The bill introduces a new section to chapter 74.09 RCW, mandating that, starting January 1, 2026, medical assistance programs must cover provider payments for rapid whole genome sequencing for enrollees up to one year of age who are receiving inpatient hospital services in intensive care or high acuity pediatric care units. This coverage is contingent upon specific medical conditions being met, such as the presence of multiple congenital abnormalities or unexplained epilepsy, and requires that alternative causes for the illness have been ruled out. The bill emphasizes the importance of timely molecular diagnosis to guide clinical decision-making and improve health outcomes for children with rare diseases.

Additionally, the bill stipulates that if a managed care organization uses a capitated or bundled payment model, reimbursement for rapid whole genome sequencing must be provided separately unless a negotiated rate that includes this service has been established. The definition of "rapid whole genome sequencing" is also clarified, encompassing a comprehensive investigation of the human genome with results delivered in less than 14 days, including various sequencing methods involving the patient and their biological parents. This legislation aims to enhance access to critical genetic testing for families, particularly those with lower incomes, and to facilitate quicker diagnoses and treatment options for rare diseases.