Five-plus years into the experiment with new “college- and career-ready standards” (of which Common Core is the most notable and most controversial example), we know little about teachers’ implementation and the ways policy can support that implementation. This paper uses new state-representative teacher survey data to characterize the degree of standards implementation across three states—Kentucky, Ohio, and Texas. We also investigate teachers’ perceptions of the extent to which the policy environment supports them to implement the standards. We find a great deal of variation in perceptions of policy, with Ohio teachers perceiving policy to be less supportive than Kentucky or Texas teachers. Teachers in all states are mostly implementing the content in new standards, but they are also teaching a good deal of content they should not—content that has been deemphasized in their grade-level standards. Perceptions of policy do not explain much of the variation in instruction, contrary to our theory. If greater attention is not paid to supporting teachers to implement the standards and reduce coverage of deemphasized content, we worry the standards will not have much effect.