A subsidiary of Philadelphia-based AmeriHealth Caritas was one of four companies selected by Iowa officials to participate in the management of the state's $4.2 billion Medicaid program, which serves about 560,000, officials announced Tuesday.

AmeriHealth and the other winners - units of Anthem Inc., UnitedHealth Group Inc., and WellCare Health Plans Inc. - will compete statewide for Medicaid beneficiaries under the program, which starts Jan. 1, 2016.

Iowa officials picked four of 10 health insurer applicants that completed the process.

Among those not selected were units of Centene Corp. and Molina Healthcare Inc., two Medicaid managed care companies that are significantly bigger than AmeriHealth Caritas, which ranked No. 7 in the nation in January, according to Decision Resources Group.