Head Start provides education, health and social services to eligible families with the goal of ensuring the children enrolled are ready to start school. Education includes pre-school education to nationally set standards that have become the de-facto standards[citation needed] for pre-school in the USA. Health services include screenings, health check-ups and dental check-ups. Social services provide family advocates to work with parents and assist them in accessing community resources.
Eligibility for Head Start services is largely income-based (100% of the federal poverty level), though each locally-operated program includes other eligibility criteria such as disabilities and services to other family members. As of late 2006, up to 10% of any funded program's enrollment can be from over-income families or families experiencing emergency situations. All programs provide full services to children with disabilities.
An important update to the Head Start Reauthorization bill signed by President Bush on December 12, 2007 is the importance of Head Start to serve the homeless children in America. Homelessness is defined as a child "who lack a fixed, regular, and adequate nighttime residence." This includes not only the typical homeless child in a shelter or other outreach program, or those living in motels or cars but also the children who are living in a "sharing the housing of others due to loss of housing, economic hardship, or similar reason." (http://www.naehcy.org). These homeless children must be sought out by the local Head Start and have to be served within a reasonable time frame. Head Start programs must communicate with the local school districts to help in providing services to the younger siblings of those the school has identified as homeless as well as helping older siblings of the preschool children Head Start has identified.