The Health Maintenance Organization Research Network (HMORN), a consortium of 16 health care delivery systems with integrated research divisions, held its annual meeting in Danville, Pennsylvania in April of 2009 and was attended by more than 260 researchers and operational leaders from HMORN organizations, pharmaceutical companies, the National Cancer Institute, and the Agency for Healthcare Research and Quality. The 2009 meeting was held from April 26(th) to April 29(th) at the Henry Hood Center for Health Research, and was hosted by Geisinger Health System. The conference theme was "Clinical Effectiveness: Leadership in Comparative Effectiveness and Translational Research." This article provides some background on the network, its research activities, and the annual conference. This issue of Clinical Medicine & Research also includes selected scientific abstracts presented at the meeting.