(750 ILCS 46/205)
    Sec. 205. Proceedings to declare the non-existence of the parent-child relationship.
    (a) An action to declare the non-existence of the parent-child relationship may be brought by the child, the birth mother, or a person presumed to be a parent under Section 204 of this Act. Actions brought by the child, the birth mother, or a presumed parent shall be brought by verified complaint, which shall be designated a petition. After a presumption under Section 204 of this Act has been rebutted, parentage of the child by another man or woman may be established in the same action, if he or she has been made a party.
    (b) An action to declare the non-existence of the parent-child relationship brought under subsection (a) of this Section shall be barred if brought later than 2 years after the petitioner knew or should have known of the relevant facts. The 2-year period for bringing an action to declare the non-existence of the parent-child relationship shall not extend beyond the date on which the child reaches the age of 18 years. Failure to bring an action within 2 years shall not bar any party from asserting a defense in any action to declare the existence of the parent-child relationship.
    (c) An action to declare the non-existence of the parent-child relationship may be brought subsequent to an adjudication of parentage in any judgment by the man adjudicated to be the parent pursuant to a presumption in paragraphs (a)(1) through (a)(4) of Section 204 if, as a result of deoxyribonucleic acid (DNA) testing, it is discovered that the man adjudicated to be the parent is not the father of the child. Actions brought by the adjudicated father shall be brought by verified petition. If, as a result of the deoxyribonucleic acid (DNA) testing that is admissible under Section 614 of this Act, the petitioner is determined not to be the father of the child, the adjudication of paternity and any orders regarding the allocation of parental responsibilities, parenting time, and future payments of support may be vacated.
    (d) An action to declare the non-existence of the parent-child relationship brought under subsection (c) of this Section shall be barred if brought more than 2 years after the petitioner obtains actual knowledge of relevant facts. The 2-year period shall not apply to periods of time where the birth mother or the child refuses to submit to deoxyribonucleic acid (DNA) testing. The 2-year period for bringing an action to declare the non-existence of the parent-child relationship shall not extend beyond the date on which the child reaches the age of 18 years.
(Source: P.A. 99-85, eff. 1-1-16; 99-769, eff. 1-1-17.)