Illinois Regulations § 26 IAC 125.120 Amendments

a) to correct any technical defects;

b) to conform to the evidence presented at the hearing;

c) to conform to new matters that arise at the hearing if it appears from the original and amended pleadings that the cause of action asserted in the amended pleading grew out of the same transaction or occurrence, or arose from or relate to the same disclosure period set forth in the original pleading. For the purpose of preserving the cause of action under those conditions, an amendment adding a person as a respondent relates back to the date of the filing of the original pleading so amended.