Medicare Advantage plans in Marin, CA, 2027
Marin, California has 11 Medicare Advantage plans open to everyone for 2027 (12 in 2026) and 12 special needs plans, according to the CMS landscape files; 7 of the open plans have a $0 premium. 2 plans that served the county in 2026 end or leave it, with 54 members living here in September 2026.
What changes in Marin for 2027?
| In the county | 2026 | 2027 | Change |
|---|---|---|---|
| Plans open to everyone | 12 | 11 | ▼down 1 |
| Special needs plans | 11 | 12 | ▲up 1 |
| Plans with a $0 premium | 9 | 7 | ▼down 2 |
| Plans that lower the Part B premium | 4 | 3 | ▼down 1 |
| Median out-of-pocket limit | $3,349.50 | $3,650 | ▲up $300.50 |
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 Marin join?
| Plan | Premium | Out-of-pocket limit | Part B reduction | 2026 stars |
|---|---|---|---|---|
| Imperial Dynamic PlanH5496-012 · HMO | $0 | $295 | $15 | 3.5 of 5 |
| Alignment Health Platinum + Instacart 016H3815-016 · HMO-POS | $0 | $1,100 | none | 4 of 5 |
| Anthem PrimeH4161-005 · HMO-POS | $0 | $1,200 | none | 3 of 5 |
| Imperial Courage PlanH5496-016 · HMO | $0 | $2,999 | $85 | 3.5 of 5 |
| Alignment Health My Choice 050H3815-050 · HMO | $0 | $3,499 | none | 4 of 5 |
| Humana Gold PlusH5619-147 · HMO | $0 | $3,650 | none | 3 of 5 |
| Humana USAA Honor GivebackH5525-079 · PPO | $0 | $6,500 | $75 | 3.5 of 5 |
| Alignment Health Honor Plus 060H3815-060 · HMO | $7.30 | $9,850 | none | 4 of 5 |
| Kaiser Permanente Senior Advantage Basic MarinH0524-064 · HMO | $27 | $6,000 | none | 4.5 of 5 |
| HumanaChoiceH5525-087 · PPO | $96 | $7,150 | none | 3.5 of 5 |
| Kaiser Permanente Sr Adv Enhanced Marin San MateoH0524-031 · HMO | $97 | $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 Marin 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 |
|---|---|---|
| Alignment Health Honor+ PlanH3815-052 | 54 | Leaves the county |
| Advantage CareH3274-005 | fewer than 11 | Leaves the county |
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 |
| Premier CareH3274-002 | Institutional | $0 |
| Alignment Health Heart & Diabetes 010H3815-010 | Chronic or Disabling Condition | $0 |
| Alignment Health Heart & Diabetes 048H3815-048 | Chronic or Disabling Condition | $0 |
| Alignment Health BreathEasy Plus 041H3815-041 | Chronic or Disabling Condition | $0 |
| Kaiser Permanente Dual Complete North P25H8794-025 | Dual-Eligible | $0 |
| Alignment Health Heart & Diabetes 051H3815-051 | Chronic or Disabling Condition | $0.10 |
| Imperial FlexH5496-017 | Chronic or Disabling Condition | $2.70 |
| Senior CareH3274-001 | Institutional | $7.30 |
| Alignment Health Duals+ 030H3815-030 | Dual-Eligible | $7.30 |
| Alignment Health Heart & Diabetes Plus 039H3815-039 | Chronic or Disabling Condition | $7.30 |
| Alignment Health Clarity Plus 042H3815-042 | Chronic or Disabling Condition | $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 Marin use Medicare Advantage?
29,502 of the county's 65,177 people with Medicare were in a Medicare Advantage plan in September 2026, 45.3%; 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