Over the last two decades, there has been interest in developing federal policies that focus on student outcomes in elementary and secondary education. Perhaps most prominently, the enactment of the No Child Left Behind Act of 2001 (NCLB; P.L. 107-110), which amended and reauthorized the Elementary and Secondary Education Act (ESEA), marked a dramatic expansion of the federal government's role in supporting standards-based instruction and test-based accountability, thereby increasing the federal government's involvement in decisions that directly affect teaching and learning. Under the ESEA, states are required to have standards in reading and mathematics for specified grade levels in order to receive funding under Title I-A of the ESEA. In response to this requirement, all 50 states and the District of Columbia have adopted and implemented standards that meet the requirements of the ESEA. Since the ESEA was last comprehensively reauthorized by NCLB, recent developments have taken place that have possibly played a role in the selection of reading and mathematics standards by states: (1) the development and release of the Common Core State Standards; (2) the Race to the Top (RTT) State Grant competition and RTT Assessment Grants competition; and (3) the ESEA flexibility package provided by the Department of Education (ED) to states with approved applications. These three changes have substantially changed the elementary and secondary education federal policy landscape. This short report answers common questions related to K-12 accountability provisions under the ESEA, Common Core State Standards, RTT, and the ESEA flexibility package. A more detailed discussion of the Common Core State Standards and their relationship to RTT grants and the ESEA flexibility package is available in CRS Report R43711, "Common Core State Standards and Assessments: Background and Issues," by Rebecca R. Skinner and Jody Feder. [For "Common Core State Standards and Assessments: Background and Issues," see ED607234.]