As the number of end of course (EOC) tests has increased along with an expansion of their role in accountability, development and implementation decisions are more important than ever. This process starts with articulating how the assessment fits into a credible theory of action that describes how all elements of the system will work together to promote the desired educational outcomes. Once clarified, policy makers are encouraged to carefully study the full range of policy, technical, and practical considerations associated with the intended purposes and uses of the assessment, many of which have been discussed in this document. Finally, an ongoing monitoring and evaluation plan should accompany implementation to support system improvement. By so doing, state leaders are best positioned to leverage the promise of EOC tests and mitigate unintended consequences. Appendix includes: Results of Survey of State EOC Test Implementation. (Contains 3 figures, 6 tables, and 14 footnotes.)