The Every Student Succeeds Act (ESSA) comprehensively reauthorized the Elementary and Secondary Education Act of 1965 (ESEA). Among other changes, the ESSA amended federal K-12 educational accountability requirements for states and local educational agencies (LEAs) receiving ESEA funds, including those regarding the identification, support, and improvement of high schools with low graduation rates. In addition to new accountability rules, the ESSA provided the first definition of the high school graduation rate in federal education law. States and LEAs have been reporting their rates using the same definition, originally laid out in 2008 regulations, since the 2010-2011 school year. The national graduation rate for the Class of 2016 was 84.1%--the highest rate recorded using the new methodology. The graduation rate for the Class of 2011 was 79.0%. This national-level improvement has been accompanied by improvements in nearly every state and across all reported groups of students, including all racial and ethnic subgroups, low-income students, English learners, and students with disabilities. Still, graduation rate gaps persist among several student subgroups. At the state level, 27 states were above the national average in 2016 and 23 were below. Three states graduated fewer than 75% of their students, nine states graduated 75%-79.9%, eleven states graduated 80%-84.9%, seventeen states graduated 85%-87.9%, and ten states graduated 88% or more. Importantly for ESSA accountability implementation, analysis of 2014-2015 school-level data reveals that as many as 16% of high schools may fail to graduate at least one-third of their students. Thus, there are potentially thousands of high schools nationwide that may be identified for intervention in the coming years.