40 ILCS 5/9-108.1

Employees of County Department of Public Aid transferred to State employment by operation of law.

Employees of a County Department of Public Aid in a county of 3,000,000 or more population who, on January 1, 1974, are transferred by operation of law to State employment and who elect not to become members of the Retirement System established under Article 14 of this Code as of the date they become State employees shall retain their membership in the fund established in this Article 9 until February 1, 1974, at which time they shall become members of the System established under Article 14.