40 ILCS 5/9-238
Employees of a County Department of Public Aid in counties of 3,000,000 or more population who transfer to the employment of the State in positions of comparable or substantially similar responsibilities or duties shall retain their earned and accrued rights and benefits established under this Article if they do not receive a refund of their contributions hereunder.
Such employees who on the effective date of the transfer are recipients of any disability benefit hereunder shall continue to receive their benefit from the fund established under this Article.
If, after such transfer, an employee becomes disabled or dies under circumstances which would have qualified him or any beneficiaries claiming through him for disability, death, widow's, or survivorship benefits payable under this Article had such transfer of employment not occurred, where such benefits are not payable under Article 14 or under the reciprocal provisions of Article 20, the employee or his beneficiaries shall be entitled to the benefits prescribed in this Article 9 from the fund established hereunder.
40 ILCS 5/9-238