Multisite Advancement of Research on Chronic Posttraumatic Headache

Inclusion Criteria: * Any veteran or active duty service member (DEERS-eligible; age 18 to 70 years) with mild or moderate TBI whose headache began or exacerbated within 3 months of a head or neck injury. * Headache meets ICHD-3 A5.2 criterion for delayed-onset persistent headache attributable to mild or moderate TBI and PTH is ongoing at enrollment (most recent headache within the past 2 weeks). * At least moderate to severe headache-related disability based on a HIT-6 score greater than 50. * Participant is stable on headache medication at baseline assessment (i.e., no changes in medication prescriptions in the past 4 weeks or study physician clinical judgement confirms stability; this includes botulinum toxin injections and devices like Cefaly). * Participant has a phone where they can receive reminders and complete the on-line Headache Diaries. * Participant speaks and reads/understands English well enough to fully participate in the intervention and to reliably complete assessment measures. Exclusion Criteria: * Participant reports a significant change in headache symptoms within 4 weeks of screening or has another secondary headache that may account for symptoms. * Participant has medication overuse headache based on Structured Diagnostic Headache Interview-Revised (Brief Version; SDIH-R) and clinical judgment. * Participant has a psychiatric problem that warrants immediate treatment as indicated in the electronic health record, flagged study during testing, or confirmed by a clinician through screening or review of clinical notes. * Participant demonstrates significant cognitive impairment that could impact treatment adherence/benefit.