% |
| Part B coinsurance | 50% | 75% | 100% |
| Part B deductible | Not covered | Not covered | Not covered |
| Part B excess charge | Not covered | Not covered | Not covered |
| Skilled nursing facility care | 50% | 75% | 100% |
| Annual out-of-pocket limit | Yes (higher) | Yes (lower) | No |
| Typical monthly premium | Lowest of the three | Middle | Highest of the three, but lower than Plan D |
How to decide whether one of these plans fits you
If your top priority is the lowest possible monthly premium and you can handle variable coinsurance, with the peace of mind of an annual limit capping your risk, Plan K is worth reviewing. If you'd rather share less cost per visit but still want that annual limit, Plan L is a reasonable middle ground. If you want coverage nearly as complete as Plan D but with a somewhat lower premium, and can handle 50% of the Part A deductible as your one real exposure, Plan M is worth comparing.
Because these three plans aren't as common as Plan G or Plan N, the practical first step is confirming which specific insurers sell them in your ZIP code and at what price. If you want to understand how Medigap works in general first, review our general Medigap guide, or compare Plan G against Plan N if you'd rather see one of the broader-coverage options.
Free bilingual help deciding
I am Karla Arámburo, an independent, bilingual insurance agent licensed to serve families in Orange, Los Angeles, San Diego, and Riverside counties. I review your budget, your doctor-visit history, and your risk tolerance to help you compare Plan K, Plan L, and Plan M against Plan G and Plan N, in Spanish or English, at no cost to you. As an independent agent, I compare specific insurers available for your ZIP code, not just one plan.
You can call or text (619) 321-8733 or schedule a free consultation to review your specific situation. I also offer life insurance options that accept an ITIN. This page is general education, not individualized advice or a product recommendation.
Frequently asked questions
Why would I choose Plan K, L, or M instead of Plan G or Plan N?
Mainly the monthly premium. Plans K, L, and M usually cost less per month than Plan G or Plan N because they share a portion of costs with you instead of covering nearly everything. They're a reasonable option for someone who wants a lower premium, can handle some coinsurance, and for Plan K and L, values having an annual out-of-pocket limit that caps their risk.
What exactly is the out-of-pocket limit on Plans K and L?
It's a maximum dollar amount Medicare sets each year (higher for Plan K than Plan L, because Plan K shares more costs with you). Once your own out-of-pocket spending on Medicare-covered services reaches that limit within the calendar year, your K or L policy pays 100% of Medicare-covered costs for the rest of the year. Plan M and Plan D do not have this limit.
Does Plan M cover the Part A deductible the same way Plan D does?
No. That's the one real difference between Plan M and Plan D: Plan M covers only 50% of the Part A hospital deductible, while Plan D covers it at 100%. That's why Plan M usually carries a lower monthly premium than Plan D, in exchange for that one specific shared risk.
Do Plans K, L, and M cover the Part B deductible?
No. None of the three cover the annual Part B deductible; you pay it out of pocket yourself before Medicare and your Medigap policy's coverage kicks in for outpatient medical services.
Do Plans K, L, and M cover the Part B excess charge?
No. None of the three cover the extra charge some doctors can bill above Medicare's approved rate. Only Plan F (closed to new beneficiaries since 2020) and Plan G cover that charge.
Can I buy Plan K, L, or M if I've been Medicare-eligible for years already?
Yes, unlike Plan F, Plans K, L, and M have no eligibility cutoff date. You can buy them any time you meet Medigap's general enrollment requirements, subject to your state's medical underwriting rules if you're outside your guaranteed-issue period.
Are these plans common or easy to find?
Not as commonly as Plan G or Plan N. Many insurers offer few or no Plan K, L, or M policies in some states, so availability varies a lot by ZIP code. It's worth confirming which specific insurers sell them in your area before deciding one of these plans is right for you.