When child custody, visitation, or support is contested in a divorce or other legal proceeding, courts may appoint a guardian ad litem (often an attorney with experience in family law matters) to investigate and make independent, objective recommendations to the court of what is in the best interest of the child. The guardian ad litem will typically interview the child, the parents, and other people who have contact with the child, and may subpoena witnesses to testify at court hearings, examine and cross-examine witnesses at hearings. The guardian ad litem may also testify regarding her investigation of the circumstances, conclusions, and recommendations to the court.

In Montana, when child custody, visitation, or support is contested in a divorce or other legal proceeding, the court has the authority to appoint a guardian ad litem (GAL) to represent the best interests of the child. The GAL, who is often an attorney with experience in family law, is tasked with conducting an independent investigation into the child's situation. This includes interviewing the child, parents, and others in the child's life, as well as potentially subpoenaing witnesses to testify in court. The GAL has the authority to examine and cross-examine witnesses during hearings. After completing their investigation, the GAL will report their findings and make recommendations to the court regarding custody, visitation, or support arrangements that would best serve the child's needs and welfare. The court considers the GAL's recommendations when making its final decision, although the recommendations are not binding on the court.