The Education Equality Index is the first national comparative measure of the achievement gap between students from low-income families and their peers across the state, measured at the school and city levels. Through the Education Equality Index, Education Cities, in partnership with GreatSchools and Schoolzilla, has amassed one of the largest collections of income-focused proficiency data at the school and grade levels. They have also developed a nationally-unique methodology that allows the comparison of student performance across cities even though they use different assessments and have set different achievement standards. This first report using the Education Equality Index data focuses on schools with significant concentrations of students from low-income families. The data identifies schools with small or nonexistent achievement gaps where at least 51 percent of the student population receives free or reduced price lunch (a common measure of economic disadvantage). They have chosen to focus on these schools because 51 percent is the national average of students from low-income families. To be clear, there are many schools that serve fewer than 51 percent students who receive free or reduced price lunch with small or nonexistent achievement gaps. However, it is believed important to highlight schools with significant concentrations of students from low-income families as their efforts and achievements are worthy of special attention. A decision was made to highlight up to 10 schools in each city. In future reports, it is planned to release additional data and analysis of schools that serve the full spectrum of student populations. The Education Equality Index is not intended to serve as a broad measure of school quality; rather, it is a narrow measure of equality of student outcomes. For too long, discussions about school quality have failed to account for the persistent achievement gap between children from low-income families and their peers. Education Cities believes that any conversation about school quality must include a focus on equality as well. Too many state accountability systems give credit to supposedly high-performing schools, even if those schools maintain significant achievement gaps between children from different backgrounds. The Education Equality Index makes it easy for parents, educators, and policymakers to bring equality into any discussion of school quality at the city or state level. Key findings include: (1) In most major U.S. cities, the achievement gap between students from low-income families and their peers stagnated or grew between 2011-14; (2) Nearly every major U.S. city is home to a large or massive achievement gap; (3) Some of the biggest U.S. cities like El Paso, New York and San Francisco are among the 10 cities with the smallest achievement gaps; (4) Of the 100 major U.S. cities, eight have small achievement gaps, 25 have large achievement gaps and 67 have massive achievement gaps; (5) Some cities with high concentrations of free and reduced lunch students are those that are most equitable; (6) Two of the three major U.S. cities with the smallest achievement gaps--Hialeah and Miami--are both in the same school district--Miami-Dade County Public Schools; (7) Only two in 10 students from low-income families attend schools that have successfully closed the achievement gap; (8) The majority of major U.S. cities are home to fewer than 10 school serving primarily students from low-income families that have a small or nonexistent achievement gap; (9) Schools with massive achievement gaps in one year are highly likely to have a massive achievement gap the next year; (10) Half of the schools recognized in the 100 biggest U.S. cities as having a nonexistent or small achievement gap are elementary schools; and (11) On average, only six percent of students from low-income families in the biggest 100 cities in the U.S. attend a school with no achievement gap.