Military servicemembers face substantial challenges due to war-related trauma exposure, including posttraumatic stress disorder (PTSD). Individuals with deficits in inhibitory control (IC) may have an increased risk of developing PTSD due to a reduced ability to regulate their cognitive responses to and disengage from trauma-related stimuli. After Deployment, Adaptive Parenting Tools (ADAPT) is a mindfulness-infused parenting program for military families that has also been found to have crossover effects on parental mental health. The present study examined whether fathers’ IC at baseline affected their response to this emotional skills–focused intervention and further influenced their PTSD symptoms 1 year later. The sample included 282 male National Guard and Reserve (NG/R) service members who had recently been deployed to Iraq or Afghanistan. Fathers were randomly assigned to either the ADAPT program or a control condition, with IC measured at baseline and PTSD symptoms measured at baseline and 1-year follow-up. Intent-to-treat analyses revealed no significant main effect of the intervention on fathers’ PTSD symptoms. However, fathers’ IC moderated intervention effects on PTSD symptoms, f2 = 0.03. The intervention had more beneficial effects on reducing fathers’ PTSD symptoms for participants with low IC at baseline. These findings are consistent with compensatory effects in the risk moderation hypothesis, which suggests that prevention or intervention programs are more effective for high-risk subgroups.