In this section, “seriously emotionally disturbed” means a condition that is: Manifest in an individual younger than 18 years or, if the individual is in a residential treatment center, younger than 21 years; Diagnosed according to the current diagnostic classification system that is recognized by the Secretary; and Characterized by a functional impairment that substantially interferes with or limits the child’s role or functioning in the family, school, or community activities. The Department shall apply to the Health Care Financing Administration of the federal Department of Health and Human Services for a home– and community–based services waiver under § 1915(c) of the federal Social Security Act in order to receive federal matching funds for services to seriously emotionally disturbed individuals who would otherwise require institutionalization in a residential treatment center. The Department shall apply to the Health Care Financing Administration of the federal Department of Health and Human Services for a home– and community–based services waiver under § 1915(c) of the federal Social Security Act in order to receive federal matching funds for services to autistic children aged 1 through 21 years who would otherwise require institutionalization in an institution for the developmentally disabled. In accordance with subsection (b)(1) and (2) of this section, the services to be provided for seriously emotionally disturbed individuals or autistic children may include: Respite services; Family training and education; Day treatment services; Therapeutic integration services; Intensive individual support services; Therapeutic living services; Intensive in–home intervention services; and Specialized case management services. The State matching funds required to cover the Medicaid costs under the waiver for autistic children shall be certified or otherwise provided by the Maryland State Department of Education, local school systems, and local lead agencies. The State matching funds required to cover the Medicaid costs under the waiver for seriously emotionally disturbed individuals shall be certified or otherwise provided by the Maryland State Department of Education, local school systems, local lead agencies, and the Behavioral Health Administration.