Section 48.46.510 - Phenylketonuria(1) The legislature finds that: (a) Phenylketonuria is a rare inherited genetic disorder.(b) Children with phenylketonuria are unable to metabolize an essential amino acid, phenylalanine, which is found in the proteins of most food.(c) To remain healthy, children with phenylketonuria must maintain a strict diet and ingest a mineral and vitamin-enriched formula.(d) Children who do not maintain their diets with the formula acquire severe mental and physical difficulties.(e) Originally, the formulas were listed as prescription drugs but were reclassified as medical foods to increase their availability.(2) Subject to requirements and exceptions which may be established by rules adopted by the commissioner, any agreement for health care services delivered or issued for delivery or renewed in this state on or after September 1, 1988, shall provide coverage for the formulas necessary for the treatment of phenylketonuria. Such formulas shall be covered when deemed medically necessary by the medical director or his or her designee of the health maintenance organization and if provided by the health maintenance organization or upon the health maintenance organization's referral. Formulas shall be covered at the usual and customary rates for such formulas, subject to contract provisions with respect to deductible amounts or copayments.