Medicare Advantage in Nassau County, New York
102,443 people in Nassau County, New York were enrolled in Medicare Advantage in October 2026, 33.5% of 306,191 eligible beneficiaries (+0.4 pts since October 2025). CVS Health Corporation is the largest parent organization with 33% of reported enrollment; 16 parent organizations have 11 or more members and the HHI is 1,926 (highly concentrated). For 2027, 16,717 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 31 to 28.
Parent organizations in Nassau County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| CVS Health Corporation | 33,502 | +7,538 | 32.8% |
| Healthfirst, Inc. | 20,671 | +2,664 | 20.2% |
| UnitedHealth Group, Inc. | 16,296 | −3,318 | 16.0% |
| Humana Inc. | 7,620 | +1,555 | 7.5% |
| Elevance Health, Inc. | 7,222 | +353 | 7.1% |
| Centene Corporation | 7,079 | −581 | 6.9% |
| EmblemHealth, Inc. | 5,091 | −140 | 5.0% |
| Visiting Nurse Service of New York | 2,222 | +1,131 | 2.2% |
| Elderplan, Inc. | 1,023 | +344 | 1.0% |
| Health Care Service Corporation | 779 | −5,809 | 0.8% |
| CenterLight Health System, Inc. | 178 | +23 | 0.2% |
| Hamaspik of Rockland County, Inc. | 139 | +44 | 0.1% |
| NY Hotel Trades Council&Hotel Assn of NYC | 128 | −7 | 0.1% |
| Molina Healthcare, Inc. | 76 | +31 | under 0.1% |
| Village Care of New York, Inc. | 73 | +34 | 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, 37,094 beneficiaries in Nassau County were assigned to 206 Medicare Shared Savings Program ACOs, 24.3% of assignable Original Medicare beneficiaries. Together, roughly 50% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.