In the spring, Illinois students will take new state assessments that reflect the rigor and relevance of the new Illinois Learning Standards. But some classmates will sit out and join the pushback against standardized testing. Opt-out advocates raise concerns about over-testing, and the resulting toll on students as well as the impact on classroom instruction. While this underscores real concerns, it risks marginalizing low-performing students who could be pushed out and distracts from efforts to continually improve a state assessment system that supports teaching and learning. This brief document highlights: states that recognize a student's right to opt out and those that do not; two opt-out bills that Illinois legislators will consider; an unintended consequence opt-out has for students; and how opt-out distracts from improvement efforts.