This bill creates a new "medical use of psilocybin program" in the Washington State Department of Health, titled the "Washington medical psilocybin act," and adds a new chapter to Title 43 RCW while amending RCW 69.50.101. It defines psilocybin (limited to naturally occurring psilocybin and its active metabolite, not synthetic analogs) and establishes that producers, approved clinicians, and qualified patients (age 18 or older) participating in the program are not subject to arrest, prosecution, or penalty for conduct authorized by the chapter. The chapter does not apply to FDA‑approved clinical trials, use in animals, or persons under 18, and it does not shield unauthorized activities (including existing offenses under chapter 69.50 RCW), driving under the influence liability, or medical malpractice claims. The bill creates two license types regulated by the department: a producer license to grow, process, manufacture, and package psilocybin products for sale to approved clinicians, and a clinician participation license to dispense or administer psilocybin to qualified patients. Clinician licensing requires an active unrestricted health license with prescribing authority, department‑required training and continuing education, and a fingerprint‑based background check (WSP and FBI) paid by the applicant. The department must set fees to cover administration and enforcement, may deny/suspend/revoke licenses for noncompliance, and may audit, inspect, or require records; refusal to comply can lead to disciplinary action including permit suspension or revocation. The bill changes procedures and regulatory standards: it requires direct delivery of psilocybin products from producers to approved clinicians (prohibits third‑party pharmacies/distributors under this chapter), detailed clinician recordkeeping (paper or electronic) subject to state and federal privacy/security laws and department inspection, secure electronic registry reporting of deidentified and limited patient information for program oversight, and confidentiality protections for registry data. The department is authorized to promulgate rules on treatment protocols, approved settings, dosage standards (including an outpatient microdosing model), training, product preparation and testing standards, storage and chain‑of‑custody, and data collection. Producers must comply with applicable controlled substances, food safety, occupational and environmental laws and may use accredited labs for testing. The act also amends broader definitions in RCW 69.50.101 (including exclusions for psilocybin used medically and various cannabis‑related definitions and lot‑number requirements) and contains timing provisions: the act takes effect July 1, 2028; section 12 expires June 30, 2027; section 13 takes effect June 30, 2027. Important implementation details are not included in the provided text: the full chapter language, specific rule text, licensing application processes, fee amounts, exact definitions of terms left to department rule (for example "adequate supply," "approved setting," and specific dosage limits), record retention periods, and other operational timelines are missing.

If enacted, Washington’s Department of Health would run a regulated medical psilocybin program that lets licensed producers grow and test psilocybin mushrooms and licensed clinicians directly dispense or supervise patient use for adults 18 and older. Practically, that creates a new regulated supply chain: producers must meet manufacturing, packaging, testing, and food‑safety rules and deliver products directly to approved clinicians; clinicians must complete department training, pass fingerprint background checks at their own expense, keep required records, and report minimal patient treatment data into a secure state registry. The program excludes FDA clinical trials, use by people under 18 or animals, and does not shield people from unrelated criminal charges or DUI or malpractice liability. The biggest impacts fall on the Department of Health (new rulemaking, inspections, audits, registry operation paid by license fees), producers and clinicians (new licensing, training, testing, storage, security, and compliance costs and the risk of discipline or permit revocation for violations), and labs/health jurisdictions (testing and enforcement roles). Many important operational details are left to department rules—for example exact dosages, what counts as an “adequate supply,” fee amounts, permit application procedures, and specific reporting fields—so the timing, costs, and day‑to‑day requirements remain uncertain until those rules and fee schedules are adopted; the act’s main provisions take effect July 1, 2028, with some related sections effective or expiring earlier.