CA Civ Proc Code Section 706.052

(a)

Except as provided in subdivision (b), one-half of the disposable earnings (as defined by Section 1672 of Title 15 of the United States Code) of the judgment debtor, plus any amount withheld from the judgment debtor’s earnings pursuant to any earnings assignment order for support, is exempt from levy under this chapter where the earnings withholding order is a withholding order for support under Section 706.030.

(b)

Except as provided in subdivision (c), upon motion of any interested party, the court shall make an equitable division of the judgment debtor’s earnings that takes into account the needs of all the persons the judgment debtor is required to support and shall effectuate such division by an order determining the amount to be withheld from the judgment debtor’s earnings pursuant to the withholding order for support.

(c)

An order made under subdivision (b) may not authorize the withholding of an amount in excess of the amount that may be withheld for support under federal law under Section 1673 of Title 15 of the United States Code.