Scholars have long documented the intersection between social identity and experiences within higher education. However, we know very little about the role of social identity in shaping alumni engagement with their alma mater, specifically through philanthropic giving. Building upon social identity and social distance theories and the identity-based motivation model, I developed a philanthropic mirroring framework that posits that alumni engagement increases when alumni social identity is mirrored in solicitation efforts. Using my own population-based survey experiment, the National Alumni Giving Experiment (n = 1,621), I found that respondents who shared at least 1 marginalized social identity with students profiled in fundraising solicitations are more likely than others to assign more importance to the cause and to give greater amounts. Implications for research and practice are discussed.