Medicare Advantage plans in Contra Costa, CA, 2027
Contra Costa, California has 5 Medicare Advantage plans open to everyone for 2027 (6 in 2026) and 5 special needs plans, according to the CMS landscape files; 2 of the open plans have a $0 premium. 2 plans that served the county in 2026 end or leave it, with 3,577 members living here in September 2026.
What changes in Contra Costa for 2027?
| In the county | 2026 | 2027 | Change |
|---|---|---|---|
| Plans open to everyone | 6 | 5 | ▼down 1 |
| Special needs plans | 5 | 5 | no change |
| Plans with a $0 premium | 2 | 2 | no change |
| Plans that lower the Part B premium | 2 | 2 | no change |
| Median out-of-pocket limit | $4,200 | $3,900 | ▼down $300 |
Source: CMS Medicare Advantage and Part D landscape files for 2027 (Sept. 22, 2026, revised Sept. 30) and 2026 (Sept. 2, 2026 revision); CMS plan benefit package files, 2027 and 2026.
Which plans can anyone in Contra Costa join?
| Plan | Premium | Out-of-pocket limit | Part B reduction | 2026 stars |
|---|---|---|---|---|
| Imperial Dynamic PlanH5496-012 · HMO | $0 | $295 | $15 | 3.5 of 5 |
| Imperial Courage PlanH5496-016 · HMO | $0 | $2,999 | $85 | 3.5 of 5 |
| Kaiser Permanente Sr Adv Basic Contra CostaH0524-061 · HMO | $29 | $6,000 | none | 4.5 of 5 |
| HumanaChoiceH5525-084 · PPO | $93 | $6,750 | none | 3.5 of 5 |
| Kaiser Permanente Sr Adv Enhanced Contra CostaH0524-033 · HMO | $98 | $3,900 | none | 4.5 of 5 |
Source: CMS Medicare Advantage and Part D landscape files for 2027 (Sept. 22, 2026, revised Sept. 30) and 2026 (Sept. 2, 2026 revision); CMS plan benefit package files, 2027 and 2026. Stars are the contract's 2026 rating. confirm on Medicare Plan Finder.
Which plans leave Contra Costa in 2027?
Members of these plans here choose a 2027 plan during open enrollment, October 15 to December 7, 2026; choosing by December 31 means no gap; because their plan is leaving the county, they can still join until the end of February 2027, with coverage from the first of the next month. Each plan's page says what happens to its members.
| 2026 plan | Members here, Sept. 2026 | For 2027 |
|---|---|---|
| AARP Medicare Advantage from UHC CA-8H0543-189 | 3,413 | Not offered |
| Central Health Dual Access PlanH5649-024 | 164 | Not offered |
Source: CMS plan crosswalk from 2026 to 2027 (Oct. 1, 2026); CMS monthly enrollment by plan and by county, September 2026 (CMS hides counts under 11); CMS Medicare Advantage and Part D landscape files for 2027 (Sept. 22, 2026, revised Sept. 30) and 2026 (Sept. 2, 2026 revision).
Which special needs plans are sold here?
Open only to people with Medicaid as well as Medicare, with certain chronic conditions, or living in an institution.
| Plan | Who can join | Premium |
|---|---|---|
| Imperial Senior ValueH5496-005 | Chronic or Disabling Condition | $0 |
| UHC Complete Care Support CA-8APH0543-249 | Chronic or Disabling Condition | $0 |
| Kaiser Permanente Dual Complete North P17H8794-017 | Dual-Eligible | $0 |
| Imperial FlexH5496-017 | Chronic or Disabling Condition | $2.70 |
| Contra Costa Health Care PlusH5119-001 | Dual-Eligible | $7.30 |
Source: CMS Medicare Advantage and Part D landscape files for 2027 (Sept. 22, 2026, revised Sept. 30) and 2026 (Sept. 2, 2026 revision).
How many people in Contra Costa use Medicare Advantage?
120,283 of the county's 230,629 people with Medicare were in a Medicare Advantage plan in September 2026, 52.1%; in California as a whole the share is 51.5%.
Source: CMS Medicare Advantage state and county penetration, September 2026.
What else should you check?
- Medicare Advantage in CaliforniaEvery county of the state
- 10 stand-alone drug plans in CaliforniaIf you keep Original Medicare
- Is your plan ending?Every plan not offered in 2027