Alameda & Contra Costa Counties Launch New D-SNP Plan December 17, 2024 Hot Topics Beginning January 1, 2026, the two Managed Care Plans (MCPs) in Alameda and Contra Costa Counties, Alameda Alliance for Health and Contra Costa Health Plan, will launch a new Medicare Advantage Dual Eligible Special Needs Plan (D-SNP). Your current patients who chose to join this new plan will become out of network, unless you choose to contract with the Alliance or Contra Costa Health Plan.