Medicare Advantage plans in San Mateo, CA, 2027
San Mateo, California has 18 Medicare Advantage plans open to everyone for 2027 (22 in 2026) and 8 special needs plans, according to the CMS landscape files; 11 of the open plans have a $0 premium. 9 plans that served the county in 2026 end or leave it, with 2,212 members living here in September 2026.
What changes in San Mateo for 2027?
| In the county | 2026 | 2027 | Change |
|---|---|---|---|
| Plans open to everyone | 22 | 18 | ▼down 4 |
| Special needs plans | 11 | 8 | ▼down 3 |
| Plans with a $0 premium | 15 | 11 | ▼down 4 |
| Plans that lower the Part B premium | 4 | 3 | ▼down 1 |
| Median out-of-pocket limit | $3,550 | $3,550 | no change |
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 San Mateo join?
| Plan | Premium | Out-of-pocket limit | Part B reduction | 2026 stars |
|---|---|---|---|---|
| Imperial Dynamic PlanH5496-012 · HMO | $0 | $295 | $15 | 3.5 of 5 |
| Anthem PrimeH4161-005 · HMO-POS | $0 | $1,200 | none | 3 of 5 |
| SCAN ClassicH5425-075 · HMO | $0 | $2,000 | none | 4 of 5 |
| SCAN Costco Medicare AdvantageH5425-139 · HMO | $0 | $2,000 | none | 4 of 5 |
| SCAN AlliedH5425-118 · HMO | $0 | $2,900 | none | 4 of 5 |
| Imperial Courage PlanH5496-016 · HMO | $0 | $2,999 | $85 | 3.5 of 5 |
| Central Health Harmony 031H3815-031 · HMO | $0 | $3,400 | none | 4 of 5 |
| CCHP Senior Value ProgramH0571-007 · HMO | $0 | $3,500 | none | 3 of 5 |
| Aetna Medicare Signature ExtraH0523-070 · HMO | $0 | $3,600 | none | 3 of 5 |
| Aetna Medicare EagleH0523-099 · HMO | $0 | $4,450 | $40 | 3 of 5 |
| Anthem Medicare AdvantageH0544-096 · HMO-POS | $0 | $5,600 | none | 3 of 5 |
| Alignment Health Honor Plus 060H3815-060 · HMO | $7.30 | $9,850 | none | 4 of 5 |
| Kaiser Permanente Senior Advantage Basic San MateoH0524-065 · HMO | $28 | $6,000 | none | 4.5 of 5 |
| CCHP Senior ProgramH0571-001 · HMO | $38 | $3,000 | none | 3 of 5 |
| Sutter Senior Advantage, a SCAN Medicare PlanH5425-148 · HMO | $49 | $4,900 | none | 4 of 5 |
| Alignment Health Sutter Advantage +MoreH3815-023 · HMO | $50 | $4,900 | none | 4 of 5 |
| Blue Shield InspireH0504-041 · HMO | $60 | $4,300 | none | 4 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 San Mateo 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 My ChoiceH4961-003 | 1,010 | Not offered |
| Central Health Classic Care Plan IVH5649-018 | 721 | Not offered |
| Central Health Embrace Care PlanH5649-025 | 250 | Not offered |
| Aetna Medicare EagleH5521-369 | 91 | Not offered |
| Aetna Medicare EnhancedH5521-676 | 84 | Not offered |
| Central Health Embrace Choice PlanH5649-026 | 41 | Not offered |
| Central Health Valor Care PlanH5649-030 | 15 | Not offered |
| Advantage CareH3274-005 | fewer than 11 | Leaves the county |
| Central Health Dual Access PlanH5649-024 | fewer than 11 | 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 |
| Premier CareH3274-002 | Institutional | $0 |
| SCAN BalanceH5425-076 | Chronic or Disabling Condition | $0 |
| SCAN StriveH5425-098 | Chronic or Disabling Condition | $0 |
| Kaiser Permanente Dual Complete North P22H8794-022 | Dual-Eligible | $0 |
| Imperial FlexH5496-017 | Chronic or Disabling Condition | $2.70 |
| Senior CareH3274-001 | Institutional | $7.30 |
| CareAdvantageH6019-001 | 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 San Mateo use Medicare Advantage?
73,635 of the county's 145,424 people with Medicare were in a Medicare Advantage plan in September 2026, 50.6%; 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