California Code, Health and Safety Code - HSC § 1566.25

(a) The county of residence shall agree to pay the placement county the actual costs of providing services to a child placed in a community care facility outside his or her county of residence by a placement agency, as defined in Section 1536.1, that are incurred by the probation department, social services department, health department, or mental health department of the placement county for which the placement county is not otherwise reimbursed.

(b) Claims made by the county of placement to the county of residency pursuant to subdivision (a) shall include documentation and shall be paid within 30 days of submission of these claims.

(c) For the purposes of this section, the county from where the child was placed in the community care facility shall be considered the county of residency.