This is the fourth biennial report to Congress on the implementation of the "Elementary and Secondary Education Act's" Title III State Formula Grant Program (also known as the English Language Acquisition State Grants Program). This report provides information reported by states to the U.S. Department of Education regarding services provided for children served under Title III to ensure that all limited English proficient (LEP) students attain English proficiency and are achieving in reading or language arts and in mathematics at the same high level set by the states for all students. Under the State Formula Grant Program, states also are accountable for the education of immigrant children and youth. In this report, the U.S. Department of Education presents data reported by the 50 states, the District of Columbia, and the Commonwealth of Puerto Rico on how well states are meeting their goals for LEP students' achievement in English language arts and math and in English proficiency for school years (SY) 2008-09 and 2009-10. However, not all states provided all the data requested. Therefore, throughout this document, the number of states providing information is noted. This report has been prepared for multiple audiences, including members of Congress, State and national organizations, State and local educational personnel, and researchers. To ensure that the information is clear and useful to these audiences, the data from all sources are clearly identified through citations and in the reference list. This report provides a list of abbreviations and definitions. The following appendices are included: (1) Summary of Results Organized According to the Nine Statute-Based Report Elements; and (2) Comments from States on Calculations to Determine Number of Teachers Needed in 5 Years. [For the third biennial report, see ED564283.]