California Code, Family Code - FAM § 4551

(a) Does not apply to a temporary child support order.

(b) Applies to an application for modification of child support filed on or after January 1, 1992, but this chapter does not constitute the basis for the modification.

(c) Applies to an application for modification of child support in a case where the child support obligee has previously waived the establishment of a child support trust account pursuant to subdivision (b) of Section 4560 and now seeks the establishment of the child support trust account.

(d) Applies to an order or judgment entered by the court on or after January 1, 1993, ordering a child support obligor to pay a then existing child support arrearage that the child support obligor has unlawfully failed to pay as of the date of that order or judgment, including the arrearages which were incurred before January 1, 1992.