Medicare Advantage in Monterey County, California
12,321 people in Monterey County, California were enrolled in Medicare Advantage in October 2026, 16.2% of 76,034 eligible beneficiaries (+1.0 pts since October 2025). Montage Health is the largest parent organization with 68% of reported enrollment; 10 parent organizations have 11 or more members and the HHI is 4,786 (highly concentrated). HRSA classifies the county as partly rural. For 2027, 30 members here are in plans that terminate or leave the county, and Kaiser Foundation Health Plan, Inc. leaves. MA plans offered go from 6 to 6.
Parent organizations in Monterey County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Montage Health | 8,286 | +347 | 67.9% |
| UnitedHealth Group, Inc. | 950 | −38 | 7.8% |
| Imperial Health Plan of California | 778 | +184 | 6.4% |
| Elevance Health, Inc. | 635 | +2 | 5.2% |
| SANTA CRUZ MONTEREY MERCED SAN BENITO MARIPOSA MAN | 527 | new | 4.3% |
| California Physicians' Service | 519 | +14 | 4.3% |
| CVS Health Corporation | 343 | −25 | 2.8% |
| Kaiser Foundation Health Plan, Inc. | 98 | −28 | 0.8% |
| Humana Inc. | 46 | +2 | 0.4% |
| Alignment Healthcare USA, LLC | 19 | −4 | 0.2% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 14,342 beneficiaries in Monterey County were assigned to 118 Medicare Shared Savings Program ACOs, 31.1% of assignable Original Medicare beneficiaries. Together, roughly 42% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.