Shelton is Mason County's seat and its only city of more than 10,000 people, with 10,450 residents per OFM's April 2026 estimate. Here's something that surprises people: the city is younger than the county around it. The Census Bureau's 2020–2024 survey puts about 1,500 Shelton residents at 65 or older, roughly 14%. For Mason County as a whole, the same survey says 24%. Do the subtraction and roughly 15,000 of the county's 16,468 older residents (same survey) live outside the city, in a county the state describes as running from the Olympic Mountains to Hood Canal and the Puget Sound inlets. Shelton is still where the county's only hospital is.
That makes Shelton the hub where people sort out Medicare problems, whether they live inside city limits or far outside them. If your Medicare Advantage plan is leaving after 2026, here is what to know, built around the places you'd actually use.
What happens if you ignore the letter
Let me start with the default, because it's the part people misunderstand. If you do nothing at all, Medicare does not leave you uninsured. On January 1, 2027 you land in Original Medicare: Part A for hospital stays, Part B for doctor visits. You can keep using Mason General Hospital and any other provider that accepts Medicare.
What you don't get by default:
- Drug coverage. The prescription benefit inside your old plan ends December 31, 2026. Original Medicare doesn't replace it. Every refill is out of pocket until a Part D plan takes over.
- A cap on medical bills. Original Medicare by itself has no yearly out-of-pocket maximum. A Medigap policy is one way to fill that hole if you go this route.
- Penalty protection. Let 63 or more days pass with no drug plan or equivalent coverage, and Medicare can add a late enrollment penalty to your Part D premium, generally for as long as you keep Part D. It's figured as 1% of the national base premium ($41.33 in 2027) times the number of full months you went without.
One exception. Members who receive Extra Help get placed in a stand-alone drug plan by CMS when their Medicare Advantage plan departs, unless they've already settled on 2027 drug coverage themselves. And if you qualify for Extra Help or Medicaid but somehow end up with no drug plan, Medicare's LI NET program gives temporary Part D coverage while it gets sorted out.
The calendar that actually matters
| When | What you can do | Starts |
|---|---|---|
| Through Dec 7, 2026 | Open enrollment: change to any plan | Jan 1, 2027 |
| Dec 8 – Dec 31, 2026 | Special enrollment for plan exits | Jan 1, 2027 |
| January 2027 | Special enrollment continues | Feb 1, 2027 |
| February 2027 | Last month of special enrollment | Mar 1, 2027 |
| Nov 1, 2026 – Mar 4, 2027 | Medigap without health questions (OIC: apply from Nov 1) | No earlier than Jan 1, 2027 |
Sources: CMS CY2027 enrollment guidance; WA OIC; RCW 48.66.055. Dates assume your plan ends December 31, 2026.
A wrinkle worth knowing: the spring window that runs to March 31 belongs to people holding a Medicare Advantage plan on New Year's Day. Default into Original Medicare and your cutoff for getting back into Medicare Advantage is February 28. Our Washington statewide guide spells out the rest, including Medigap plan letters by eligibility year.
Places in Shelton that matter for this
Mason General Hospital, 901 Mt View Drive, is a Critical Access Hospital and the one hospital Mason County has on the DOH and CMS rosters. If you look at a replacement Medicare Advantage plan, confirm Mason General and your Shelton clinic are in its 2027 network, then confirm any Olympia or Bremerton specialists separately.
Lewis-Mason-Thurston Area Agency on Aging has an office at 2008 Olympic Hwy N (phone 360-427-2225). It's the Community Living Connections contact for Mason County: in-home help, caregiver support, and pointers to programs like Medicare Savings Programs if premiums are a strain.
Mason Transit runs buses inside the county with no fare. Its customer service line is 360-427-5033 (or 800-374-3747), and Dial-A-Ride reservations are taken Monday through Saturday, 8 a.m. to 5 p.m. If your new doctor is in Olympia, Route 6 goes there for 50 cents one-way at the senior fare.
SHIBA counseling for Mason County is sponsored by Senior Services for South Sound, which is based in Olympia, not Shelton (360-586-6181, ext. 134). On October 26, 2026, OIC's listing for it read "Currently not accepting appointments. For assistance, call Medicare at 1-800-633-4227." The statewide SHIBA line, 800-562-6900 (weekdays 8:30 to 4:30), and 1-800-MEDICARE, open 24 hours a day, 7 days a week except some federal holidays, are the realistic first calls.
Why your neighbors may be on a different path
Mason County is one of the places where Original Medicare is the majority choice: 54.5% of the county's 20,064 Medicare enrollees used it in July 2026, versus 45.5% in Medicare Advantage and other health plans (CMS counts). CMS doesn't break that down for Shelton alone. But it means the friend telling you "just get a supplement" and the friend telling you "find another Advantage plan" are both describing something common here. Both can be right; the drug list and doctor list decide it.
Your own plan notice sets your dates, and federal Medicare rules plus Washington law set everything else on this page. Before anything is final, check it with 1-800-MEDICARE, SHIBA or a licensed agent.
Questions from Shelton
If I do nothing, can I still go to Mason General Hospital in January?
Why is Shelton's 65+ share lower than Mason County's?
Where in Shelton can I get help with aging services?
If I default to Original Medicare, does the spring Medicare Advantage window help me?
Sources
- WA OFM April 1, 2026 population
- U.S. Census Bureau ACS 2020-2024, table B09020
- CMS Medicare Monthly Enrollment, July 2026
- CMS Hospital General Information
- Medicare.gov: Part D costs, penalty and LI NET
- CMS CY2027 Enrollment and Disenrollment Guidance
- WA OIC: Medicare Advantage plan changing or leaving
- WA OIC: Find a local SHIBA office
- Mason Transit Authority: fares
- Washington Community Living Connections directory
