Medicare Advantage in Plymouth County, Massachusetts
42,499 people in Plymouth County, Massachusetts were enrolled in Medicare Advantage in October 2026, 31.8% of 133,629 eligible beneficiaries (−0.4 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 22% of reported enrollment; 16 parent organizations have 11 or more members and the HHI is 1,666 (moderately concentrated). For 2027, 6,913 members here are in plans that terminate or leave the county. MA plans offered go from 37 to 34.
Parent organizations in Plymouth County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 9,343 | −1,419 | 22.1% |
| Point32Health, Inc. | 9,306 | −723 | 22.0% |
| Blue Cross and Blue Shield of Massachusetts, Inc. | 7,776 | −1,299 | 18.4% |
| CVS Health Corporation | 6,699 | +1,178 | 15.8% |
| Mass General Brigham Incorporated | 2,796 | +1,889 | 6.6% |
| CareSource | 2,692 | +84 | 6.4% |
| Molina Healthcare, Inc. | 1,270 | −63 | 3.0% |
| Fallon Community Health Plan, Inc. | 1,001 | +123 | 2.4% |
| Eternal Health of Delaware, Inc. | 954 | +757 | 2.3% |
| Elevance Health, Inc. | 164 | +10 | 0.4% |
| Humana Inc. | 132 | +70 | 0.3% |
| Harbor Health Services, Inc. | 97 | +2 | 0.2% |
| Blue Cross & Blue Shield of Rhode Island | 17 | +1 | under 0.1% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 16 | −19 | under 0.1% |
| Highmark Health | 13 | new | under 0.1% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 38,291 beneficiaries in Plymouth County were assigned to 142 Medicare Shared Savings Program ACOs, 57.2% of assignable Original Medicare beneficiaries. Together, roughly 71% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.