State ladder: apprentice → journeyman → master
Washington State Department of Labor & Industries (L&I) — Plumber Certification Program runs plumbing licensing in Washington. Below: the exact ladder, the transfer doors into Washington from all 50 states, the renewal and lapse lines, and the master-of-record rule for opening a company — every figure from the board's own publications, checked October 22, 2026.
State ladder: apprentice → journeyman → master Primary sources Checked October 22, 2026
| The ladder | Washington |
|---|---|
| Journeyman credential | Journey Level Plumber (PL01) |
| Total hours required | 8,000 |
| Classroom hours | not published |
| Apprentice registration | Required — hours count only while registered |
| Exam | PSI · $202.10 — Exam application fee $202.10 to L&I (the fee is not returned by L&I); exams are administered by PSI and a separate PSI scheduling fee also applies. After passing, L&I invoices the certification fee of $242.70. Failed candidates re-apply and repay the $202.10. L&I revises these fees periodically and older published schedules show lower amounts; the figures here are from L&I's schedule as checked on October 22, 2026. |
| License fee | $242.70 |
| Renewal | Every 3 years (renews on your birthdate; initial certificate runs 25-37 months) |
| Continuing education | 24 hours per 3-year cycle — minimum 12 hours plumbing code and 4 hours industry-related electrical (IRE); the other 8 may be code, IRE or industry-related plumbing |
| Master credential | No master plumber certification in Washington |
| Hour category | Minimum hours |
|---|---|
| Commercial or industrial installations | 4,000 |
Registration, in the board’s terms: You must begin as a Plumber Trainee: trainee certificate from L&I, work under the supervision of a certified journey level plumber, file affidavits of experience, complete 8 hours of approved continuing education each year, and renew the trainee certificate annually ($60 renewal on the L&I trainee page). Out-of-state trainee/apprenticeship hours are not eligible for Washington certification.
No master plumber certification in Washington: Washington has no master level. Journey Level (PL01) is the highest individual plumber certification; the step up is the business-level Plumbing Contractor license with a designated certified plumber (see ownerGate).
Do not look for a Washington 'master plumber' exam or fee — none exists. Specialty levels (Residential PL02, Residential Service PL04, Pump & Irrigation PL03, Domestic Well PL03A, Backflow PL30, Medical Gas MG01 endorsement) sit beside, not above, PL01.
Renewal fee is $242.70; a late renewal (or late CE) doubles it to $485.40 total. 90 calendar days after expiration, an unpaid/un-CE-complete certificate can no longer simply be renewed — the holder must retest to reinstate.
Reinstatement: Within 90 calendar days of expiration: renew late by paying the renewal fee plus an equal late fee ($485.40 total for PL01) and completing the 24 hours of CE.
Past the line: More than 90 days expired without paying the renewal fee and/or completing CE: you must retest to reinstate your certification — a retesting fee of $189.80 applies in addition to the certification fee (L&I Get or Renew page).
Washington endorses journeyman licenses from: Idaho. Idaho ONLY at journey level: email a copy of your active Idaho journey level card and government photo ID to L&I for a reciprocal certificate. All other out-of-state plumbers may present a comparable license (or equivalent U.S. military experience) for consideration but must pass the Washington exam; approved out-of-state licensees may buy a one-time 120-day temporary permit ($100.30) while waiting to test.
| Licensed in | Door into Washington | |
|---|---|---|
| Alabama | No endorsement — exam route | Run the pair → |
| Alaska | No endorsement — exam route | Run the pair → |
| Arizona | No endorsement — exam route | Run the pair → |
| Arkansas | No endorsement — exam route | Run the pair → |
| California | No endorsement — exam route | Run the pair → |
| Colorado | No endorsement — exam route | Run the pair → |
| Connecticut | No endorsement — exam route | Run the pair → |
| Delaware | No endorsement — exam route | Run the pair → |
| District of Columbia | No endorsement — exam route | Run the pair → |
| Florida | No endorsement — exam route | Run the pair → |
| Georgia | No endorsement — exam route | Run the pair → |
| Hawaii | No endorsement — exam route | Run the pair → |
| Idaho | Endorsement available | Run the pair → |
| Illinois | No endorsement — exam route | Run the pair → |
| Indiana | No endorsement — exam route | Run the pair → |
| Iowa | No endorsement — exam route | Run the pair → |
| Kansas | No endorsement — exam route | Run the pair → |
| Kentucky | No endorsement — exam route | Run the pair → |
| Louisiana | No endorsement — exam route | Run the pair → |
| Maine | No endorsement — exam route | Run the pair → |
| Maryland | No endorsement — exam route | Run the pair → |
| Massachusetts | No endorsement — exam route | Run the pair → |
| Michigan | No endorsement — exam route | Run the pair → |
| Minnesota | No endorsement — exam route | Run the pair → |
| Mississippi | No endorsement — exam route | Run the pair → |
| Missouri | No endorsement — exam route | Run the pair → |
| Montana | No endorsement — exam route | Run the pair → |
| Nebraska | No endorsement — exam route | Run the pair → |
| Nevada | No endorsement — exam route | Run the pair → |
| New Hampshire | No endorsement — exam route | Run the pair → |
| New Jersey | No endorsement — exam route | Run the pair → |
| New Mexico | No endorsement — exam route | Run the pair → |
| New York | No endorsement — exam route | Run the pair → |
| North Carolina | No endorsement — exam route | Run the pair → |
| North Dakota | No endorsement — exam route | Run the pair → |
| Ohio | No endorsement — exam route | Run the pair → |
| Oklahoma | No endorsement — exam route | Run the pair → |
| Oregon | No endorsement — exam route | Run the pair → |
| Pennsylvania | No endorsement — exam route | Run the pair → |
| Rhode Island | No endorsement — exam route | Run the pair → |
| South Carolina | No endorsement — exam route | Run the pair → |
| South Dakota | No endorsement — exam route | Run the pair → |
| Tennessee | No endorsement — exam route | Run the pair → |
| Texas | No endorsement — exam route | Run the pair → |
| Utah | No endorsement — exam route | Run the pair → |
| Vermont | No endorsement — exam route | Run the pair → |
| Virginia | No endorsement — exam route | Run the pair → |
| West Virginia | No endorsement — exam route | Run the pair → |
| Wisconsin | No endorsement — exam route | Run the pair → |
| Wyoming | No endorsement — exam route | Run the pair → |
Included in the $49 PlumberLicenseCheck Kit
One payment. Yours to keep. The checkers above stay free either way.
The seat: Designated Certified Plumber — Licensed Plumbing Contractor. A plumbing contractor license (RCW 18.106.400; WAC 296-400A-011) requires the applicant to identify a full-time employee or member of the firm holding a valid journey level (or specialty) certificate as its designated certified plumber, and that plumber's certificate defines the scope of work the contractor may perform. The contractor must also file a $6,000 surety bond (or assigned savings account) and liability insurance, and renew the contractor license every 24 months.
Insurance minimum: $250,000 combined per occurrence general liability insurance (plus $6,000 surety bond)
Only L&I-certified plumbers may legally do plumbing on someone else's property; homeowners may do their own plumbing on property they own. Certification is not required for plumbing systems outside a building (e.g. water/sewer line connections to municipal mains), except domestic pump and pump/irrigation work.
Run the owner gate for your situation →
Rules as published by Washington State Department of Labor & Industries (L&I) — Plumber Certification Program and the statutes it administers, checked October 22, 2026. Board: https://lni.wa.gov/licensing-permits/plumbing/
