Cal. CIV § 2782.9

(a) All contracts, provisions, clauses, amendments, or agreements contained therein entered into after January 1, 2009, for a residential construction project on which a wrap-up insurance policy, as defined in subdivision (b) of Section 11751.82 of the Insurance Code, or other consolidated insurance program, is applicable, that require an enrolled and participating subcontractor or other participant to indemnify, hold harmless, or defend another for any claim or action covered by that program, arising out of that project are unenforceable.

(b) To the extent any contractual provision is deemed unenforceable pursuant to this section, any party may pursue an equitable indemnity claim against another party for a claim or action unless there is coverage for the claim or action under the wrap-up policy or policies. Nothing in this section shall prohibit a builder or general contractor from requiring a reasonably allocated contribution from a subcontractor or other participant to the self-insured retention or deductible required under the wrap-up policy or other consolidated insurance program, if the maximum amount and method of collection of the participant’s contribution is disclosed in the contract with the participant and the contribution is reasonably limited so that each participant may have some financial obligation in the event of a claim alleged to be caused by that participant’s scope of work. The contribution shall only be collected when and as any such self-insured retention or deductible is incurred by the builder or general contractor and in an amount that bears a reasonable and proportionate relationship to the alleged liability arising from the claim or claims alleged to be caused by the participant’s scope of work, when viewed in the context of the entirety of the alleged claim or claims. Any contribution shall only be collected from a participant after written notice to the participant of the amount of and basis for the contribution. In no event shall the total amount of contributions collected from participants exceed the amount of any self-insured retention or deductible due and payable by the builder or general contractor for the claim or claims. However, this requirement does not prohibit any legally permissible recovery of costs and legal fees to collect a participant’s contribution if the contribution satisfies the requirements of this subdivision and is not paid by the participant when due.

(c) This section shall not be waived or modified by contractual agreement, act, or omission of the parties.