This report examines publicly reported participation and performance data for the alternate assessment based on modified achievement standards (AA-MAS). The authors' analysis of these data included all states publicly reporting AA-MAS data, regardless of whether they had received approval to use the results for Title I accountability calculations. Data were examined for school years 2006-07 through 2009-10. Because most states had not yet reported data for 2009-10, the authors focused most of their analyses on 2006-07 (six states with an AA-MAS), 2007-08 (eight states with an AA-MAS), and 2008-09 (eight states with an AA-MAS). Their analysis of AA-MAS participation and performance reporting indicated that most states implementing these assessments were reporting some data publicly. For participation data across years, seven states reported participation data by grade. Most of these states reported numbers of students tested; a few states reported the percent of students tested on the AA-MAS. Three appendices are included. (Contains 13 tables and 12 figures.)