Although animal dissection is common in classrooms, growing concerns for animal welfare and advances in nonanimal teaching methods have prompted the creation of policies that allow students to choose humane alternatives to classroom animal use. We assessed the prevalence and content of policies that allow students to opt out of animal dissection in states and large public school districts across the United States — data that have not previously been collected or analyzed. We found that such policies exist at the state level in 22 states ( plus the District of Columbia) and in many large public school districts in the other remaining states. These data illustrate that at least 63% of students in U.S. public schools have access to some kind of dissection choice, although the content of these policies varies widely. We discuss these results and recommend components of a comprehensive student dissection-choice policy.