California Code, Family Code - FAM § 17460

(a) As necessary, the department shall seek reciprocal agreements with other states to improve its ability to collect child support payments from out-of-state obligated parents on behalf of custodial parents residing in California.  The department may pursue agreements with the Internal Revenue Service, as permitted by federal law, to improve collections of child support delinquencies from out-of-state obligated parents through cooperative agreements with the service.

(b) The California Child Support Enforcement System shall, for purposes of this article, include the capacity to interface and exchange information, if feasible, with the Internal Revenue Service, to enable the immediate reporting and tracking of obligated parent information.

(c) The department shall enter into any interagency agreements that are necessary for the implementation of this article.  State departments and boards shall cooperate with the department to the extent necessary for the implementation of this article.  Out of any money received from the federal government for the purpose of reimbursing state departments and boards for their actual and reasonable costs incurred in complying with this section, the department shall reimburse those departments and boards.  To the extent that money is not provided by the federal government for that purpose, and subject to the annual Budget Act, the state shall fund departments and boards for their costs in complying with this section.