Behavioral Insomnia Treatment in Mild Traumatic Brain Injury

Inclusion Criteria: * Active duty U.S. military service members. * At least 18 years of age. * Ability to provide informed consent and follow study-related instructions. * Self-report of a Mild Traumatic Brain Injury (mTBI) at least 3 months prior to enrollment based on self-report. * At least 2 postconcussive symptoms scored \> 2 (moderate) on the Neurobehavioral Symptom Inventory (NSI), with at least 1 of these symptoms from the cognitive domain in addition to the sleep disturbances item. * Clinically significant chronic insomnia disorder assessed by an independent evaluator using the Structured Clinical Interview for Sleep Disorders-Revised (SCISD-R)\_No Split Week Self-Assessment of Sleep Survey (SASS-Y). * Minimum score of 15 on the Insomnia Severity Index (ISI). * Plans to be in the area for the next 3 months. * Stable on psychotropic and hypnotic medications for at least 1 month. * Stable on continuous positive airway pressure therapy if diagnosed with sleep apnea for at least 1 month. Exclusion Criteria: * Moderate TBI (e.g., skull fracture, brain hemorrhage, hematoma) indicated by self-report or medical record. * Any sleep, medical, or psychiatric disorder requiring urgent treatment (e.g., suicide risk, substance use, insomnia with occupational impairment in high risk professions; very short sleep duration of less than 4 hours on average; bipolar disorder or psychosis) or that otherwise interferes with the completion of the baseline assessment. * Working night shifts (i.e., duty later than 9:00 pm or before 5:30 am) more than 3 times per month. * Planned major surgery. * Pregnancy, assessed by self-report and review of medical record.