Sleep Treatment Education Program-1 (STEP-1)

Inclusion Criteria: * Age 40-89 * History of a cancer diagnosis (except non-melanoma skin cancer) ≥ 1 year prior * No active cancer therapy (excluding chemoprevention) in the past four months, and no further therapy planned * Significant insomnia as evidenced by an Insomnia Severity Index score ≥12 * Regular access to the internet on a daily basis * Able to read and write in English Exclusion Criteria: * Survivors who report ever being diagnosed with Bipolar Disorder. * Survivors who report ever being diagnosed with a Seizure Disorder or have experienced a seizure in the past 12 months. * Intention to adjust (decrease or increase) use of any prescribed or over-the-counter medications taken to decrease insomnia during the study period. * Survivors diagnosed with sleep apnea who have declined treatment or are not adherent with treatment (as assessed by screening questions, see Appendix A). * Survivors with suspected sleep apnea who have not completed an evaluation by a sleep specialist (as assessed by screening questions, see Appendix A). * Usual bedtime does not fall between 5:00 pm and 5:00 am. * Employment that involves irregular sleep patterns, such as shift-work or frequent long-distance travel across time zones, or employment in a position that could impact public safety (such as air traffic-controller, operating heavy machinery) * Any impairment (e.g., hearing, visual, cognitive) that interferes with the ability to complete all study procedures independently. * Prior participation in a research study which provided an educational or behavioral intervention for insomnia. * Prior participation in a behavioral treatment or patient education program for insomnia delivered at the Dana-Farber Cancer Institute, or at Boston Children's Hospital. * Participation in behavioral or educational interventions for insomnia in the 2 years prior to enrollment. This includes in-person as well as synchronous and asynchronous online insomnia programs, but not independent use of books, workbooks or other written self-help materials addressing insomnia.