In North Dakota, an adult adoptee (age 18) may request the Department of Human Services to disclose identifying information concerning the birth parent(s). The Department must notify the child placing agency maintaining the adoption records and the agency must attempt to locate the birth parents.

If the agency is unable to locate the birth parent(s), information may not be released. If either of the birth parents has filed an affidavit denying consent to release of identifying information, information may not be released. Information may only be released if both birth parents have filed a consent.

Adult adoptees may request from the Department identifying information respecting adult biological siblings. Information will only be released with the written consent of the sibling and of any biological parents of the sibling if he or she knows their identity. 
N.D. Cent. Code, Ch. 14-15, 16.