In the discourse on diversity in colleges and universities in the United States, an often-neglected population is nontraditional adult learners. This article explores this invisible aspect of undergraduate diversity, and addresses how competence-based education, which focuses on demonstrating the actual ability "to do," is an innovative approach that caters to adult learners' life phase and learning needs. College arguably is a youth-centric phase of life generally designed for the younger student. However, the stereotypical full-time student who lives on campus is actually a small percentage of the entire postsecondary population. Due to the demands of an increasingly competitive world of work, nontraditional adult learners will continue to seek out postsecondary education. Unfortunately, the credit hour system is a significant barrier for both entry and success of adult learners. Merits of competence-based education are discussed, and implications are provided to best meet this significant component of student diversity.