Columbia County, WA Medicare Plan Ending Dec 31, 2026

In all of Columbia County, CMS counted 312 people in Medicare Advantage and other health plans in July 2026. That's it. Out of 1,356 people with Medicare, more than three in four use Original Medicare. So if you are one of the 312 and your plan has written to say it's done after December 31, 2026, this page is for you.

A small county with an older population

Columbia County	Count	Share
Residents, April 1, 2026 (OFM)	3,925
Residents 65 and older, April 1, 2025 (OFM)	1,259	31.9% of 3,950
People with Medicare, July 2026 (CMS)	1,356
Original Medicare	1,044	77.0%
Medicare Advantage and other health plans	312	23.0%
Stand-alone Part D drug plans	728
Part D inside a Medicare Advantage plan	284
Medicare and Apple Health (dual eligible)	222	16.4%
On Medicare because of a disability	126	9.3%

Sources: WA OFM population estimates; CMS Medicare Monthly Enrollment, July 2026 (people, not plans). Shares computed.

Nearly a third of the county is 65 or older, so Medicare is everyday business here. But private plans are unusual: Washington as a whole is roughly half and half, and Columbia County sits at about 23%. The 284 people whose drug coverage sits inside one of those plans are the ones with the most to sort out, because that coverage ends with the plan.

One hospital, and the road to Walla Walla

Dayton General Hospital, on South 3rd Street in Dayton, is the only hospital in the county in state DOH data. CMS lists it as a critical access hospital, the federal category for small rural hospitals. If your specialists are in Walla Walla or farther away, those offices belong in the picture too.

That shapes the choice in front of you:

Another Medicare Advantage plan works only as well as its network. Ask by name whether Dayton General, your doctor and any Walla Walla providers you use are in it for 2027. The county also borders Umatilla and Wallowa counties in Oregon; if you get any care across the state line, ask about that too.
Original Medicare has no network at all. A provider that accepts Medicare can bill it whether the office is in Dayton, Pendleton or anywhere else in the U.S.

Neither choice is automatically right. Original Medicare alone has no yearly cap on your costs, which is one reason some people add a supplement; drug coverage needs a separate Part D plan.

The rule that matters most here: Medigap without health questions

Medicare Supplement insurance, usually called Medigap, picks up some or all of the cost-sharing that Original Medicare doesn't. Outside certain windows, insurers are generally allowed to screen applicants on health. A plan ending opens one of those windows.

Under RCW 48.66.055 and the matching federal law, if your Medicare Advantage plan leaves your area and you move to Original Medicare, insurers must sell you certain Medigap plans. They can't turn you down, refuse to cover a pre-existing condition, or charge more because of your health. Which plans depends on when you were first eligible for Medicare:

First eligible for Medicare before 2020: anything from A to F (counting high-deductible F), plus K or L.
First eligible on or after January 1, 2020: A, B, D or G (counting high-deductible G), plus K or L.

Timing: the right starts the day your plan's notice reaches you and expires March 4, 2027, which is 63 days past the plan's last day. OIC asks people to apply on or after November 1. Apply in November or December and the policy can begin January 1. Send a copy of the plan's letter and keep the postmarked envelope. Choosing a different Medicare Advantage plan means passing on this right.

If you're among the 126 people on Medicare because of a disability, be careful. CMS's Medigap guide leaves Washington off its list of states with an under-65 requirement, and insurers only have to offer what they already sell to new customers. Call SHIBA before you rely on getting a supplement.

Drug coverage and the dates

Your current plan pays through December 31. Settle on 2027 coverage before the year is out and it's in place January 1 with nothing missing. Without a choice, you default to Original Medicare on New Year's Day, but with no drug coverage, unless you get Extra Help (CMS reassigns Extra Help enrollees to a stand-alone drug plan).

You do get extra time: a special enrollment window for people in departing plans opens December 8, 2026 and closes February 28, 2027. January enrollments take effect February 1; February enrollments, March 1. Past that, a stretch of 63 days or more without creditable drug coverage can mean a Part D late penalty that stays attached to your drug premium for as long as you have Medicare drug coverage. The full rules are in our statewide guide.

Getting to a new doctor: CCPT

Columbia County Public Transportation runs reservation-based, demand-response service and says it is fare free until June 30, 2027. It picks most riders up at home inside the county; outside the county it serves public building locations, not homes. Out-of-town buses run weekdays 5 a.m. to 6 p.m., and CCPT can drop riders at the Valley Transit Transfer Center at Main and 4th in Walla Walla to connect to local buses there. Call 509-382-1647 to book.

Apple Health members can also arrange non-emergency medical rides for Columbia County through People For People, 1-800-233-1624, with two business days' notice for local trips.

Who to call

Community Living Connections in Dayton: Southeast Washington Aging and Long Term Care lists a contact at 410 East Main, Dayton, 509-382-4787.
SHIBA: OIC lists Catholic Charities Serving Central Washington, based in Richland, as Columbia County's sponsor. Its listing said on October 26, 2026: "Currently not accepting appointments. For assistance, call Medicare at 1-800-633-4227." Use the statewide SHIBA line, 800-562-6900, during weekday business hours (8:30 to 4:30).
1-800-MEDICARE (1-800-633-4227), any time except some federal holidays, or compare plans yourself on Medicare Plan Finder.
Help with costs: Washington's Medicare Savings Programs pay Medicare premiums for people with limited income, with no asset test. Getting one also makes you eligible for Extra Help.

In the end, federal Medicare rules and Washington statute decide this, and the notice from your plan fixes your dates; double-check with 1-800-MEDICARE, SHIBA or a licensed agent before you change anything.

Columbia County answers

How many people in Columbia County are in Medicare Advantage and other health plans?

CMS counted 312 people in Medicare Advantage and other health plans in July 2026, about 23% of the 1,356 Columbia County residents with Medicare. The other 1,044 were in Original Medicare.

Can I see Walla Walla or Oregon doctors after my plan ends?

With Original Medicare, yes, at any provider that accepts Medicare. With another Medicare Advantage plan, it depends on that plan's 2027 network, so ask about each provider by name.

Can I buy a supplement in Columbia County without medical underwriting?

Yes, if your Medicare Advantage plan is ending and you move to Original Medicare. Washington law requires insurers to sell certain Medigap plans until March 4, 2027 for a plan ending December 31, 2026. OIC suggests applying on or after November 1.

Is there transportation from Dayton to Walla Walla?

Columbia County Public Transportation runs out-of-town trips on weekdays from 5 a.m. to 6 p.m. and can drop riders at the Valley Transit Transfer Center in Walla Walla. It says service is fare free until June 30, 2027. Call 509-382-1647.

Your Medicare plan is ending in Columbia County. You have more options than it may seem.