This study examines implementation of college-and-career-ready (CCR) education standards across five school districts in Ohio, Texas, California, Pennsylvania, and Massachusetts. Drawing on the policy attributes theory, we found that the specificity of districts' approaches to two long-recognized policy levers, curriculum and professional learning, was critical in shaping how stakeholders implemented and experienced CCR policies. We identified an approach we called "flexible specificity"--flexibility informed by ongoing data collection and evaluation that allowed districts to develop specific, useful guidance about curriculum and professional learning based on stakeholder needs. We present four shared practices characterizing this approach in two districts, analyzing why those districts seemed to find the right balance of specificity and flexibility while others struggled.