Objective: Telemental health (TMH) is not well described for mental health service delivery during crises. Most child and adolescent psychiatry training programs have not integrated TMH into their curricula and are ill equipped to respond during crises to their patients' needs. In this study, we present the implementation of a home-based TMH (HB-TMH) service during the COVID-19 pandemic. Methods: We describe the technological, administrative, training, and clinical implementation components involved in transitioning a comprehensive outpatient child and adolescent psychiatry program to a HB-TMH virtual clinic. Results: The transition was accomplished in 6 weeks. Most in-clinic services were rapidly moved off campus to the home. Owing to challenges encountered with each implementation component, phone sessions bridged the transition from in-clinic to reliable virtual appointments. Within 3 weeks (March 20, 2020) of planning for HB-TMH, 67% of all appointments were conducted at home, and within 4 weeks (March 27, 2020), 90% were conducted at home. By week 6 (April 3, 2020), reliable HB-TMH appointments were implemented. Conclusions: The COVID-19 pandemic crisis created the opportunity to innovate a solution to disrupted care for our established patients and to create a resource for youth who developed problems during the crisis. Our department was experienced in providing TMH services that facilitated the transition to HB-TMH, yet still had to overcome known and unanticipated challenges. Our experience provides a roadmap for establishing a HB-TMH service with focus on rapid implementation. It also demonstrates a role for TMH during (rather than after) future crises when usual community resources are not available.