S.C.

*698 *593 This dispute centers on child support arrears owed by respondent G.S. (father) to respondent S.C. (mother) pursuant to an order issued by the trial court in 1995. 1 In March 2015, appellant and intervenor Santa Clara County Department of Child Support Services (the Department) brought a motion seeking to increase father's monthly child support payments. In the course of litigation over the motion, father for the first time informed the Department and the trial court that he had been incarcerated from 1998 to 2005. Prior to 2015, father had not sought a modification of the child support order.

In February 2016, the trial court granted the Department's motion to increase father's monthly payments but also, on the court's own motion, awarded father "equitable credit" for father's period of incarceration. Invoking its authority under Family Code section 290, 2 the trial court reduced the amount owed by father in child support by approximately $70,000.

The Department appeals the trial court's February 2016 order, arguing that the trial court lacked authority to retroactively adjust father's arrears. For the reasons discussed further below, we agree. Although legislation…