This report presents final impact findings from a demonstration project and evaluation of Gender Matters (Gen.M), an innovative comprehensive sexuality education program that aims to reduce teen pregnancy and associated risk behaviors among U.S. adolescents, in part by challenging commonly held perceptions of gender roles and promoting healthy, equitable relationships. A long-standing body of research links adolescents’ gender role beliefs to their sexual and reproductive health outcomes. For both male and female adolescents, traditional attitudes toward gender roles have been correlated with a number of adverse sexual risk behaviors and outcomes, including early sexual initiation, unprotected sex, and teen pregnancy (Jewkes and Morrell 2010; Marcell et al. 2007; Marston and King 2006; Stewart 2003). Several international organizations, and a small number of U.S. organizations, have implemented gender transformative programs that create opportunities for youth to challenge gender norms, with a growing body of evidence demonstrating their effectiveness in improving sexual and reproductive health outcomes (DiClemente et al. 2004; Haberland 2015; Rottach et al. 2009). Despite compelling evidence on the importance of gender in youth risk reduction, Gen.M is one of the few teen pregnancy programs in the U.S. that explicitly address gender norms and dynamics related to adolescent sexual risk behaviors.