WASHINGTON · plumber
Journey Plumber (PL01)
Washington State Department of Labor & Industries — Plumber Certification →Scope of Work
A Journey Plumber (PL01) is qualified to perform all phases of plumbing construction, installation, alteration, and repair in Washington. Source: WA L&I Plumber Certification (https://lni.wa.gov/licensing-permits/plumbing/plumber-certification/).
Experience and Training
8,000 hours of plumber-trainee experience in a state-approved plumbing apprenticeship program or under a licensed Journey Plumber. The trainee must hold an active Washington Plumber Trainee certificate (PL0X or PT0X) while accruing hours, and must submit hour reports to L&I to qualify to sit for the Journey exam. Washington State Apprenticeship and Training Council registered programs satisfy the hour requirement on program completion. Out-of-state experience is evaluated under WAC 296-400A. Source: WA L&I Plumber Certification (https://lni.wa.gov/licensing-permits/plumbing/plumber-certification/).
Military Crosswalk
L&I accepts verified military plumbing experience under RCW 18.106 and applicable WAC sections. Relevant ratings include Navy Utilitiesman (UT), Army Plumber (12K), Marine Hygiene Equipment Operator (1171), and Air Force Water and Fuel Systems Maintenance (3E4X1). Applicants submit DD-214 and training transcripts with the L&I military credit request.
Exam
Administered by PSI Services at L&I-approved testing centers. The exam is open-book and based on the Uniform Plumbing Code (UPC) edition currently adopted in Washington, plus WAC 296-400A and Washington plumbing law. Core topics include drainage, waste and vent sizing, water supply and distribution, fuel-gas piping, fixtures and appliances, backflow prevention, water heaters, and Washington-specific rules. Verify current exam fee at WA L&I Plumber Examination (https://www.licensing.lni.wa.gov/licensing-permits/plumbing/plumber-examination).
Reciprocity
Washington does not maintain a formal journey-to-journey plumber reciprocity agreement. Out-of-state journey plumbers apply through the L&I equivalency process, which evaluates hours, training, and prior exam content under WAC 296-400A. Applicants typically document equivalent hours and pass the Washington exam.
Renewal and CE
Journey Plumber certification renews every 3 years on the certificate holder's birthday. Renewal fee is $227.90 (2026). Effective July 1, 2021, renewal requires 24 hours of continuing education per 3-year cycle, composed of: a minimum of 12 hours of Uniform Plumbing Code content, plus a minimum of 4 hours of Industry-Related Electrical (IRE) content; the remaining 8 hours may be any combination of Code, IRE, or Industry-Related Plumbing (IRP) content. CE must be on file with L&I before renewal is processed. Source: WA L&I Plumber Continuing Education (https://www.licensing.lni.wa.gov/licensing-permits/plumbing/continuing-education).
Scope Limitations
The PL01 is an individual certification. Contracting for plumbing work in one's own name requires a Washington contractor registration and, where applicable, a specialty endorsement. Medical gas, water-supply protection specialist work, and some specialized fuel-gas installation carry additional endorsement requirements documented on the WA L&I Plumber Certification landing page.