This project proposes to use telemedicine-delivered cognitive-behavioral therapy (CBT) enhanced with continuous glucose monitor (CGM) review to target diabetes distress in adults with type 1 diabetes. The efficacy of CBT for diabetes distress (CBT-DD) will be tested in comparison to commercial FDA-approved CGM only in a randomized controlled clinical trial. The investigators' central hypothesis is that the addition of a CBT intervention that targets diabetes distress and self-management directly will yield clinically significant improvements in both diabetes distress and glycemic control relative to CGM alone. The investigators propose to recruit 93 adults (age 18-64) with type 1 diabetes from a national population for an entirely virtual 6-month study over four years, with targeted recruitment of racial/ethnic minorities. In addition to standard measurement of HbA1c for glycemic control and validated patient-reported outcome (PRO) surveys, the investigators plan to innovatively integrate momentary psychological and behavioral data via smartphone-based ecological momentary assessment with CGM data to assess day-to-day changes in diabetes distress, affect, self-management, and glycemia over the course of the trial.