The Diagnosis and Treatment Program provides medically necessary care and case management for infants, children and adolescents meeting program eligibility requirements. This care is delivered by California Children's Services (CCS)-paneled providers who meet program standards in tertiary care medical centers and in local communities.

The High-Risk Infant Follow-up (HRIF) program provides outpatient services to infants who meet the CCS medical eligibility criteria for CCS-approved neonatal intensive care unit (NICU), or had a CCS-eligible medical condition during their stay in a CCS approved NICU, even if they were never CCS clients during their NICU stay. These services include comprehensive history and physical examination, including neurological and developmental assessment, ophthalmological and audiological evaluations, and family psychosocial and home assessment, including coordination of HRIF services during the first three years of life.

The Department of Health Care Services (DHCS) Office of AIDS provides funding for the California Children's Services (CCS) HIV Children's Screening Program. CCS issues authorization to a CCS-approved Infectious Disease Immunology Disease Special Care Center (IDID SCC) for outpatient diagnostic services for infants and children under age of 21 who are at risk for HIV infection. Authorizations for diagnostic services are not to exceed six months.

Local California Children's Services (CCS) programs deliver Medical Therapy Program (MTP) services to children with cerebral palsy and other neuromuscular conditions. MTP provides medically necessary physical therapy (PT), occupational therapy (OT) and medical therapy conference (MTC) services to children who are medically eligible for the program. A medical therapy unit (MTU) team performs examinations and prescribes PT, OT, durable medical equipment (DME), and any other necessary medical interventions required to treat the child's CCS-eligible diagnosis. MTUs are located at select public schools as part of an interagency agreement with the California Department of Education.

The Newborn and Infant Hearing Screening Program offers hearing screening to all infants delivered in California Children's Services (CCS)-approved hospitals and CCS-approved neonatal intensive care units (NICUs) prior to the infant's discharge. Infants identified through the Newborn and Infant Hearing Screening Program who need diagnostic or treatment services are referred for health care and support services. Infants eligible for the CCS program are referred to CCS-approved Communication Disorder Centers for audiological services.

Orthodontic services are a benefit of the California Children's Services (CCS) program for children with severe malocclusion if evaluated by CCS-paneled orthodontists and determined to be medically eligible for orthodontic services as defined by CCS.