There is a critical need to broaden access to engineering education in order to build a strong and diverse engineering workforce. However, four-year engineering programs are typically designed for students who are calculus-ready, so many students who wish to study engineering may need additional preparation and time to succeed. The NSF-funded Redshirt in Engineering Consortium was formed in 2016 to enhance the ability of academically talented but underprepared students from low-income backgrounds to successfully graduate with bachelor's degrees in engineering. The "redshirt" name is derived from the practice of giving some college athletes an extra year of eligibility to prepare for college-level competition. Implementation and evaluation of Redshirt programs across six universities participating in the Redshirt in Engineering Consortium revealed important lessons for schools considering a Redshirt program, including the importance of alignment with a college-wide commitment to increasing equity; sufficient funding for a full-time administrator; ability to fit shared curricular experiences within existing degree requirements; and attention to Redshirt's unique role in the landscape of existing equity programs. Over the course of the five-year grant, understanding of the Redshirt in Engineering Model also evolved to center on five key pillars: (1) a focus on supporting high-achieving students from low income or educationally disadvantaged backgrounds; (2) an expected five-year graduation timeline; (3) personal, professional, and study skills development; (4) intrusive advising; and (5) community-building and social support. This article defines the key elements of the Redshirt in Engineering Model, describes model adaptations and lessons learned through implementation and evaluation across the consortium, and suggests considerations for other institutions interested in implementing a Redshirt in Engineering program.