The Epsilon Corp is enhancing STEM major recruitment and retention among the highly diverse students at Kean University, an urban, comprehensive, public university in northern New Jersey. The project focuses on progressive recruitment and engagement of incoming students, intensive support and STEM skill building, community building with synergistic interaction among all STEM students, and campus-wide, culture-shifting and institutional changes. Epsilon Corps has five interwoven components: 1) engaging both undecided and intended incoming STEM students as Epsilon Explorers and encouraging them to choose STEM majors through peer-led exploration activities in the Summer Epsilon Institute and in Special Sections of Freshman Seminar; 2) engaging prospective and declared STEM majors with sophomore status as Epsilon Scholars and enhancing their STEM skills through mentoring and tutoring in Special Sections of Research & Technology; 3) engaging STEM juniors and seniors as Epsilon Peer Mentors and Project Leaders and enhancing their mentoring, project development and leadership skills through activities in special sections of an interdisciplinary general education course; 4) using this sequenced curricular support structure to build and sustain a synergistic STEM community of active learners and peer mentors, known collectively as Epsilon Corps); and 5) creating a campus-wide science-friendly atmosphere with coherent motivational and support activities, programs and facilities (Epsilon Celebration Day, Epsilon Awards and Scholarships, Epsilon Outreach, Epsilon Web Platform, and Epsilon Activities Center) to promote student interest in STEM careers and enhance their success in STEM programs.