Using data from the 2004-2007 National Study of Living Learning Programs, the only national dataset offering longitudinal information on outcomes associated with living-learning (L/L) program participation, this study investigated the role of L/L programs and other college environments in the professional outcome expectations of women in science, technology, engineering, and mathematics (STEM) majors. Specifically, we examined an overall measure of professional outcome expectations, along with participants' anticipation of the chances that they will "get a good job in their field," "achieve success in their career," and "combine a professional career with having a balanced personal life." Findings indicated that attending a coeducational STEM L/L program and discussing academic and career issues with peers were positively related with three of the outcome measures. Additional findings spoke to the importance of self-efficacy and interactions with diverse peers in the development of professional outcome expectations among women in STEM. Implications are presented for higher education institutions' efforts to support coeducational and women-only STEM-related L/L programs, peer and faculty interactions, and diverse peer interactions.