This descriptive analysis provides a statistical profile of California's Title I school districts in program improvement. As an independent analysis of these districts in the aggregate, it is intended to inform the context for district improvement as California rolls out and refines its district intervention strategies. A key finding of this study is that the district level of California's accountability system is identifying problems that are missed at the school level. This study finds that more than a third of California's Title I school districts (344 of 961) did not make adequate yearly progress in 2005/06, including all but 22 of the state's districts in program improvement. Implications for research and practice are presented. Appended are: (1) research questions, data sources, and methodology; (2) the 159 California districts in program improvement in 2006/07, with their 2005/06 student enrollments; and (3) summary of California's district accountability system. (Contains 2 boxes, 9 tables, 4 figures, and 11 notes.) [This report was prepared for the Institute of Education Sciences (IES) by Regional Educational Laboratory West administered by WestEd.]