Autism spectrum disorder (ASD) is a pervasive and often difficult health condition, the consequences of which ripple through family relationships. This paper engages relational turbulence theory, which addresses communication in romantic relationships, and the experiencing life transitions model, from the field of nursing, to examine how communication between parents affects the marital relationship during a major transition in the life of a child with ASD. Transition processing communication (TPC) includes four forms of communication that can help married partners navigate difficult life events: increasing interaction, promoting connection, promoting feeling situated, and increasing confidence in the relationship. This study examines the effects of partners' TPC on their own and their spouse's experiences of relational uncertainty, changes in interdependence, and relational turbulence. A total of 33 couples and 60 married, female individuals, parents of a child with ASD who was starting school for the first time, completed a pre-test, 14 dairies, and a post-test; diaries were completed every three days over a 42-day period, beginning on the child's first day of school. Findings suggest that partners' engagement in TPC significantly affects some relationship qualities. In addition, an individual's perceptions of his or her spouse's communication were a stronger predictor of relational turbulence than the spouse's self-reported communication. Results point to several implications for understanding the ways in which married partners can protect their marriage in the face of their child's health-related transitions.