(1) The Director of Human Services or the authorized representative of the director may enter into agreements with persons or families found suitable for the placement of children in the legal custody of the Department of Human Services.
(2) The agreement shall provide for the custody, care, education, maintenance and earnings of the child placed for a time fixed in the agreement but not to exceed the time when the child reaches the age of 21 years.
(3) The agreement shall be signed by the person assuming the foster care and by the director or the authorized representative of the director.
(4) If the agreement provides for payments to the person assuming the foster care, the department shall make these payments.