A school board may employ school social workers who have graduated with a master’s or higher degree in social work from an accredited graduate school of social work and have such additional qualifications as may be required by the State Board of Education and who hold a Professional Educator License with a school support personnel endorsement for school social work pursuant to Section 21B-25 of this Code. Only persons so licensed and endorsed may use the title “school social worker”. A school social worker may provide individual and group services to the general student population and to students with disabilities pursuant to Article 14 of this Code and rules set forth in 23 Ill. Adm. Code 226, Special Education, adopted by the State Board of Education and may provide support and consultation to administrators, teachers, and other school personnel consistent with their professional qualifications and the provisions of this Code and other applicable laws. School districts may employ a sufficient number of school social workers to address the needs of their students and schools and may maintain the nationally recommended student-to-school social worker ratio of 250 to 1. A school social worker may not provide such services outside his or her employment to any student in the district or districts that employ the school social worker.