WASHINGTON--(BUSINESS WIRE)--Jan. 12, 2005--The Center for Health Transformation today announced that MedImpact Health Systems, Inc., the nation's largest privately held pharmacy benefit management (PBM) company, has joined the Center as a Founding Charter Member. The Center for Health Transformation was created nearly two years ago by individuals, organizations, policymakers and corporations who are united in their efforts to pursue and advocate for a transformed system of health for the 21st Century.