The present study examines older adult married couples’ friendship support and strain trajectories. Friendship is essential across the life course. However, most studies examining friendship within the context of long-term marriages have not examined how friendship quality develops over time and have not treated the dyad as the unit of analysis. Growth mixture modeling and 3,608 married couples across three waves of the Health and Retirement Study (HRS) were used. Support and strain trajectories were assessed separately and spouses were assessed together in each analysis. Analyses of Variance (ANOVAs) were used to examine whether well-being and demographic factors distinguished classes. Three classes of friendship support trajectories and two classes of friendship strain trajectories were identified. The support classes were characterized by husbands’ friendship support stability, with the Spouses’ High, Stable Support serving as the optimal support trajectory class. The strain classes were characterized by relatively low levels of strain, with the Spouses’ Low, Decreasing Strain class serving as the optimal strain trajectory class. Both support and strain trajectories were distinguished by demographic, social, and well-being factors. The results provide evidence for the gendered nature of friendship support and strain patterns, and contributes to knowledge regarding factors associated with distinct longitudinal friendship patterns among married older adults. The findings also have implications for programmatic efforts and interventions aimed to strengthen friendships.