Child Supp. Guid. 9.4
In ordering child support, the court should determine the amount of support specified by the guidelines. There shall be a rebuttable presumption that the amount of child support which would result from the application of the guidelines prescribed by the supreme court is the correct amount of child support to be awarded. That amount may be adjusted upward or downward, however, if the court finds such adjustment necessary to provide for the needs of the children or to do justice between the parties under the special circumstances of the case. In determining the necessity of an adjustment, the custodial parent's child care expenses under rule 9.11A are to be considered. The appropriate amount of child support is zero if the noncustodial parent's only income is from Supplemental Security Income (SSI) paid pursuant to 42 U.S.C. 1381a.
Child Supp. Guid. 9.4