This chapter discusses the evaluation of health information technology (health IT) programs, focusing on the distinction between formative and summative evaluations, and presenting relevant theories and frameworks. Key components of program evaluation, methods for data collection, and theoretical perspectives that inform evaluations are elaborated to improve effectiveness and inform decision-making in clinical settings. The chapter emphasizes the unique challenges of health IT evaluations and aims to equip readers with the necessary knowledge to lead or participate in such evaluations.