IDPH - Illinois Department of Public Health

Legitimation

When biological parents marry/enter into a civil union after a child is born, a legitimation process must be completed.

The following forms, Affidavit by Biological Mother and Affidavit by Biological Father will need to be submitted along with a certified copy of the marriage/civil union record or license. Instructions for how to complete the forms can be found here. If there is a man listed on the birth certificate to whom the mother/co-parent was married/in a civil union, a certified copy of their divorce/dissolution decree is required. The divorce/dissolution decree must specifically mention the child by name and indicate that the man listed on the birth certificate is not the father/co-parent. If the divorce/dissolution decree does not mention the child, then a court order of paternity is required. If there is a man listed on the birth certificate to whom the mother/co-parent was not married/in a civil union, a court order of paternity also is required. Contact your local court system for further details.

In cases where the biological parent(s) is deceased, further documentation is needed:

  • A notarized statement from a biological relative of the deceased parent(s). (This statement will need to indicate the person’s relationship to the deceased and that, while alive, the parent(s) did acknowledge the applicant was the biological child of that father/co-parent); or
  • A copy of an obituary notice (if the notice mentions the requestor as the child of the deceased); and
  • A certified copy of that parent's death record, and
  • Completed affidavits (write “deceased” in the area for signature).

Certified copies of the marriage/civil union record or license and affidavits will not be returned upon completion of the legitimation process.