Medicare Supplement Plan K in Washington
Plan K pays half of most costs and caps what you can spend in a year at $8,000 (2026). The premium is among the lowest of any Medigap plan.
- Insurers selling it in WA
- 4
- Lowest monthly premium
- $103
- Lowest open to everyone 65+
- $121, Regence BlueShield
- Middle (median) premium
- $152
- Highest monthly premium
- $244
- Yearly gap, lowest to highest
- $1,692
How Plan K works
Plan K pays 100% of Part A hospital coinsurance and preventive care coinsurance. For most other gaps, including the Part A deductible, the 20% Part B coinsurance, skilled nursing and hospice, it pays 50% and you pay 50%. Once your out-of-pocket spending plus the Part B deductible reaches $8,000 in 2026, the plan pays 100% for the rest of the year.
It doesn't cover the Part B deductible, excess charges or foreign travel.
Plan K vs high-deductible Plan G
Both are low-premium plans. High-deductible Plan G has a lower worst case ($2,950 deductible in 2026) but you pay every dollar until you reach it. Plan K shares costs from the first claim but has a higher cap. For most people who want a low premium with a ceiling, high-deductible Plan G is the stronger design, if an insurer in your county sells it.
Who sells it in Washington
Only a few insurers, and three of them are regional Blue plans that split the state: Regence BlueShield in 22 western and central counties, Asuris Northwest Health in 16 eastern counties, and Regence BlueCross BlueShield of Oregon in Clark County. Between them and UnitedHealthcare (AARP), every Washington county has at least one Plan K option.
Plan K prices from Washington insurers
Medicare Supplement Plan K, monthly premium in Washington
Age 65+, monthly bank draft. Washington OIC chart current as of October 8, 2026.
| Insurer | Monthly | Yearly | Where it sells | Rate effective |
|---|---|---|---|---|
| UnitedHealthcare Insurance Company AARP membership required | $103 | $1,236 | All 39 counties | June 1, 2026 |
| Regence BlueShield | $121 | $1,452 | 22 counties | April 1, 2026 |
| Regence BlueCross BlueShield of Oregon | $182 | $2,184 | 1 counties | January 1, 2026 |
| Asuris Northwest Health | $244 | $2,928 | 16 counties | April 1, 2026 |
Not every insurer sells everywhere. Regence BlueShield sells this plan in 22 counties. Regence BlueCross BlueShield of Oregon sells this plan in 1 county. Asuris sells this plan in 16 counties. Check your county page for the list that applies to you.
What Plan K covers next to other plans
| Benefit | K | G | N | F |
|---|---|---|---|---|
| Part A hospital coinsurance, plus 365 extra hospital days after Medicare benefits end | 100% | 100% | 100% | 100% |
| Part A hospice care coinsurance or copay | 50% | 100% | 100% | 100% |
| Part B coinsurance or copay (the 20%) | 50% | 100% | 100%* | 100% |
| Medicare preventive care Part B coinsurance | 100% | 100% | 100% | 100% |
| First 3 pints of blood | 50% | 100% | 100% | 100% |
| Skilled nursing facility care coinsurance | 50% | 100% | 100% | 100% |
| Part A deductible | 50% | 100% | 100% | 100% |
| Part B deductible | – | – | – | 100% |
| Part B excess charges | – | 100% | – | 100% |
| Foreign travel emergency (up to plan limits) | – | 80% | 80% | 80% |
| Yearly out-of-pocket limit | $8,000 | – | – | – |
Common questions
What is the cheapest Plan K in Washington?
On the OIC chart current as of October 8, 2026, the lowest Plan K premium among the insurers we compare is $103 a month from UnitedHealthcare Insurance Company (AARP membership required).
Does my age change the Plan K premium in Washington?
No. Washington requires community rating, so an insurer charges every policyholder 65 and older the same premium for the same plan. Premiums can still rise for everyone when the insurer gets a rate increase approved.
How many insurers sell Plan K in Washington?
4 insurers have an approved Plan K premium on the current OIC chart. Some sell only in certain counties.