Store-and-forward telepsychiatry, or asynchronous telepsychiatry (ATP), which allows clinical data, including video to be collected to be reviewed at a later time by a specialist, has been described as a feasible alternative to real-time telepsychiatry, or synchronous telepsychiatry (STP), as a consultation model for primary care. In theory, ATP should be economically more cost-effective than STP due to the increased flexibility of patient data collection and the substitution of the time of specialists with that of lower-cost providers. The aim of this study was to conduct a retrospective cost-analysis comparing ATP with STP and traditional in-person psychiatric consultations in the primary care setting. One hundred and twenty five ATP consultations were performed and fixed and marginal costs were calculated for each model using inputs such as equipment costs, time spent by providers and support staff, and hourly salaries. The fixed costs were $7,000 and $20,000 for ATP and STP and marginal costs were $68.18, $107.50, and $96.36, respectively, for the three groups. STP was the most expensive of the three types of consultations. ATP became the most cost-effective of the three models beyond 249 consultations. The marginal cost savings of ATP were due to substitution of low-cost providers for specialists. ATP represents a potential disruptive healthcare process that could allow more affordable care to be delivered to a larger population of patients. A full accounting of ATP's efficiency will require further studies, including prospective cost-benefit analyses from the perspectives of the patient, provider, and society.