The Department of Health and Human Services may make payments as needed on behalf of a ward of a child placement agency with special needs after the legal completion of the child’s adoption as authorized by the federal adoption assistance program, 42 U.S.C. § 673. Such payments to adoptive parents may include maintenance costs, medical and surgical expenses, and other costs incidental to the care of the child. Payments for maintenance and medical care shall terminate on or before the child’s nineteenth birthday.