This project studies the efficacy of patient-facing and clinician-facing nudges in promoting the uptake of influenza vaccines. Clinical and technological stakeholders at the Geisinger Foundation will assess the feasibility of nudges and determine those to be used in the study. We will answer our research question via messaged-based, patient-facing nudges such as sending appointment-creation links to patients and informing high-risk patients of the risks of flu complications. We will also test the efficacy of alert-based, clinician-facing nudges such as informing clinicians when patients have scheduled a flu vaccine, informing clinicians of high-risk patients, and evaluating the efficacy of vaccine scheduling and administration in clinical settings. The proposed research methods will evaluate the role of nudges in increasing vaccine uptake and will explore the interplay of patient-facing and clinician-facing nudges in promoting uptake.