This document is written primarily for policy makers and state department of education staff who are considering through-year assessments, as well as consultants and contractors state departments rely on. The document identifies essential things to consider when designing or evaluating a through-year assessment program. The paper is organized into five sections. The first section provides a definition of through-year assessment, the main motivations and purposes for through-year assessments, and the tools for specifying an assessment design, including theories of action, claims, and validity arguments. The second section describes key design aspects that every through-year assessment program must address, and some options for those design aspects that distinguish through-year models. The third section discusses emerging examples of specific through-year assessment designs in terms of their design choices, challenges, and trade-offs. The fourth section provides suggestions for evaluating through-year assessment programs that go beyond current evaluation requirements for state summative assessments, such as federal Peer Review. The fifth and final section provides conclusions and a view to the future.