Every fall, school and district leaders make decisions about how to spend professional development dollars. Some of that money comes from local budgets, and a large share comes from Title II, Part A, which arrives in two installments and must be spent on activities that meet the federal definition of professional development. You have many options for professional development, like conferences, workshops, in-person trainings, online trainings, coaching, and more. The difficult part for you, though, is determining which professional development activities will be the most effective for your teachers. This article gives you some ideas on what effective professional development means. In this article, you will first learn about the research on what effective professional development looks like, summarized in seven characteristics that you can use as a checklist. The second is the definition of professional development written into the Every Student Succeeds Act (ESSA), which determines whether an activity is an allowable use of federal funds. Understanding this in more detail will help you choose professional development that improves instruction and also withstands a compliance review.