In response to the claimant’s argument that the Board’s Guidelines have shifted the burden of proof from the employer to the carrier the Court held that there was nothing with in the Worker’s Compensation Law that ever precluded the Board from requiring proof of medical necessity from the claimant’s health care provider. In fact, the Court of Appeals went further to noting that WCL § 13-a presupposes that the treating medical provider has already submitted a first opinion for the needed treatment. Regarding the presumption under WCL § 21(5), the Court of Appeals held that the presumption remains as to the facts contained in medical report, but that a claimant must first demonstrate medical necessity for the treatment.