This study utilizes a stress process framework in conjunction with a crossover perspective to conceptualize how stress, specifically military-related stress, manifests within individuals and couples. An actor–partner interdependence mediation modeling approach was used in a cross-sectional sample of 243 military couples to examine whether difficulties managing military-related stress may erode one's own self-efficacy and, in turn, contribute to greater anxiety (actor effects) and/or one's partner's self-efficacy and, in turn, anxiety (partner effects). Further, the potential moderating impact of marital quality was explicated in the model to understand if greater marital quality might buffer the impact of military-related stress. There was support for the stress process model primarily regarding actor effects; fewer partner effects emerged. One's own perceptions of military-related stress, specifically higher stress, were related to lower levels of their own self-efficacy, and, consequently, higher anxiety, but military-related stress did not directly affect the partner's self-efficacy or anxiety. Both service members' and civilian spouses' marital quality had ramifications for civilian spouses' self-efficacy, specifically a buffering effect; that was not the case regarding civilian spouse effects on the military member. Findings point to specific ways in which military stressors have implications for personal well-being, the role of a strong couple relationship in buffering stress, especially for civilian spouses, and concomitant leverage points for supporting both individual and couple well-being.