The Center on Education Policy (CEP), an independent nonprofit organization, has been monitoring national adequate yearly progress (AYP) data going back to school year 2005-06. In April 2011, the author and her colleagues released a report with estimates of the number of schools in the nation and each state that did not make AYP in 2010, as well as trends from 2006 through 2010 in the national percentage of schools not making AYP ("Update with 2009-10 Data and Five-Year Trends: How Many Schools Have Not Made Adequate Yearly Progress?"). This new report updates their April report in three respects. First, the author and her colleagues have added estimates of the number of schools that did not make AYP in 2011, based on tests administered in school year 2010-11. These data were collected from what they believe to be the most reliable sources available at the time of their research. Second, the 2011 estimates have been added to their trend data to produce six-year trends in the percentages of schools not making AYP for the nation and each state. Third, the 2010 estimates in their April report have been updated with the official numbers of schools that did not make AYP in 2010, obtained from Consolidated State Performance Reports submitted by states to the U.S. Department of Education. These are the main findings: (1) An estimated 48% of the nation's public schools did not make AYP in 2011. This marks an increase from 39% in 2010 and is the highest percentage since NCLB took effect; (2) In 24 states and the District of Columbia, at least half of the public schools did not make AYP in 2011. In a majority of the states (43 and D.C.), at least one-fourth of the schools did not make AYP; and (3) The percentage of public schools not making AYP in 2011 varied greatly by state, from about 11% in Wisconsin to about 89% in Florida. (Contains 2 tables, 1 figure and 1 footnote.)