Ill. Admin. Code tit. 56 § 2905.20
A claimant who indicates in the claimant's application for benefits that the individual is not a citizen of the United States must produce evidence that the individual is not ineligible. The presentation of a valid U.S. Immigration and Naturalization Service (INS) Form I-151 or a valid U.S. Citizenship and Immigration Services (USCIS) Form I-551, commonly known as the "green card", or other similar documents issued by INS or USCIS will be sufficient for a finding that the noncitizen is eligible under Section 614 of the Act. Without the presentation of these documents, the burden of coming forth with evidence of eligibility is upon the noncitizen. Documents tending to show eligibility for benefits under this Section may be submitted for verification or clarification to INS or USCIS; however, benefits shall not be withheld pending such verification unless the claimant admits that the claimant is not legally in the United States or unless the documents appear to be altered.
Ill. Admin. Code tit. 56, § 2905.20