Establishing Paternity in Montana

The mother and alleged father can sign a paternity acknowledgment form from the Department of Public Health and Human Services, which files it; filing creates a presumption of paternity (if another man is a presumed father, his written consent is needed). A signer may rescind within 60 days after signing by filing a notice of withdrawal with the department, with an affidavit that the other parent received a copy. After that, or once a court or administrative order involving the signer establishes paternity or support, the acknowledgment becomes an irrebuttable presumption with the force of a court judgment, which can be set aside only for fraud, duress or material mistake of fact. A paternity test showing a 95% or higher probability also creates a presumption.