One of the most substantial concerns surrounding remedial education at the postsecondary level is the impact that it may have on student success and completion. While Parts 1 and 2 of this series of briefs focused on providing context necessary to understand the concept and purpose of remediation and what postsecondary populations are assessed to need it, this brief, as well as those to follow, will focus on two of the most substantial questions surrounding developmental education in higher education: (1) Does it work?; and (2) Does it represent a barrier to persistence and completion of college? Key takeaways from Part 3 of this series include: (1) While a large number of full-time students are assessed to need remedial work prior to completing credit-bearing coursework, many of them fail to complete necessary remedial work within their first year; (2) As discussed in Part 2 of this series, the percentage of first-time, full-time undergraduate students assessed to need remediation at community colleges is much higher than at four-year institutions. In addition, community college students are much less likely to complete remedial courses in their first year of enrollment; (3) At community colleges, students are equally likely to complete remedial courses in math as in English; and (4) At four-year institutions, students are much more likely to complete assigned remedial work in math than in English. This brief will focus on remedial course completion in higher education as a way of evaluating the impact that remedial assessment and completion may have on an undergraduate student's enrollment behavior and academic success in the first year of postsecondary education. The analysis contained in this report will examine data at Maryland community colleges and four-year public institutions for all full-time students. Additionally, as Part 2 of this series showed, there are substantial differences across demographic groups regarding students' likelihood of being assessed to need developmental work. Accordingly, further analysis will review whether there might be differences in outcomes across demographic groups, including gender, age group, or race/ethnicity. [For Part 1, see ED604255. For Part 2, see ED604259. For Part 4, see ED611938.]