Provides that, in an arbitration proceeding or a court of law, health care providers' billing statements certified under RCW 70.02.070 for treatment provided to a patient are presumed to be the reasonable value of health care treatment and are admissible in evidence to establish that the charges are reasonable and customary charges in the community. The presumption that the charges are reasonable and customary may be rebutted by a preponderance of the evidence. The presumption does not shift the burden of proof that the medical treatment was for medical conditions proximately caused by another's fault.