For more than 50 years, colleges and universities have used a range of different methods to award college credit for learning that takes place outside of the classroom--particularly learning from work, life, and military experiences. These methods--often called prior learning assessment (PLA) or credit for prior learning (CPL)--value the learning that many adult students bring with them to college. An important question is whether earning credit through PLA makes a difference for the adult student in terms of their ability to complete a postsecondary credential. This study examined data provided by 72 postsecondary institutions about the enrollment, credit-earning, and degree-earning of more than 465,000 students of all ages, focusing in particular on more than 232,000 adult learners (defined as students age 25 and older) from 69 of the participating institutions that were able to provide the most detailed data on PLA credit-earning. While this report provides clear and compelling evidence that PLA can be an important tool to support adult student credential completion, there is still much work to do. Institutions need to provide multiple methods for adults to have various types of learning evaluated and recognized. PLA options should be promoted early and often, so that the recognition of learning becomes integrated into the institution's culture, and indeed, the learn-and-work ecosystem. And institutions need to invest in staff who can oversee PLA promotion, ensure its integrity, create greater access, and build acceptance across the institution. [This report has been revised from the original due to the discovery of an error in the dataset. For the original version of this report, see ED608563. For the updated executive summary, see ED609771. For the updated appendices, see ED609772.]