Over the past 40 years, the Head Start program has delivered early education and support services to 23 million low-income preschool children and their families. In addition to early education, Head Start programs must provide children and families with access to a range of comprehensive services, including parenting resources, health screenings and follow-up, and social services. This policy brief describes the characteristics of Head Start and Early Head Start children, families, staff, and programs during the 2003-2004 program year. The data come from Program Information Reports (PIR), which are submitted to the U.S. Department of Health and Human Services by all federal Head Start grantees. This brief is part of a series of briefs CLASP has released that analyze Head Start data from 2001, 2002, and 2003 to identify key trends since the program was last reauthorized in 1998. This brief, uses 2004 data and note changes of 5 percentage points or more since 2001. In some instances, smaller changes are highlighted if they are particularly noteworthy. (Contains 5 figures and 15 endnotes.)