Health Care Service Corp. has completed previously announced plans to acquire MEDecision Inc. for about $121 million in cash

Health Care Service, Chicago, the parent of the Blue Cross and Blue Shield plans in Illinois, Texas and other states, first announced the deal in June.

MEDecision, Wayne, Pa., sells health care administration and health information management software.

The acquisition should strengthen the ability of Health Care Service to help plan customers cut their medical costs, Health Care Service says.