Too often under the various state-developed standards and assessments, accommodations for students with disabilities--a heterogeneous group with varied characteristics and needs--have not been adequately addressed or have been ignored. The Common Core State Standards (CCSS) initiative provides an historic opportunity to improve access to rigorous academic content standards for students with disabilities. However, implementation of CCSS must begin with the characteristics of these students clearly in mind. Because no single method or approach provides all students with access to the Common Core, the two most important areas that need to be addressed in implementation are instruction and assessment. As principals implement CCSS in their schools, key principles about educating students with disabilities must be on the radar screen: (1) Recognize that students with disabilities are a heterogeneous group and require individualized educational planning; (2) Distinguish between accommodations and modifications; (3) Support an environment and set expectations that teachers will understand, and use evidence-based practices; (4) Augment end-of-year state assessments with a schoolwide assessment program that can measure progress and growth; (5) Understand and support the alignment of individualized education programs (IEPs) with the CCSS; and (6) Hire and support the best special educators.