Credit by Examination is a foundational practice of prior learning assessment that is widely accessible and has the potential to be a powerful tool to supporting adult learners entering and re-entering postsecondary education. WICHE conducted a meta-analysis of existing literature to understand the impact CLEP and WorkKeys, two types of credit-by-examination, can have on student success. A robust evaluation of the CLEP program found those scoring above a 50 to have shorter time to degrees and higher post-credential earnings. Predominately used in the workforce setting, those completing WorkKeys and obtaining a National Career Readiness Certificate have seen positive workforce outcomes, such as higher earnings and higher rates of employment. More research is needed on both CLEP and WorkKeys usage to better inform PLA policies, particularly in how credit by examination can be used to better support adult learners.