Child welfare agencies seek to ensure the well-being of children and their families, including protecting children from abuse or neglect and ensuring that they have a safe and permanent home. As the U.S. Constitution has been interpreted, states have the primary obligation to ensure child welfare. At the state level, the child welfare "system" consists of state and local judges and other court personnel, prosecutors, law enforcement personnel, and public and private social service workers. These representatives of various state and local entities investigate allegations of child abuse and neglect, provide services to families in their own homes, remove children from homes if necessary, and supervise and administer payments for children in out-of-home settings. Federal involvement in child welfare is tied to the financial assistance it provides to states to conduct these activities. In FY2008, Congress appropriated just under $7.9 billion for child welfare purposes. The bulk ($4.6 billion) of this money was appropriated to reimburse states for the cost of providing foster care for children who meet federal eligibility criteria (estimated 43% of national foster care caseload in FY2006). Beginning in the early 1960s, the federal government has paid for part of the cost of foster care for children who would have been entitled to federally assisted cash welfare had they continued to live in their own homes. (In essence, the cash aid was expected to follow the child into foster care.) States had primary responsibility to pay the full foster care costs for other children who were removed from their homes. In the 1996 welfare reform law ( P.L. 104-193 ), Congress ended the entitlement to cash aid for needy families with children and converted funding for this purpose to a block grant. At the same time, it continued to require that only children removed from homes that would have met the eligibility requirements for cash aid under the state's pre-1996 welfare-reform rules would be eligible for federal foster care assistance. As a condition of receiving these foster care and other child welfare funds, states are required to abide by a series of federal child welfare policies. Federal child welfare policies focus, overall, on ensuring safety and well-being for all children served. However, the most specific and extensive requirements are designed for the protection of children in foster care, especially to ensure them a safe and permanent home. These protections must generally be provided to all children in foster care, regardless of whether they meet federal foster care eligibility criteria. State compliance with the majority of these federal requirements is checked as part of the Child and Family Services Review (CFSR). A state that is not in "substantial conformity" with federal child welfare policy—as determined by the review—must implement a Program Improvement Plan ( PIP). The state typically has two years to implement a PIP. The PIP must successfully address the compliance issues identified by the CFSR or the state faces a loss of a part of their federal child welfare funding. In FY2006, an estimated 905,000 U.S. children, or about 12.1 children for every 1,000 in the general population, were found to be victims of abuse or neglect; an estimated 1,530 children died due to abuse or neglect in that year. The rate of reported child maltreatment victims has been about 12 children per 1,000 children in the national population in every year since 1999. This rate is well below the recorded highs in the early to mid-1990s (1992-1996), when the rate ranged around 15 victims for every 1,000 children in the population and the number of child victims was counted as more than 1 million annually. (See Table 1 .) For FY2006, states reported 64% of child victims experienced neglect, 16% were found to have experienced physical abuse, 9% sexual abuse, 7% psychological maltreatment, 2% medical neglect, and 14% "other abuse." These shares were fairly constant between 2000 and 2006, although the rate of children found to have experienced neglect increased somewhat while the rate of children found to have experienced physical abuse or sexual abuse declined somewhat. Preliminary estimates show 510,000 children were in foster care on the last day of FY2006 (or about 6.8 per every 1,000 children in the general population). This represents a modest decline from the estimated 511,000 children in care on the last day of FY2005, but is well below the recorded high of 567,000 children in care on the last day of FY1999 (when there were about 8.0 children in foster care per 1,000 in the population). (See Table 1 .) Overall, the national foster care caseload declined by about 10% between FY1999 and FY2006; however, this decline has not been shared by all states. Between FY1999 and FY2006 (most recent year state-level data are available), less than half of all the states (24, including Puerto Rico and the District of Columbia) reported reductions in their foster care caseload, ranging from a less than 1% decline in Connecticut (40 children) and Michigan (200 children) to a nearly 47% decline in Illinois (16,000 children). Along with Illinois, California and New York posted the greatest numerical and percentage change declines in their caseloads between the last days of FY1999 and FY2006: California's caseload dropped by close to 40,000 children (34% decline); New York's caseload declined by more than 21,000 children (41% decline). Over the FY1999-FY2006 time period, slightly more states (27) posted increases in their caseloads. These ranged from an increase of about 3% (more than 300 children) in Massachusetts to increases of 93% (close to 900 children) in Idaho, 89% in Texas (nearly 15,000 children) and 86% in Iowa (more than 4,000 children). In addition, five states (WY, SD, OK, AZ, and WV) saw caseload increases in their foster care caseloads ranging from roughly one-third to two-thirds between the last day of FY1999 and the last day of FY2006. The overall number of children in care on the last day of a given year rises or falls depending upon both the number of entries to foster care, that is children who are removed from their homes in a given year, and the number of exits in that same year, that is children reunited with their families, adopted, emancipated, or placed in another permanent setting. Nationally, the number of children reported as having exited foster care has risen from an estimated 250,000 in FY1999 to an estimated 289,000 in FY2006. (However, this is understood as an undercount because some states do not report all exits from foster care. ) Nationally, the number of children who entered foster care may be trending up. During FY2006 (most recent year for which data are available), the number of children who entered foster care in FY2006 was estimated as 303,000 compared to 293,000 children who entered in FY1999. Table 1 indicates that this represents a rate of about 4.1 children per 1,000 in the population in both of those years. However, during the period of greatest recorded decline in the national caseload, FY2000 through FY2004, the rate of children entering foster care also declined, reaching a low point of 3.9 in FY2003. Table 1 shows national estimates of the total number and the rate (i.e. the number of children per 1,000 in the population) who were found to be victims of child maltreatment, who entered foster care, and who were in care on the last day of the fiscal year. Federal child welfare policy has sometimes been considered synonymous with foster care policy, and most federal dedicated funding and policy proscriptions are related to children in foster care. At the same time, the mission of child welfare agencies, as described in federal policy, and the group of children and families those agencies work with, is far broader. During FY2006 (most recent data available), states received allegations of abuse or neglect related to roughly six million children. Many of these allegations were "screened out," and no further attention was given to the case. A screen out might occur because the alleged behavior does not match the state definition of child abuse or neglect, because the case is transferred to another agency (considered by the child protective services agency to be more appropriate), because not enough information was provided to follow up on the allegation, or for other reasons. In the end, states conducted investigations or assessments of abuse or neglect involving some 3.6 million children during FY2006 and found more than 905,000 children to be victims of child abuse or neglect. States also reported providing post-investigation services to an estimated 1.3 million children, including some of those who were found to be victims as well as some who were not found to be victims. Most of these children (77%) were served in their homes, and the remainder were removed to foster care. Although the number of children receiving some services after the investigation (1.3 million) exceeds the number of victims (905,000), not all victims received post-investigation services. Instead, the data reported by states suggest that roughly three out of every five victims received any services following the investigation. Overall, states reported that, among children found to be victims of child maltreatment, an estimated 22% were removed to foster care, and roughly equal portions of the remaining victims were either served in their homes (37%) or received neither in-the-home nor out-of-the home services following the investigation (41%). Among the children who were not found to be "victims" in the investigation, states reported that more than 4% were removed to foster care, close to 26% received services in the home, and the remaining 70% received neither in-the-home nor out-of-the-home services following the close of the investigation.