Plumber License Requirements in Washington
- Training hours
- 8000 hrs
- Upfront cost
- $524.8
- Exam
- Journey Level Plumber Examination
- Renewal cycle
- Every 3 years
- Issuing board
- Washington State Department of Labor & Industries (L&I), Plumber Certification Program
How to get licensed
- 1
Meet the prerequisites
Be at least 16 years old. 16 is the minimum age to register as a Plumber Trainee, the mandatory entry point into the 8,000-hour experience pipeline that precedes the Journey Level exam — since trainee registration is a prerequisite to becoming eligible for the exam, it is recorded as the effective minimum age. L&I's Journey Level exam application and certification forms do not describe a criminal-history or background-check requirement for the individual plumber certification (this differs from Washington's separate business-level plumbing contractor registration, which is bonded/insured and outside the scope of this personal-certification record). [1]
- 2
Complete approved training
Complete 8000 hours of training. Candidates must complete at least 4 years (8,000 hours) as a registered Plumber Trainee working under the direct supervision of a journey-level or certified plumber, of which at least 2 years (4,000 hours) must be commercial/industrial installation work. Experience is documented via annual Affidavits of Experience rather than a mandatory classroom program, so approvedProgramRequired is false. Trainees must also complete 8 hours of L&I-approved continuing education each year to renew their trainee certificate. [1]
- 3
Journey Level Plumber Examination
Pass the Journey Level Plumber Examination (fee: $80). Three closed-book portions, each 90 minutes with a 70% passing score: (1) Journey Level code and general trade knowledge, 100 questions from Uniform Plumbing Code chapters 1-10, 15-17 and amendments; (2) Waste and Vent Journey Level Drawings, a 25-item sizing exercise from UPC Chapter 7; (3) Water Sizing Journey Level Drawings, a 25-item sizing exercise from UPC Chapter 6. All three portions must be passed. The $80 fee (paid to PSI) covers all three portions taken together; retesting an individual failed portion costs $50. This is separate from L&I's own $202.10 exam-eligibility application fee (recorded under fees.application). The exam fee is valid for 1 year from payment. [2]
- 4
Submit your application
Submit your application to Washington State Department of Labor & Industries (L&I), Plumber Certification Program with the $202.1 application fee. [3]
- 5
Receive your license
Once your application is approved, Washington State Department of Labor & Industries (L&I), Plumber Certification Program issues your Journey Level Plumber Certification for Washington.
Fees
| Fee | Amount |
|---|---|
| Application fee [3] | $202.1 |
| License fee [3] | $242.7 |
| Renewal fee [3] | $242.7 |
| Journey Level Plumber Examination [2] | $80 |
Per L&I's current Plumber Exam Application (form F627-008-000, revised 07-2026), the Journey Level exam-eligibility application fee is $202.10, paid to L&I before PSI will schedule the exam. Once the exam is passed, a $242.70 Journey Level certification fee is owed within 90 days (recorded as license); renewal every 3 years is also $242.70.
Renewal & continuing education
Renew every 3 years. 24 continuing education hours required per cycle.
Journey Level Plumber certification renews on the licensee's birthdate every 3 years, for a $242.70 renewal fee (late renewal doubles the total to $485.40). 24 hours of continuing education are required before expiration: a minimum of 12 hours must be Plumbing Code and a minimum of 4 hours must be IRE (industry-related electrical); the remaining 8 hours may be from any approved category.
Reciprocity
Endorsement/reciprocity from another state is available.
Washington has a reciprocal agreement with Idaho: an active Idaho Journey Level plumber card, emailed with photo ID to L&I, qualifies for a Washington certificate without retesting. Oregon has no reciprocal agreement. Applicants with an active license from any other state, or documentation of qualifying U.S. military plumbing experience, may email their credentials to L&I for case-by-case consideration; absent an approved reciprocity/consideration route, out-of-state plumbers must pass the Washington Journey Level exam like any other applicant. No interstate plumbing licensure compact exists for this occupation.
Cost calculator
- $202.1
- $242.7
- $80
Frequently asked questions
How much experience does Washington require for a Journey Level Plumber certification?
4 years (8,000 hours) as a registered Plumber Trainee under a certified journey-level plumber, including at least 2 years (4,000 hours) of commercial/industrial work, documented via annual Affidavits of Experience.
Who administers the Washington Journey Level Plumber exam and what does it cost?
PSI Services LLC, on contract with L&I. It's three closed-book, 90-minute portions (100-question code/trade knowledge, plus waste/vent and water-sizing drawing exercises), each requiring 70% to pass, for an $80 PSI fee — on top of a separate $202.10 L&I application fee to become eligible to test.
How much does a Washington Journey Level Plumber certification cost overall?
$202.10 to apply for exam eligibility, $80 for the PSI exam itself, and $242.70 for the certification once you pass — with renewal also $242.70 every 3 years.
How often does a Washington plumber certification need to be renewed?
Every 3 years, on your birthdate, with 24 hours of continuing education required (at least 12 hours Plumbing Code, at least 4 hours industry-related electrical, and 8 hours from any approved category).
Can an out-of-state plumber get certified in Washington without retesting?
Yes, if you hold an active Idaho Journey Level card — Washington has a direct reciprocal agreement with Idaho. Other out-of-state licenses or qualifying military plumbing experience are considered case-by-case; otherwise you must pass the Washington exam.
Sources
- [1] lni.wa.gov/licensing-permits/plumbing/plumber-certification/plumber-trainee — accessed 2026-07-12
- [2] test-takers.psiexams.com/api/content/bulletin/7770 — accessed 2026-07-12
- [3] lni.wa.gov/forms-publications/F627-008-000.pdf — accessed 2026-07-12
- [4] lni.wa.gov/licensing-permits/plumbing/plumber-certification/get-or-renew-your-certification — accessed 2026-07-12