California Code, Government Code - GOV § 17615.8

(a) The commission shall establish a procedure for reviewing, upon request, any apportionment or base year entitlement of a local agency or school district.

(b) Local agencies and school districts which request such a review shall maintain and provide those records and documentation as the commission or its designee determines are necessary for the commission or its designee to make the required determinations.  With the exception of records required to verify base year entitlements, the records may not be used to adjust current or prior apportionments, but may be used to adjust future apportionments.

(c) If the commission determines that an apportionment or base year entitlement for funding costs mandated by the state does not accurately reflect the costs incurred by the local agency or school district for all mandates upon which that apportionment is based, the commission shall direct the Controller to adjust the apportionment accordingly.  For the purposes of this section, an apportionment or a base year entitlement does not accurately reflect the costs incurred by a local agency or school district if it falls short of reimbursing, or overreimburses, that local agency's or school district's actual costs by 20 percent or by one thousand dollars ($1,000), whichever is less.

(d) If the commission determines that an apportionment or base year entitlement for funding costs mandated by the state accurately reflects the costs incurred by the local agency or school district for all mandates upon which that apportionment is based, the commission may, in its discretion, direct the Controller to withhold, and, if so directed, the Controller shall withhold the costs of the commission's review from the next apportionment to the local agency or school district, if the commission review was requested by the local agency or school district.