ABSTRACT Grandparents in the United States play increasingly significant familial and societal roles, yet an underexplored aspect of their experiences is how the relationship between grandparents and their adult child influences the development of grandparent-grandchild relationships. To address this gap, this study explores (a) the associations between family communication patterns and grandparent-grandchild relational maintenance behaviors, and (b) the extent trust in their adult child mediates those relationships. Data from grandparents (N = 380, Mage = 57.17, SD = 9.68) revealed higher conversation orientations were indirectly associated with increased use of assurances, conflict management, positivity, advice, and social networks with the grandchild through trust in the adult child, whereas higher conformity orientations were indirectly associated with decreased use of these behaviors with the grandchild through trust in the adult child. These findings point to the complex nature of intergenerational family relationships and how trust in the adult child influences grandparent-grandchild relationships.