Inclusion Criteria:  One member of the couple be a Veteran enrolled in the San Diego VA Healthcare System with a Posttraumatic Stress Disorder Checklist-5 score of > 33, indicating a likely PTSD diagnosis. Agree not to receive other individual or conjoint psychotherapy for PTSD during the treatment portion of the study If already on psychoactive medication prior to study referral, Veteran participant must remain on a stable psychoactive medication regimen for at least 45 days.  Exclusion Criteria:  Acute suicidality Psychosis Active substance use disorder Severe ongoing medical problems, including heart disease and neuroendocrinological disorders (e.g., diabetes) Uncontrolled hypotension (systolic blood pressure <100 mm Hg) or hypertension (>160/100 mm Hg) Pregnancy, delivery in the past 6 months, or current breastfeeding Severe intimate aggression reported by either partner