Medigap Plan K vs Plan L: Cost-Sharing Plans Explained

What Are Medicare Supplement Plans K and L?

Medicare Supplement (Medigap) Plans K and L are two of the ten federally standardized Medigap plan letters, and they are the only two designed around a cost-sharing structure. Instead of paying nearly all of your Medicare gap costs like Plan G or Plan F, they pay a fixed percentage (50% for Plan K, 75% for Plan L) of certain expenses. In return, they charge lower monthly premiums and add something Original Medicare does not have on its own: a hard annual out-of-pocket maximum.

Once you meet that yearly cap and the Part B deductible ($283 in 2026), the plan pays 100% of Medicare-covered services for the rest of the calendar year. That combination of lower premiums and a capped downside is what makes them worth a serious look, especially if you are healthy. For a broader view of how these fit alongside the other lettered plans, see our full Medigap plan comparison.

Plans K and L are available in most states, though Massachusetts, Minnesota, and Wisconsin use their own non-standardized Medigap structures and do not sell K or L by those names. If you live in one of those states, our state-by-state Medigap guide explains how the equivalent cost-sharing options work.

What Plan K and Plan L Actually Cover

All standardized Medigap plans must cover the same list of benefits. What changes is how much of each benefit they cover. Plan K pays 50% of a defined set of shared costs, and Plan L pays 75% of that same set. Both plans pay 100% of Part A hospital coinsurance plus 365 additional hospital days after Medicare benefits are exhausted.

Here is the side-by-side breakdown for 2026:

The 2026 CMS-set out-of-pocket limits for Medigap Plans K and L are $8,000 and $4,000, respectively, and these increases are based on estimates of the United States Per Capita Costs of the Medicare program. That is up from $7,220 and $3,610 in 2025, roughly a 10.8% increase in your maximum annual exposure, so shoppers who used to rely on last year's numbers should recalibrate.

Neither plan covers the Part B deductible, Part B excess charges, or foreign travel emergency care. If you travel abroad often or live in a state where doctors can bill above Medicare-approved amounts, that trade-off matters. To see how excess charges work and which states ban them, our guide to gaps Medigap fills is a good starting point. If you want the foreign travel benefit added back in, our Medigap foreign travel emergency guide shows which plan letters include it.

How the out-of-pocket cap works

The out-of-pocket cap only counts what you pay toward Medicare-approved services that the plan cost-shares on. For Plans K and L, after you meet your out-of-pocket yearly limit and your yearly Part B deductible ($283 in 2026), the Medigap plan pays 100% of covered services for the rest of the calendar year. This is a feature Plans G and N do not have because they cover so much upfront that a cap is unnecessary.

Plan K vs Plan L: A Direct Comparison

The easiest way to think about Plan K vs Plan L is this: Plan L costs more per month, but you reach the "everything paid" point twice as fast if you have a bad health year.

Because Plan L pays a higher share of every cost-sharing item, it also protects you sooner. If you ended up with a hospital stay and a rough recovery, hitting a $4,000 cap on Plan L is much less painful than hitting an $8,000 cap on Plan K.

How Much Do Plan K and Plan L Cost in 2026?

Medigap premiums are not standardized. Each carrier sets its own rates based on your state, ZIP code, age, gender, tobacco use, and pricing method (community-rated, issue-age, or attained-age). But across the market, Plans K and L are consistently the two cheapest lettered plans on the shelf. For guidance on comparing quotes across carriers, our Medicare Supplement quotes guide walks through the full shopping process.

Typical 2026 monthly premium ranges (age 65, non-smoker):

National 2026 estimates vary by source. GetMedicareSolutions places Plan K's 2026 average around $77 per month, while MoneyGeek's 2026 analysis puts Plan K at about $110 per month at age 65, with the overall Medigap average at $189. Our 2026 Medicare Supplement cost guide shows the national average Plan G premium is around $166 at age 65 and Plan N averages about $123. Plan K commonly comes in $50 to $100 per month cheaper than Plan G in the same market. Over a full year, that is $600 to $1,200 in premium savings that you can reserve for potential cost-sharing.

State-level filings back this up. In Kansas, Blue Cross Blue Shield's Plan K base rate is about $85 per month and Plan L is about $125 per month, coming in $13 and $33 below state averages. In Missouri, Transamerica offers the lowest rates on Plan K at about $92 per month and Plan L at about $136. Maryland's 2026 rate guide shows Plan K premiums ranging from about $95 to $168 and Plan L ranging from about $136 to $244, depending on age and carrier. Some carriers post even lower entry-level rates, with Plan K premiums as low as $40 to $100 per month at age 65 in the least expensive markets.

Comparing K and L to Plan G and Plan N

Plan G is far more comprehensive: after the $283 Part B deductible, it pays essentially all Medicare cost-sharing. Plan N sits in the middle, with small copays for office visits and ER trips. For a full breakdown of Plan N's copay structure, see our Plan N deep dive, and for how Plan G stacks up, our Plan G coverage guide has the details. If low premiums are your priority but you want more predictable coverage than K or L offers, our High-Deductible Plan G analysis is worth reading too.

Which Carriers Still Sell Plan K and Plan L?

Not every Medigap carrier bothers with K and L because demand is thin. Many big-name insurers skip these letters entirely, focusing on G, HDG, and N where the volume is. Here are the major insurers still active in this space for 2026:

• AARP / UnitedHealthcare offers a broad Medigap lineup including Plans A, B, C, F, G, K, L, and N through group policies, making it the most consistently available source for Plan K and Plan L nationwide. See our full AARP Medicare Supplement review for pricing and rating details.
• Mutual of Omaha still lists Plans A, B, C, D, F, G, K, L, M, and N in its Medigap portfolio, though availability varies by state. Our Mutual of Omaha Medigap review covers current details.
• Humana sells Plan K and Plan L in select states, though national marketing typically emphasizes G, HDG, and N. Details on the lineup and discounts are in our Humana Medigap review.
• Blue Cross Blue Shield affiliates offer Plan K and Plan L in many states. In Kansas, for example, BCBS uses attained-age pricing on both plans and leads on cost-sharing plans, with Plan K at $85 and Plan L at $125 per month.
• Transamerica sells Plan K and Plan L in several states and is often among the lowest-priced carriers where it competes, including Missouri.
• United American Insurance Company is one of the few national carriers that consistently markets Plan K and Plan L across most states in 2026.
• Smaller regional insurers like Bankers Fidelity, Loyal American, Aetna, and Cigna/HealthSpring file K and/or L in specific states.

Who Should Actually Choose Plan K or Plan L?

Plans K and L are not for everyone. Most Medigap buyers pick predictability over savings. Plan G continued to be the most popular plan type in 2025, enrolling approximately 6.3 million members, and Plan F still held about 4.2 million. By contrast, Plan K held only about 0.72% of Medigap enrollment in the most recent industry report with 6,686 members, and Plan L held roughly 0.25% with 2,358 members. See our best Medicare Supplement plans guide for how these small-share plans still fit certain buyers.

Ideal candidates for Plan K or Plan L

• Healthy retirees who rarely see specialists and take few prescriptions
• Budget-conscious enrollees who want a Medigap plan but cannot stomach $180 or higher monthly premiums
• People with strong savings who could comfortably absorb the $4,000 or $8,000 cap in a bad year
• Seniors weighing Medigap vs. Medicare Advantage who want to stay in Original Medicare but keep premiums close to MA levels. Our Medigap vs. Medicare Advantage guide explains that trade-off in detail.
• Enrollees in states that ban Part B excess charges (CT, MA, MN, NY, OH, PA, RI, VT), where one of the biggest gaps in K and L is legally irrelevant

Who should skip K and L

If you have chronic conditions, take multiple medications, see specialists routinely, or simply want the peace of mind that comes with predictable bills, Plan G or Plan N is a better fit. Someone on the fence between Plan F and Plan G should read our Plan F explainer instead, especially if they were eligible for Medicare before January 1, 2020. Enrollees who want a lower-premium Medigap alternative with a hospital network should also consider Medicare SELECT plans.

Frequently Asked Questions

Is Medigap Plan K worth it in 2026?

Plan K can be worth it if you are healthy, want the lowest possible Medigap premium, and can comfortably absorb up to $8,000 in cost-sharing during a bad health year. The $8,000 annual out-of-pocket cap gives you catastrophic protection that Original Medicare alone does not offer. For low utilizers, the premium savings often outweigh the cost-sharing risk over multiple years.

What is the difference between Plan K and Plan L?

Plan K pays 50% of certain cost-sharing items with an $8,000 annual out-of-pocket cap in 2026, while Plan L pays 75% of those same items with a $4,000 cap. Plan L has higher monthly premiums but protects you sooner in a bad health year. Both plans cover 100% of Part A hospital coinsurance and add 365 extra hospital days.

Does Plan K or Plan L cover the Part B deductible?

No. Neither Plan K nor Plan L covers the Part B deductible, which is $283 in 2026. You must pay that deductible in full before the plan's out-of-pocket cap logic pays 100%. This is one of the main reasons these plans are cheaper than Plan G, which also does not cover the Part B deductible, or Plan F, which does but is closed to most new enrollees.

Are Plan K and Plan L available in every state?

Plans K and L are standardized Medigap plans in most states, but they are not sold under those letter names in Massachusetts, Minnesota, or Wisconsin, which have their own Medigap structures. Even in states where they are available, not every insurer offers them, so carrier options can be limited. Always check current availability in your ZIP code before enrolling.

Can I switch from Plan G to Plan K or Plan L later?

Yes, but you may face medical underwriting if you are outside your Medigap Open Enrollment Period or a guaranteed-issue window. That means the carrier can review your health history and either charge higher rates or deny coverage. A handful of states have "birthday rules" or year-round guaranteed-issue rights, so check your state's protections before assuming you can freely switch.