This national study, which comprehensively reviews 311 virtual schools operating in the United States, finds serious and systemic problems with the nation's full-time cyber schools. Despite virtual schools' track record of students falling behind their peers academically or dropping-out at higher rates, states and districts continue to expand virtual schools and online offerings to students, at high cost to taxpayers. The advocates of full-time virtual schools are several years ahead of policymakers and researchers, and new opportunities are being developed and promoted largely by for-profit entities accountable to stockholders rather than to any public constituency. The report's authors conclude that continued rapid expansion of full-time cyber schools is unwise. More research is needed; and to enable such research, state oversight agencies need to require more, and better refined, data. Financial controls and funding unique to cyber schools need to be established. The following appendices are available for download: (1) Summaries of Enacted State Legislation Pertaining to Virtual Schools; (2) Numbers of Full-time Virtual Schools and the Students They Serve by State; (3) Demographic Characteristics of Students Enrolled in Full-Time Virtual Schools; and (4) State Performance Ratings, Adequate Yearly Progress Status, and Reasons for Not Meeting AYP. http://nepc.colorado.edu/publication/virtual-schools-annual-2013 (Each section contains a list of notes and references.) [Contributors of the research brief include: Gary Miron, Luis Huerta, Jennifer King Rice, Larry Cuban, Brian Horvitz, Charisse Gulosino, and Sheryl Rankin Shafer.]