Research is increasing on the use of asynchronous technologies like e-mail, text, e-consultation, and asynchronous telepsychiatry by primary care and specialist clinicians. Clinicians need measurable skills, knowledge, and attitudes for these technologies to ensure quality care outcomes. This narrative review used a literature search of Medline, American Psychological Association PsycNET, PsycINFO, Embase, Cochrane, and Web of Science, using subject headings and keywords along with a manual search of reference lists of articles published by December 2019. Articles were included if they discussed and compared asynchronous technologies (e.g., asynchronous telepsychiatry), synchronous telepsychiatric (video including telemental and telebehavioral health), and in-person care. The review compares approaches, effectiveness, skills, and outcomes of these three modes of service delivery in behavioral health and primary care, since those clinicians interface with these technologies. Few studies have evaluated the efficacy and effectiveness of asynchronous technologies in behavioral, or compared them directly to synchronous and in-person care. Publications comparing synchronous telepsychiatry, asynchronous telepsychiatry, and other asynchronous technologies to in-person care focus on the technology used, how to do it, workflow processes, and medico-legal issues, but there is less written about clinical issues like the therapeutic frame, communication, boundaries, and trust. No studies specifically discuss behaviors or competencies for asynchronous care, though telepsychiatric, telebehavioral health, social media, and mobile health competencies have relevant elements. Users of asynchronous technologies (i.e., patients, primary care teams, and psychiatrists) need to adjust clinical skills, work as team members, and integrate technological and administrative factors into workflow. Implications for clinicians, trainees, faculty, administrators, and institutions are discussed. Asynchronous technologies improve access, reduce costs, and compliment other care options. Health systems must appraise how to help individuals and interprofessional participants best interface with a wide range of technologies. This requires adjustments in clinical and administrative workflow. Research in measurable competency sets, implementation, and outcomes is needed.