HealthOne Care System Inc. says 2 more members of its independent physician groups in Massachusetts will join Aetna Inc.’s network.

3 of its medical groups already contract with Aetna, according to HealthOne, Boston.

Harvard Vanguard Medical Associates and Dedham Medical Associates will become part of the Aetna network Jan. 1, joining Health One’s Granite Medical, Southboro Medical Group and South Shore Medical Center.

The 5 groups serve about 600,000 patients in Massachusetts.