The bill aims to reduce prescription drug costs by removing barriers to accessing biosimilar medicines and interchangeable biological products. It amends several sections of Washington state law, including RCW 48.43.420, which outlines the requirements for health carriers regarding prescription drug utilization management. Key provisions include the establishment of a clear process for patients and prescribing practitioners to request exceptions to drug coverage, the requirement for health carriers to disclose all relevant rules and criteria, and the stipulation that exception requests must be granted under certain conditions. Additionally, starting January 1, 2026, health carriers may require patients to try a biosimilar before covering the equivalent branded prescription drug.

Further amendments include changes to RCW 69.41.120 and RCW 69.41.125, which modify the rules around substituting drugs. The new language allows pharmacists to substitute therapeutically equivalent drugs or interchangeable biological products unless explicitly instructed otherwise by the prescriber. It also clarifies that pharmacists may substitute an interchangeable biological product if the consumer's out-of-pocket cost for the interchangeable product is lower than that of the prescribed biological product. These changes are intended to enhance patient access to more affordable medication options while ensuring that health care providers and patients are informed throughout the process.

Statutes affected:
Original Bill: 48.43.420, 41.05.410, 69.41.120, 18.64.245
Substitute Bill: 48.43.420, 41.05.410, 69.41.120, 18.64.245
Engrossed Substitute: 48.43.420, 41.05.410, 69.41.120, 18.64.245