Through-year assessment is enjoying a surge of attention. A through-year assessment program is: (1) Administered in multiple distinct sessions during a school year; and (2) Intended to support (a) the production and use of a summative determination, and (b) one additional aim. More than a dozen states are designing, piloting, or implementing versions of this assessment model to replace their current end-of-year summative test for accountability. As an organization that advises states on assessment and accountability, we understand the complexities of these kinds of assessment models. Through-year programs may provide a number of benefits, but these potential benefits must be clearly articulated and evaluated in light of their required trade-offs. The authors urge states to proceed with caution. This paper outlines ten interrelated considerations for states exploring through-year designs for their federally mandated state assessment program.