Referral model based on subject matter expert interviews. We identified three shared stages of the referral process based on the sequence and purpose of events and tasks: 1) submission of referral request by PCP; 2) referral review by the subspecialist; and 3) patient transition into subspecialty care. Referral requests are initiated using the EHR's order-entry interface (Figure 1). Upon receipt, subspecialists review requests to determine appropriateness, urgency and completeness, a process that could require additional information retrieval from the EHR. Subsequently, the referral is either: a) accepted and routed within the service to have an appointment scheduled; b) discontinued; or, c) deferred for further discussion with additional team members. Acceptance triggers a series of steps to coordinate patient transition into the subspecialty setting, including communication with patients to schedule appointments, followed by appointment reminders, an initial subspecialty encounter, and finally, communication of care plan back to the PCP through appropriate documentation of the referral encounter in the EHR.