Abstract: Background: Annually, thousands of Veterans file Department of Veterans Affairs' (VA) disability claims (“service connection”) for posttraumatic stress disorder (PTSD) related to military sexual trauma (MST). Service connection provides free covered healthcare and compensation. To qualify, Veterans must meet PTSD diagnostic criteria, have sufficient evidence of the MST, and establish a link between their PTSD symptoms and MST. Methods: Among VA-enrolled Veterans who filed for MST-related PTSD service connection between 2017 and 2022 (N = 19,509), we modeled the probability of denied PTSD service connection as a function of MST type (i.e., assault versus harassment) and any instance of a psychiatric diagnosis in the VA electronic health record prior to PTSD claim decision, while controlling for demographics, PTSD diagnosis, and VA MST screen. Results: Veterans with sexual harassment claims had 2.86 times (d = 0.37) higher odds of being denied (42.7 %) compared to those with sexual assault claims (20.7 %). Diagnoses of personality disorders, anxiety disorders, substance use disorders, bipolar disorders, and schizophrenia spectrum disorders were associated with increased odds of PTSD claims being denied (OR = 1.20–2.01). Limitations While the full population of Veterans filing MST claims during this timeframe, the sample included relatively few harassment-only claims and was limited to demographic information in VA records, possibly resulting in overlooked confounders or determinants. Conclusion: Skilled claims assistance and equitable evidentiary requirements for MST-related PTSD claims compared to PTSD claims not related to MST, and for any trauma claims for a non-PTSD diagnosis (e.g., anxiety or depression) may reduce disparities in service connection.