California Code, Health and Safety Code - HSC § 127444

(a) This article does not prohibit a hospital from uniformly imposing charges from its established charge schedule or published rates or preclude the recognition of a hospital's established charge schedule or published rates for purposes of applying any payment limit, interim payment amount, or other payment calculation based upon a hospital's rates or charges under the Medi-Cal program, the Medicare Program, workers' compensation, or other federal, state, or local public program of health benefits.

(b) This article does not prohibit a hospital, debt collector, or debt buyer from selling or otherwise transferring patient debt to an organization that is exempt from taxation under Section 501(c)(3) of the Internal Revenue Code 1 for the explicit purpose of the tax-exempt organization abolishing the patient debt by cancellation of the indebtedness, or otherwise prohibit payment of the patient's debt by a third party.

(c) A health care service plan, insurer, or any other person shall not reduce the amount it would otherwise reimburse a claim for hospital services because a hospital has waived, or will waive, collection of all or a portion of a patient's bill for hospital services in accordance with the hospital's charity care or discount payment policy, notwithstanding any contractual provision.