Insomnia is commonly reported by military populations, especially those with comorbid mental and physical health conditions. Co-occurring conditions result in an altered presentation of insomnia symptoms, and complicate provision of cognitive-behavioral therapy for insomnia (CBT-I), requiring supplementary assessment or modifications to traditional techniques. CBT-I has consistently demonstrated positive outcomes for active-duty service members and veterans, even in the context of significant comorbidities such as post-traumatic stress disorder, depression, sleep apnea, and chronic pain. Despite its promise, studies of CBT-I in some populations, including women and individuals with substance use disorders, remain relatively understudied in active-duty and veteran populations.