Study Objectives: In a randomized controlled noninferiority trial, we compared face-to-face and telemedicine delivery (via the AASM Sleep (TM) platform) of cognitive-behavioral therapy (CBT) for insomnia for improving insomnia/sleep and daytime functioning at posttreatment and 3-month follow-up. A secondary objective compared the modalities on treatment credibility, satisfaction, and therapeutic alliance. Methods: A total of 65 adults with chronic insomnia (46 women, 47.2 +/- 16.3 years of age) were randomized to 6 sessions of CBT for insomnia delivered individually via AASM Sleep (TM) (n = 33, CBT-TM) or face-to-face (n = 32, CBT-F2F). Participants completed sleep diaries, the Insomnia Severity Index (ISI), and daytime functioning measures at pretreatment, posttreatment, and 3-month follow-up. Treatment credibility, satisfaction, and therapeutic alliance were compared between treatment modalities. The ISI was the primary noninferiority outcome. Results: Based on a noninferiority margin of four points on the ISI and, after adjusting for confounders, CBT-TM was noninferior to CBT-F2F at posttreatment (beta = 0.54, SE = 1.10, 95% CI = 1.64 to 2.72) and follow-up (beta = 0.34, SE = 1.10, 95% CI = 1.83 to 2.53). Daytime functioning measures, except the physical composite scale of the SF-12, were significantly improved at posttreatment and follow-up, with no difference between treatment formats. CBT-TM sessions were, on average, nearly 10 min shorter, yet participant ratings of therapeutic alliance were similar to CBT-F2F. Conclusions: Telemedicine delivery of CBT for insomnia is not inferior to face-to-face for insomnia severity and yields similar improvements on other sleep and daytime functioning outcomes. Further, telemedicine allows for more efficient treatment delivery while not compromising therapeutic alliance.