To further advance our understanding of the efficacy of inventory-based premarital education programs, this study examined whether the effects of the PREPARE program varied by delivery format. Following participation in the program, engaged couples exhibited positive gains in knowledge, felt more confident in their relationship, engaged in more positive conflict management behaviors, and felt more satisfied with their relationship. No differences were found between participants who completed a series of conjoint sessions versus a 1-day group workshop. These findings highlight the robustness of premarital education and suggest group workshops can have similar effectiveness as the more prevalent conjoint sessions.