Fountain Valley-based MemorialCare Health System said today that its Seaside Health Plan is now open for business in Los Angeles County, with plans to expand into Orange County.

Seaside, a not-for-profit health plan, will offer customers a range of plans, including Medicare and Medi-Cal. MemorialCare said it will serve individuals and families who are members of partners such as Health Net Inc., Anthem Blue Cross and Blue Shield of California.

MemorialCare created Seaside after buying assets from Signal Hill-based Universal Care last November. It said that Seaside also will participate in a state demonstration project addressing the needs of children with certain diseases and chronic conditions.

MemorialCare owns Orange Coast Memorial Medical Center in Fountain Valley and Saddleback Memorial Medical Center, with campuses in Laguna Niguel and San Clemente.