Construction / Plumber License / Idaho
- Idaho
- Plumber License
- Journeyman & Contractor
- Updated Oct 2026
How to Get Your Idaho Plumber License
How to qualify for an Idaho journeyman plumber certificate or plumbing contractor license, what’s on the open-book exams, and where reciprocity applies.
Last updated October 27, 2026 from Idaho Division of Building Safety requirements
Application fee
$22.50
Plus $75 PSI exam fee and a license fee
Exam time
3–4 hrs
4 hrs journeyman, 3 hrs contractor
Time to get license
~4 yrs
Journeyman; contractor adds 2.5 yrs
Continuing ed
Not stated
Confirm with DBS
Overview
Do you need an Idaho plumber license?
Yes. In Idaho, anyone who does the physical work of installing or altering plumbing needs a journeyman certificate, and anyone who offers plumbing contracting services, including submitting a bid, needs a plumbing contractor license.
License required when
- You install, improve, extend or alter plumbing systems (journeyman)
- You supervise that work under a plumbing contractor (journeyman)
- You offer or provide plumbing contracting services, including submitting a bid (contractor)
Common exceptions
- Our source notes don’t list exemptions, so check the Idaho Plumbing Statutes and Rules
- Journeymen work under the direction of a plumbing contractor rather than contracting on their own
Penalties for unlicensed work
The Division of Building Safety enforces Idaho’s plumbing licensing law and can take action against people who work or bid without the right license. Check the Idaho Plumbing Statutes and Rules for details.
Your fast-track Idaho plumber license checklist
The Idaho application, one page
- Proof of a Board-approved 4-year course
- 8,000 hours of supervised experience
- Approved exam application
- Passing journeyman score (75%)
- 2.5 years as a licensed journeyman (contractor)
- Passing Plumbing Contractor exam (contractor)
Types
Idaho plumber license types and classifications
Idaho has two plumbing tiers. You start as a journeyman, then can move up to plumbing contractor after 2.5 years licensed.
JRY
Start here
Journeyman Plumber
Performs or supervises the physical work of installing, improving, extending or altering plumbing under the direction of a plumbing contractor.
Exam
4 hrs, open book
Limit
Under a contractor
PC
Can bid
Plumbing Contractor
Provides or offers plumbing contracting services, including submitting bids.
Exam
3 hrs, open book
Limit
Not stated
Requirements
Idaho plumber license requirements, class by class
The journeyman route is about training and hours. The contractor route builds on an active journeyman certificate.
| Requirement | Journeyman | Plumbing Contractor |
|---|---|---|
| Experience | 4 years (8,000 hours) under constant on-the-job supervision | 2.5 years as a licensed journeyman |
| Training | Board-approved 4-year course of instruction | Not stated |
| Prerequisite license | None | Active journeyman plumbing certificate |
| Exam | Idaho Plumbing Journeyman exam | Idaho Plumbing Contractor exam |
| Exam approval | Required | Required |
| Passing score | 75% | Not stated |
Steps
How to get your Idaho plumber license, step by step
- Complete training and hours~4 years
Finish a Board-approved 4-year course of instruction and at least 8,000 hours of supervised on-the-job work. - Apply for exam approvalBefore you test
Submit your application with proof of your training and experience. Call DBS at 208-332-7137 to begin the exam process. - Pass the journeyman examExam day
4 hours, open book, 75% to pass. Bring your tabbed and highlighted references. - Get your journeyman certificateAfter you pass
Apply through the Division of Building Safety for your certificate. - Work 2.5 years as a journeymanContractor route
Log at least 2.5 years as a licensed journeyman in a recognized jurisdiction. - Pass the contractor exam3-hour exam
Apply for approval, then sit the open-book Plumbing Contractor exam and apply through DBS for your contractor license.
Exam
What to expect on the Idaho plumber exam
Both Idaho plumbing exams are open book. You can tab and highlight the approved references and use them during the test.
Format
Open book
Questions
Not stated
Passing score
75% (JRY)
Exam vendor
PSI
Scoring & content
- Journeyman: 4 hours, 75% to pass
- Journeyman topics: code chapters 1–12 and appendix, sizing, statutes and rules, math, contractor business and law
- Contractor: 3 hours; topics include code chapters 5–12, sizing, statutes and rules, business and law
- References include the Uniform Plumbing Code, the DBS Contractor’s Business and Law Reference Manual and the Idaho Plumbing Statutes and Rules
- Tabbing and highlighting your references is allowed
Retake policy
- Retake rules aren’t stated in our sources
- State approval is required before you schedule
- Each attempt needs a new $75 exam fee
Exam references · Open book
Idaho’s plumbing exams are open book, and the references can be tabbed, highlighted and used during the test. The list covers both the Journeyman Plumbing and Plumbing Contractor exams.
| Book | Edition | Use |
|---|---|---|
| Uniform Plumbing Code (UPC) | 2015 | Allowed in exam |
| Idaho Plumbing Statutes and Rules | Not stated | Allowed in exam |
| Contractor’s Business and Law Reference Manual (Idaho Division of Building Safety) | Not stated | Allowed in exam |
Prep
Best Idaho plumber exam prep, compared
We haven’t compared prep courses for this exam yet.
Costs
How much does an Idaho plumber license cost?
| Item | Type | Estimate |
|---|---|---|
| Application fee | Fixed | $22.50 |
| Exam fee (PSI, per attempt) | Fixed | $75 |
| Initial license fee | Fixed | $29.40 journeyman, $147 contractor |
| Uniform Plumbing Code book | Variable | Varies |
| DBS reference manual and statutes | Fixed | Free online |
| State fees and exams | Journeyman: application, one exam attempt and license fee; excludes code book | $126.90 |
Fees from the Idaho DOPL Plumbing Board fee table and the PSI Idaho candidate bulletin, checked October 2026.
Reciprocity
Does Idaho accept out-of-state plumber licenses?
Idaho journeyman plumbers have reciprocity agreements with three states. Our sources don’t say exactly what’s waived, so confirm the details with DBS.
Montana — journeyman reciprocity
Covers journeyman plumbers. Contact DBS for current terms.
Oregon — journeyman reciprocity
Covers journeyman plumbers. Contact DBS for current terms.
Washington — journeyman reciprocity
Covers journeyman plumbers. Contact DBS for current terms.
Local
Do Idaho cities and counties have their own plumber licensing rules?
Plumbing licenses come from the state, but local jurisdictions still handle permits and inspections on many jobs.
State handles
- Journeyman certificates and contractor licenses
- Exam approval
- Plumbing statutes and rules
- Enforcement and discipline
City & county handle
- Plumbing permits where the jurisdiction runs its own program
- Inspections
- Local business licenses
Governance
Who regulates plumbers in Idaho
Oversight responsibilities
- Issues journeyman certificates and plumbing contractor licenses
- Approves applicants to sit for exams
- Publishes the Idaho Plumbing Statutes and Rules
- Enforces plumbing licensing law
Maintenance
How to renew your Idaho plumber license and keep it active
Journeyman and contractor plumbing licenses run 3 years. Renewal costs $21.60 for a journeyman and $108 for a contractor. Our sources don’t state continuing education rules for plumbers, so check with DOPL before your license expires.
Renewal cycle
3 years
CE hours
Not stated
Renewal fee
$21.60 (journeyman); $108 (contractor)
Late penalty
Not stated
Renewing your license?
See the Idaho CE guide: hours, deadline, required topics and how to renew.
FAQ
Idaho plumber license FAQs
How long does it take to become a journeyman plumber in Idaho?
About 4 years. You need a Board-approved 4-year course of instruction and at least 8,000 hours of supervised work experience.
Is the Idaho plumbing exam open book?
Yes. You can tab, highlight and use the approved references during both the journeyman and contractor exams.
What score do I need to pass the journeyman exam?
75% correct, within the 4-hour time limit.
How do I become a plumbing contractor in Idaho?
Hold an active journeyman certificate, log at least 2.5 years as a licensed journeyman, and pass the 3-hour Plumbing Contractor exam.
Does Idaho have plumbing reciprocity?
Yes, for journeyman plumbers with Montana, Oregon and Washington. Confirm the terms with DBS.
Who issues plumbing licenses in Idaho?
The Idaho Division of Building Safety.
Sources
Official sources for the Idaho plumber license
- Idaho Division of Building Safety, Plumbing program
- DBS Contractor’s Business and Law Reference Manual (PDF)
- Idaho Plumbing Statutes and Rules (PDF)
- Uniform Plumbing Code
- Idaho DOPL, Plumbing Board license fees
- PSI, Idaho DOPL Candidate Information Bulletin (effective 7/9/2026)
Last updated October 27, 2026. Spot something out of date? Tell us.
Exam Insiders is an independent guide and is not affiliated with the Idaho Division of Building Safety.