Health Care Service Corporation to acquire Trustmark Health Benefits Aug 12, 2022 | Insurance, Top Stories Health Care Service Corporation said Thursday it's acquiring Trustmark Health Benefits, a subsidiary of Lake Forest-based Trustco, for an undisclosed amount.To access this content, you must purchase 1 Year Health News Illinois Subscription or 1 Year Group Subscription - Up to 5 Users, or log in if you are a member.