How to Become a Plumber in Idaho

The Idaho Licensing Ladder: Apprentice, Journeyman, Contractor

Idaho structures its plumbing trade into three active license tiers managed by the Division of Occupational and Professional Licenses (DOPL). There is no separate "master plumber" license — the Plumbing Contractor credential is the functional equivalent and the highest tier in the state.

The path from zero experience to licensed contractor takes a minimum of 6.5 years, and that timeline assumes you take the faster schooling route. Here's how each tier works.

Step 1: Register as a Plumbing Apprentice

Before you touch a single pipe for pay, you need an active apprentice registration from DOPL. This is non-negotiable — any hours worked before your card is active are legally void and will not count toward your experience total.

Requirements are straightforward:

• Minimum age of 16
• No prior experience or exam required
• $22.50 application fee plus $50 registration fee
• Registration is valid for five years

Once registered, you must work under the direct supervision of a licensed journeyman at all times. Your employer must hold an active plumbing contractor license.

Step 2: Accumulate Experience Through One of Two Pathways

Idaho offers two routes to qualify for the journeyman exam:

The Schooling Pathway (4 years minimum): Complete 8,000 hours of on-the-job training alongside a four-year technical education program at a state-approved college. The schools — North Idaho College, College of Western Idaho, College of Southern Idaho, Lewis Clark State College, College of Eastern Idaho, and Idaho State University — require 144 classroom hours per year (576 total). Courses must be completed sequentially, and you need a minimum 70% grade average.

The Work-Only Pathway (8 years minimum): If you skip formal schooling, you need 16,000 hours of supervised on-the-job training while maintaining continuous active registration. That's roughly eight years of full-time work.

The schooling pathway is twice as fast. For most people, the tuition investment (around $1,950 per year at North Idaho College, with Idaho Launch scholarship eligibility) pays for itself in the four years of additional journeyman wages you'd otherwise miss.

Step 3: Pass the Journeyman Exam

Here's where Idaho's sequencing catches people off guard — you must pass the trade exam through PSI Services before submitting your license application to DOPL. Do not submit the license application until you have the passing score report.

The journeyman exam is open-book, computer-based, a 100-point exam in 3 hours. You can bring physical copies of the 2015 Uniform Plumbing Code and the 2017 Idaho State Plumbing Code with permanent tabs and highlighting (no handwritten notes or sticky notes). The passing score is 70%, and the exam costs $75 per attempt with unlimited retakes.

After passing, submit your application through the DOPL portal at edopl.idaho.gov with your score report, work verification forms, and school certificate of completion. The initial license fee is $29.40, and your digital license typically arrives within one business day.

Step 4: Advance to Plumbing Contractor

A journeyman license lets you perform independent plumbing work, but you can't pull permits, hire employees, or run your own business without upgrading to a Plumbing Contractor license. That upgrade requires:

• An active Idaho journeyman license with at least 30 months (2.5 years) of post-licensure experience
• Passing the contractor exam through PSI (4 hours, focused on business law and contractor regulations, $75 fee)
• A $2,000 surety compliance bond
• General liability insurance with a minimum $300,000 coverage
• $22.50 application fee plus $147 initial license fee

The contractor exam is also open-book — you'll need DOPL's Contractors' Business and Law Reference Manual printed and placed in a three-ring binder.

Timeline and Cost Summary

The fastest path from apprentice registration to contractor license takes about 6.5 years:

• Years 1–4: Apprenticeship with schooling (8,000 OJT hours + 576 classroom hours)
• Year 4–5: Pass journeyman exam, obtain journeyman license
• Years 5–6.5: Accumulate 30 months of journeyman experience
• Year 6.5: Pass contractor exam, obtain contractor license

Total application and initial license fees along that path run roughly $294, not counting exam fees ($150 for both exams assuming first-attempt passes), school tuition, or insurance and bonding costs.

If you're planning your route through the Idaho plumbing licensing process, the Idaho Plumber License Guide breaks down every step with filing checklists, work verification templates, and a decision tree for choosing between pathways.

See more Idaho guides →