The purpose of this research study is to learn about how Shared Decision Making, when used to decide treatment, impacts treatment engagement, retention, and outcomes for active duty military personnel seeking treatment for posttraumatic stress disorder (PTSD). Shared Decision Making between the service member and the therapists will be used to match patients to 1 of 3 different types of therapy for PTSD: (1) Prolonged Exposure (PE) therapy, (2) Cognitive Processing Therapy (CPT), or (3) Written Exposure Therapy (WET) in 1 of 2 different frequencies: (1) massed (daily) or (2) spaced (weekly).