DC has a larger percentage of students in charter schools than any state. To help oversee DC charter schools, Congress established two authorizers--the Board of Education (BOE), which has an Office of Charter Schools responsible for oversight, and the independent Public Charter School Board (PCSB). Congress required the GAO to conduct a study of the authorizers. This report, which completes GAO's May 2005 study--examines: (1) authorizers' resources; (2) oversight practices; and (3) actions taken once charter schools close. GAO examined BOE and PCSB monitoring reports, revenue and expenditure documents, and closure procedures. GAO recommends that the BOE Office of Charter Schools implement a risk-based oversight system to target monitoring to new and at risk charter schools. Appended are: (1) Objectives, Scope, and Methodology; (2) Comments from the DC Board of Education; (3) Comments from the PCSB; and (4) GAO Contact and Staff Acknowledgments. Contains 4 tables, 4 figures, and a list of abbreviations.