State divorce courts can order custodial parents to waive their right to claim a dependent child for income tax purposes, the Idaho Supreme Court says.

The high court ruled 4-1 Friday to uphold 6th District Judge Peter McDermott's order, earlier endorsed by the Idaho Court of Appeals, that Teresa Ann Rohr sign a written waiver of the federal tax exemption for the child over whom she won custody in a July 1986 divorce from William Rohr.But the court also decided unanimously that the magistrate who handled the original divorce case failed to adequately address Teresa Ann Rohr's petition for modification of child support. It returned the case for further action.

Teresa Ann Rohr argued that under federal law, only a custodial parent may claim the income tax exemption for a dependent child, even though the other parent may be making child-support payments.

The Supreme Court disagreed, saying divorce courts should not be forced into taking tax consequences into account in dividing property. Justice Larry Boyle wrote for the majority that denying courts the authority to order the custodial parent to sign the waiver would result in "a circuitous process that is cumbersome at best and beset with the likelihood of error."