The Common Core of Data (CCD) nonfiscal surveys consist of data submitted annually to the National Center for Education Statistics (NCES) by state education agencies (SEAs) in the 50 states, the District of Columbia, Puerto Rico, the four U.S. Island Areas (American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Virgin Islands), the Department of Defense (DoD) dependent schools (overseas and domestic), and the Bureau of Indian Education (BIE). In order to provide data comparable across states to the maximum extent feasible, NCES and SEAs have worked since the 1950s to develop and accept common data items and definitions. SEAs report school-, agency-, and state-level education data for the CCD through the U.S. Department of Education's EDFacts collection system. The purpose of the CCD nonfiscal surveys is to provide a listing of all schools and agencies providing free public elementary and secondary education, along with basic descriptive statistical information on each school and agency listed. The CCD includes all settings in which free public education is provided to children. The Public Elementary/Secondary School Universe file includes data for the following variables: NCES school ID number, state school ID number, name of the school, name of the agency that operates the school, mailing address, physical location address, phone number, school type, operational status, locale code, latitude, longitude, county number, county name, full-time-equivalent (FTE) classroom teacher count, low/high grade span offered, Congressional district code, school level, free lunch eligible students, reduced-price lunch eligible students, total free and reduced-price lunch eligible, student totals and detail (by grade, by race/ethnicity, and by sex), and pupil/teacher ratio. This report contains an introduction to the NCES Common Core of Data Public Elementary/Secondary School Universe Survey: School Year 2009-10, Version Provisional 2a and a user's guide. The following are appended: (1) Record Layout for the Common Core of Data Public Elementary/Secondary School Universe Survey: School Year 2009-10; (2) Value Distribution, Field Frequencies, and Data Tables for the Common Core of Data Public Elementary/Secondary School Universe Survey: School Year 2009-10; (3) Glossary for the Common Core of Data: School Year 2009-10; and (4) State Notes for the Common Core of Data: School Year 2009-10.