Competency-based education (CBE) is widely viewed as an innovative alternative to traditional higher education, yet most programs serve only a narrow slice of the postsecondary population. Few are intended for adults who need to boost basic skills in order to succeed in college coursework. However, if designed with the needs of a broader range of learners in mind, CBE could be an important piece of the national movement to increase educational access, equity, and credential attainment. This paper is part of a series that recommends specific features likely to help more underprepared students in CBE settings master college-ready skills, persist in their postsecondary studies, and ultimately earn credentials. This paper concludes the series by acknowledging--and addressing--the four biggest concerns identified by Jobs for the Future's research about CBE for underprepared learners: (1) Flexible pacing, which for some students can accelerate progress, can stall progress for others; (2) Online delivery models, which are common among CBE programs, show weak outcomes for underprepared learners; (3) Assessment, which is frequent in CBE models, can create high-stakes environments that impede the success of underprepared learners who have a history of test anxiety; and (4) Competencies, which form the foundation of CBE, can disadvantage underprepared learners if they do not directly align to future education or employment. Research shows that while CBE holds great promise, it can also present barriers to student success. Contains endnotes.