According to research, comprehensive early intervention programs can positively affect the progress of children with developmental delays and children at risk of having a disability. Services provided by these programs may include speech language therapy, family counseling, and home visits. Research has linked early intervention services to improvements in toddlers’ behavior, interactions between parents and children, infant development, and overall quality of life for children and their families. Additionally, research has found increased mental development and better vocabulary and reasoning skills for children who received early intervention services when compared with those who did not receive these services. Findings from the National Early Intervention Longitudinal Study (NEILS), a research project sponsored by the Department of Education, has found that parents report a high degree of satisfaction after receiving 3 years of early intervention services, reporting that their families are better off and that early intervention services are having “a lot” of impact on their child’s development. IDEA is the primary federal education law for infants, toddlers, children, and youth with disabilities. Grants to states for early intervention services and special education and related services for children with disabilities and their families are provided mainly through Parts C and B of the act. These parts have different histories and are generally administered by different agencies at the state level. IDEA Part C was established to ensure that infants and toddlers, from birth to age 3, with disabilities or at risk of developing a disability, and their families receive appropriate early intervention services. Part C focuses on, among other things, enhancing the development of infants and toddlers with disabilities by providing services in a natural environment, such as the home or a child care center. This part of the law seeks to improve the capacity of the family to meet the child’s needs and reduce educational costs by minimizing the need for special education when the child is older. Part B, in contrast, requires that services, to the extent possible, be provided in educational settings, such as regular classrooms. Part B, which includes state grants for children and young adults ages 3 through 21, and Part B Section 619 preschool grants for children 3 through 5, aims to ensure that children with disabilities have access to a free appropriate public education. Funding for Part B is significantly larger than for Part C programs. In fiscal year 2004, Part C was funded at $444 million, and approximately 279,000 infants and toddlers received services. In contrast, Part B state grants and the Section 619 supplement for preschool services were funded at $10 billion and $388 million, respectively, in 2004. Approximately 6 million children were provided services under Part B state grants, and over 693,000 children were provided preschool services under Part B Section 619. To meet Part C goals, states use funds to develop a statewide, coordinated, multidisciplinary, interagency system of early intervention services for infants and toddlers with disabilities and their families. Developing such a system includes designating a lead agency, preparation and dissemination of materials on the availability of services, defining eligibility criteria, and delivering services. To this end, each state has a designated lead agency responsible for the administration, supervision, and monitoring of Part C. In contrast to Part B, which is led by state education departments, Part C is led by the health department in 16 states, education departments in 11 states, and other departments, including combined health and human services departments, in the remaining 23 states. States are expected to leverage funding, services, and resources from other sources to provide early intervention services. Each state must have a continuous process of public awareness activities and evaluations designed to identify and refer as early as possible all young children with disabilities and their families who are in need of early intervention services. By law, public awareness efforts should include disseminating information to parents on available early intervention services and to all primary referral sources, especially hospitals and physicians. Efforts may also include television ads, pamphlets, and posters describing IDEA Part C and how parents can access services for their child. Once a child is referred and suspected of having a disability, states are required to conduct an evaluation to determine if the child meets the state’s eligibility criteria. In order to be eligible for federal funds under Part C, IDEA requires that states provide services to any child under 3 years of age who is developmentally delayed. These delays must be measured by appropriate diagnostic instruments and procedures or validated by professional opinion, and may occur in one or more of the areas of development—including cognitive, physical, communicative, social or emotional development, and adaptive behavior, such as feeding or toileting. States must also provide services to those children that have a diagnosed mental or physical condition that has a high probability of resulting in developmental delay. However, states are free to define what constitutes a developmental delay and specify how this will be measured. In addition, states may choose to serve children who are at risk of having a substantial developmental delay. These may include biological risks, such as low birth weight, and environmental risks, such as parental substance abuse. Once an eligible delay has been detected, service coordinators work with parents and others to match children with services specific to their needs. Part C requires that every state make certain services available, including special therapies such as physical, occupational, or speech language therapy, and family supports such as home visits. For example, an occupational therapist may come to a child’s home to teach a child to draw, which involves hand and eye coordination. The law also requires that services be provided in children’s natural environments. Figure 2 illustrates the typical process in early intervention programs. Children eligible for Part C can receive early intervention services until they turn 3 years of age. Part C funds can be used to provide services to children from their third birthday to the beginning of the following school year, but as of 2004 only 14 states have adopted such a policy. Thirty states allow for the use of Section 619 preschool funds to provide services to children before their third birthday. As a child approaches age 3, the local education agency (LEA) determines the child’s eligibility for Part B Section 619 preschool services. If eligible for Part B Section 619, the child might also be eligible for extended school year services. An extended school year ensures that a child can continue receiving services even when schools are not in session, for example, during the summer. According to Education, most children under Part B do not receive extended school year services. By contrast, Part C is a year-round program. Eligibility for an extended school year is determined on an individual basis and is generally based on how much a child will regress and the time it will take to regain lost skills. During the most recent reauthorization of IDEA, in 2004, Congress gave states the option of allowing children to continue to receive services under Part C until they become eligible for kindergarten. States vary in both the criteria used to establish eligibility for services and the means used to assess whether children fit these criteria, but these differences are not consistently related to the percentage of children receiving early intervention services. While Part C is intended to serve infants and toddlers from birth to age 3, the majority of children receiving services nationwide and in most states are toddlers between ages 2 and 3. Officials in states we visited told us that despite their various public awareness efforts, there are a number of challenges in identifying all children eligible for services, specifically reaching children whose families speak limited English or live in rural areas. Comprehensive data on the number of children who could benefit from early intervention are not available; many conditions covered by Part C—such as emotional disorders and learning disabilities—are not systematically tracked. Nationwide, states’ eligibility criteria for Part C services vary, with most states specifying the amount of delay in development a child must experience to be eligible for services, while a few rely exclusively on the judgment of a multidisciplinary clinical team. IDEA generally gives states the discretion to determine specific eligibility criteria and diagnostic procedures. For example, Part C specifies that a child have an established condition that has a high probability of resulting in a developmental delay, or that a delay is present in one or more areas of development—cognitive, physical, communicative, social or emotional, or adaptive—and that all states allow for the use of informed clinical opinion in their evaluation. However, states can determine the amount of delay a child must experience in order to be eligible for services. Part C also gives states discretion to identify the appropriate diagnostic instruments to measure the extent of a child’s delay or to rely exclusively on the informed opinion of professionals. For example, Arizona requires a 50 percent delay in one or more aspects of early childhood development, such as physical or emotional development. New Jersey’s eligibility criteria vary depending on the number of areas in which a child is developmentally delayed. The state requires that children have a 33 percent delay in one area of development, but a 25 percent delay in two or more areas of development. The Centers for Disease Control and Prevention noted that the significance and implication of a given percentage delay vary across areas of development. For instance, according to CDC, a 25 percent delay in motor skills development has much different implications for services for a child than a 25 percent delay in language development. Other states’ eligibility criteria are based on the number of months or standard deviations from age norms. For example, in Massachusetts, a 24-month-old child functioning at an 18-month-old level could be eligible for services. In Georgia, a child whose cognitive abilities are at least two standard deviations less than the abilities of most children at the same age would be eligible for services. Hawaii does not specify a percentage delay and instead relies on the judgment of a multidisciplinary team, which generally includes either a speech therapist or special educator and an occupational or physical therapist. Despite wide variation in how states define eligibility, variation among states in the percentage of children served is not consistently explained by eligibility criteria.