Plumbing License Idaho: Requirements, Fees and Why There Is No Master Plumber (2026)

If you search for an Idaho master plumber license, you will find pages that describe one in detail, the requirements, the renewal cycle, the continuing education. None of it is real. Idaho Code 54-2611 lists the plumbing classifications the state actually issues, and the word "master" does not appear anywhere in Title 54, Chapter 26, or in the administrative rules at IDAPA 24.39.20.

That is not a technicality. It is the difference between a tradesperson planning a career around a credential that exists and one planning around a credential that does not. This guide covers what Idaho actually licenses, what it costs, what the exams look like, how to get from apprentice to contractor, what a permit costs, and the one thing that surprises almost every plumbing business owner who wants to run their own company.

At a glance

• Who issues it: Idaho Division of Occupational and Professional Licenses (DOPL), through the Idaho Plumbing Board
• Classifications: six; there is no master plumber
• Journeyman hours: 8,000 hours plus 576 classroom hours, or 16,000 hours with no schooling
• Exam: PSI, $75.00 exam fee; journeyman 100 questions, minimum passing score 70, 180 minutes
• Contractor cost: $22.50 plus $75 plus $147 for three years, plus a $2,000 compliance bond

New to licensing in Idaho? Start with the Idaho contractor license requirements.

Who licenses plumbers in Idaho

The agency is the Idaho Division of Occupational and Professional Licenses (DOPL). The board is the Idaho Plumbing Board, created by Idaho Code 54-2605(1):

"The Idaho plumbing board, referred to as the board, is hereby created and made a part of the division of occupational and professional licenses."

The board has five members, two public members, two plumbing contractors with at least five years of experience each (one of whom must have a gas-piping background), and one journeyman plumber (54-2605(2), (3)).

If a guide tells you the Idaho Division of Building Safety licenses plumbers, that guide is out of date. DBS was folded into DOPL, and the 2023 legislature amended every reference throughout Chapter 26 to read "division of occupational and professional licenses."

Several pages currently ranking for Idaho plumbing terms still name DBS, one of them more than a dozen times. DBS is gone. As of September 2026, one of the top three organic results for "idaho plumbing license requirements" still tells readers that "Licensing for Apprentices, Journeymen, and Plumbing Contractors is managed by the Idaho Division of Building Safety." It is wrong.

The six classifications Idaho actually issues

Idaho Code 54-2611 is exhaustive:

"There shall be three (3) classifications of competency in the business, trade, practice or work of plumbing and three (3) classifications of competency in the business, trade, practice or work of specialty plumbing, as follows: (a) A plumbing contractor... (b) A plumbing journeyman... (c) A plumbing apprentice... (d) A specialty contractor... (e) A specialty journeyman... (f) A specialty apprentice..."

So the ladder is:

• Plumbing Apprentice, registered trainee; may not work unsupervised
• Plumbing Journeyman, the working trade license
• Plumbing Contractor, the business side license; requires the journeyman first
• Specialty Apprentice / Journeyman / Contractor, limited scope, appliance or water pump only

There is no master plumber. The top individual plumbing credential in Idaho is the Plumbing Contractor certificate.

Worth noting for contrast: Idaho does have a master electrician license. DOPL's Electrical Board issues one. So a contractor who moves from the electrical side to the plumbing side, or who reads across trades, can reasonably assume plumbing has the same tier. It does not.

The two specialties that exist

Only two specialty scopes are defined in IDAPA 24.39.20.100.04, and PSI's exam catalog confirms them:

• Appliance Specialty, 3,000 hours of apprentice on the job training plus 72 hours of board approved specialty training, or 6,000 hours of specialty work experience.
• Water Pump Specialty, a minimum of 3,000 hours of specialty related work experience plus the board exam.

Water conditioning is not a specialty license. It is an exemption. Idaho Code 54-2602(1)(g) exempts "Water treatment installations and repairs when installed in residential or business properties," and 54-2602(4) instead requires "a surety bond in the amount of two thousand dollars ($2,000)" from anyone doing that work. Section 54-2604(1)(g) expressly excludes water conditioning equipment from the definition of a plumbing system.

There is also no solar plumbing specialty; "solar systems" appear only inside the rule's definition of a fixture.

Sewer contractors, sewage disposal contractors, and excavating or utility contractors are statutorily exempt from the certificate requirement entirely (54-2602(1)(f)).

Journeyman: the hours, and the two paths

IDAPA 24.39.20.100.02 gives two routes:

"An applicant must pass an examination designated by the Board and either (a) submit evidence of a minimum of eight thousand (8,000) hours of work experience as an apprentice making plumbing installations... and satisfactory completion of 576 hours of a board-approved course of instruction, or (b) submit proof of sixteen thousand (16,000) hours of plumbing experience..."

So: 8,000 hours plus 576 classroom hours, or 16,000 hours with no schooling. The rule adds a restriction most guides omit: "Pipe fitting and appliance plumbing specialty work will not count towards the experience qualifications for a journeyman's certificate of competency."

You must be registered as an apprentice the whole time you are accruing. Idaho Code 54-2614(2) requires an apprentice to "register as an apprentice or a specialty apprentice with the division of occupational and professional licenses and maintain such registration during the entire period in which they are accruing their experience." DOPL's own FAQ puts the consequence plainly: hours worked without being licensed will not count toward the required on the job time. People lose years to this.

There is no apprentice to journeyman ratio in Idaho plumbing law. Neither the statute nor IDAPA 24.39.20 contains a number. The requirement is qualitative, 54-2611(c): "Apprentices shall not perform plumbing work except under the supervision of a journeyman."

Working unsupervised, or employing an apprentice without providing that supervision, is a civil penalty offense under IDAPA 24.39.20.300.05. But if you see a specific ratio published for Idaho plumbing, it was invented.

Plumbing Contractor: the requirement nobody publishes correctly

IDAPA 24.39.20.100.03:

"An applicant must hold a journeyman certificate of competency for a contractor certificate or relevant specialty journeyman certificate for a specialty contractor certificate, successfully pass an examination designated by the Board, and provide a compliance bond in the amount of two thousand dollars ($2,000). Any such bond is required to be effective for the duration of the certificate period..."

Read that carefully. It requires you to hold a journeyman certificate. It does not require you to have held one for any period of time.

There is no time in grade requirement, no 30 months, no two and a half years, no four years as a licensed journeyman. Any page that publishes a multi year licensed journeyman requirement for this credential is describing a rule that does not exist.

The rule also carries a restriction that matters enormously if you are the licensed person in someone else's company:

"A contractor or specialty contractor can only represent one person or entity as stated on an original or renewal license application. In the event the representation changes or ends for any reason, the contractor or specialty contractor must immediately notify the Division in writing. Failure to provide such notification constitutes improper transferring of a license."

One certificate, one company, and the notice duty is immediate, not ten days, not thirty. Idaho does not give plumbing a grace window the way it gives public works contractors a ten day one. The safe posture is same day written notice.

Step by step: how to get licensed

The journeyman path:

1. Register as an apprentice with DOPL before you start accruing hours. Hours worked before you register do not count.
2. Work under a licensed journeyman for 8,000 hours while completing 576 hours of board approved classroom instruction, or accumulate 16,000 hours of plumbing experience with no classroom requirement. Pipe fitting and appliance specialty work do not count toward either path.
3. Once you can show proof of either the 576 classroom hours or the full 16,000 hour path, schedule the Plumbing Journeyman exam through PSI ($75.00 exam fee, paid to PSI, not DOPL).
4. Pass the exam (100 questions, minimum passing score 70, 180 minutes) and submit the DOPL journeyman application with the $22.50 application fee and the $29.40 initial certificate fee.

The contractor path (after journeyman):

1. Hold an active Idaho Plumbing Journeyman certificate. There is no minimum time you must hold it before applying for the contractor exam.
2. Secure a $2,000 compliance bond, effective for the full three year certificate period.
3. Schedule and pass the Plumbing Contractor exam through PSI (100 questions, minimum passing score 75, 240 minutes, $75.00 fee).
4. Submit the DOPL contractor application with the $22.50 application fee, the $147 initial certificate fee, and proof of the bond. Name the single person or entity the certificate represents, and remember the immediate written notice duty if that representation ever changes.

What it costs

Two layers exist and they get confused constantly. The statute sets annual base rates; DOPL bills the three year term amount. Both reconcile exactly.

Statutory rates (Idaho Code 54-2614, 54-2616): application for examination $22.50 for every classification; apprentice registration $50.00 per renewal, specialty apprentice $30.00. Certificate base rates: Plumbing Contractor $75.00 initial / $36.00 renewal; Plumbing Journeyman $15.00 / $7.20.

What DOPL actually charges (dopl.idaho.gov/plb, fee table, retrieved 2026-09-23, page shows last updated August 28, 2026):

Plus a $22.50 application fee on every application.

The arithmetic confirms it: the contractor's $147 is $75 for the first year plus $36 for each of the next two. The $108 renewal is $36 times 3. The journeyman's $29.40 is $15 plus ($7.20 times 2), and $21.60 is $7.20 times 3.

Exam fee: $75.00, paid to PSI, not to DOPL. The PSI Combined Candidate Bulletin (effective December 10, 2025) states the fee is not refundable or transferable and is valid for one year from the date of payment.

Bond: $2,000 for contractors and specialty contractors, effective for the whole certificate period (54-2606(3)(d); IDAPA 24.39.20.100.03). There is no general liability insurance requirement in the plumbing statute or rule; that requirement lives in the separate Contractor Registration Act, covered below. At least one competing guide currently tells readers that licensed plumbing contractors must carry a $300,000 general liability policy. That is not a plumbing certificate requirement: the $300,000 figure belongs to the Contractor Registration Act, and licensed plumbers are exempt from registering under that Act unless they are acting to evade it.

All fees above are set by the board or the testing vendor and are subject to change. Verify current amounts with DOPL and PSI before you budget.

Permit fees and permit rules

A plumbing certificate is not the same thing as a plumbing permit, and the permit side has its own fee schedule that almost no guide covers. IDAPA 24.39.20.500 sets it out in full.

New residential construction (one and two family dwelling units), source IDAPA 24.39.20.500.02.a, retrieved 2026-09-23:

Miscellaneous permit types, source IDAPA 24.39.20.500.02.b and 500.02.c, retrieved 2026-09-23:

Permit mechanics, source IDAPA 24.39.20.500.01, retrieved 2026-09-23: a permit expires 365 days from the purchase date or the last inspection, and with Division approval it can be renewed for one additional year for a $65 renewal fee. A permit can be transferred to another eligible party with written, notarized authorization from the original permit holder, or to the property owner when the owner has ended the relationship with the contractor who pulled it. Either way the Division charges a $45 administrative fee.

Homeowners are exempt from the certificate, not the permit. Idaho Code 54-2602(1)(a) lets an owner do plumbing work on their own single family or duplex dwelling without a certificate, but a homeowner making plumbing installations on their own premises must still secure a plumbing permit from the Division under Idaho Code 54-2602(1)(a) and 54-2620. DOPL's FAQ limits the homeowner permit to primary and secondary residences and related outbuildings; it does not cover commercial property. Business owners sometimes assume an owner will simply pull their own permit and skip a licensed plumber entirely; the permit requirement does not disappear just because the person doing the work owns the building.

The exam

Vendor: PSI. Content: IAPMO. DOPL's licensing page directs applicants to register for and pass the IAPMO examination through PSI before submitting the DOPL application, and the application form asks the question directly.

From the PSI Combined Candidate Bulletin, effective December 10, 2025:

Note that the passing score is not uniform: 70 for the journeyman, 75 for the contractor and every specialty exam.

The contractor exam is a hybrid, roughly 40 code and sizing items drawn from the 2017 Idaho State Plumbing Code, and 60 items from DOPL's Contractor's Business and Law Reference Manual. The journeyman exam is code only, chapter weighted across the ISPC, including two pipe sizing questions scored at four points each.

Both are open book. The allowed references for the contractor exam are the DOPL Contractor's Business and Law Reference Manual, the 2015 Uniform Plumbing Code, and the 2017 Idaho State Plumbing Code.

On retakes, Idaho Code 54-2614(2): a candidate who fails may reapply at the next scheduled examination on payment of the fee, but "Should any person fail to pass the examination the second time, the board may refuse to allow a subsequent examination until the expiration of one (1) year."

Idaho uses the UPC, not the IPC

IDAPA 24.39.20.600: "Pursuant to Section 54-2601, Idaho Code, the Board adopts, as the Idaho State Plumbing Code (ISPC), the 2015 Uniform Plumbing Code, including Appendices A, B, C, D, E, G, I, J, K and L," with fifty numbered Idaho amendments. Section 54-2601(1) requires accord with the code published by the International Association of Plumbing and Mechanical Officials.

Any page telling you to study the International Plumbing Code for an Idaho plumbing exam has the wrong code family. Among the notable Idaho amendments: a 42 inch minimum cover on building supply yard piping, a mandatory pre-plumbed water softener loop in new slab-on-grade and finished-basement one and two family dwellings, sidewall venting permitted, and air admittance valves allowed only in residential settings and never in bathroom groups.

Continuing education: there is none

DOPL's plumbing FAQ, page updated May 27, 2026, answers it directly: "There are no Continuing Education Requirements (CEU) for plumbing."

This is a genuine trap, because the statute makes it look otherwise. Idaho Code 54-2617(2) says a certificate may be renewed "by providing proof of completion of the continuing education requirements as established by the board," and 54-2606(3)(c) authorizes the board to set them. But the board has never established any. IDAPA 24.39.20 as currently in force contains no continuing education section at all, and the Plumbing Board did not engage in rulemaking during the 2025 to 2026 session.

The correct statement is: Idaho currently requires zero continuing education hours for plumbing journeymen and contractors. The board retains authority to impose CE and has not used it. If you see a specific continuing education hour count published for Idaho plumbing, it does not match DOPL's own FAQ, and it does not match anything in IDAPA 24.39.20.

Renewal and expiry

Idaho Code 54-2617:

"(1) Certificates of competency shall be issued for a period of three (3) years and shall expire three (3) years from the date of issue... (2) A certificate of competency for plumbing contractor or journeyman may be renewed at any time during the month prior to its expiration... (3) Failure of any holder to timely renew a certificate of competency shall cause lapse of the certificate, but it may be revived within two (2) years without examination only upon payment of the full initial fee."

Three years, not two, and not annual. Multiple competing pages publish a "biennial cycle" or an annual renewal. The statute and the DOPL fee table both say three years for journeyman and contractor certificates.

There is no fixed statewide renewal date; renewal keys to your individual issue date. Apprentice registration runs five years; specialty apprentice registration runs three, and a lapsed apprentice registration may be revived within one year on payment of the renewal fee (54-2614A).

On the death or incapacity of a contractor, 54-2617(5) allows a temporary contractor certificate to issue to a holder of an active Idaho journeyman certificate, valid for ninety days and renewable once, but the temporary holder may not pull new permits or solicit new work.

Reciprocity from other states

DOPL's plumbing FAQ answers yes, Idaho has reciprocal licensing agreements, and points to a separate "Reciprocal Information" document for the list; as of September 2026 that linked document does not load. DOPL's own site does host journeyman plumber reciprocity agreements with Montana, Oregon and Washington. Each one covers the journeyman certificate only, and each requires an application in the state you are moving to plus documented experience that meets that state's requirements.

These agreements are older documents, so before you plan around one, contact DOPL directly (208-334-3233) and confirm it is still in force for your situation. Do not rely on a third party guide's list of reciprocal states; ask the board.

Penalties

Unlicensed plumbing is a misdemeanor under 54-2628, punishable by a fine of not less than $10 and not more than $300, up to thirty days in county jail, or both. On top of that sit civil penalties of up to $1,000 per count (54-2606(3)(f); IDAPA 24.39.20.300). Advertising as a plumbing contractor without a certificate, or advertising without your certificate number in the ad, is its own listed civil penalty offense under IDAPA 24.39.20.300.09.

New for 2026: the 48-hour inspection rule

House Bill 585, signed March 31, 2026 and effective July 1, 2026 under an emergency clause, added a new Idaho Code 54-2626A. It is short and it is useful:

"If an inspection requested by a permit holder is not performed within forty-eight (48) business hours, such permit holder shall be authorized to hire a third-party inspector to perform such inspection."

You notify DOPL or the local government, you provide a copy of the results, and you are refunded the inspection fee you already paid. There is a second provision most people miss: if an inspector fails your work and does not give you a reason within three business days, the division or local government must refund ten percent of the inspection fee.

Parallel sections were added for electrical (54-1004A) and HVAC (54-5020A) in the same bill. If you run a plumbing business in Idaho, this changed your schedule risk on July 1 and almost nobody in the licensing guide space has covered it.

The part that catches business owners: registration is separate

Your plumbing contractor certificate lets you do plumbing work. It is not the only thing Idaho asks of a construction business.

The Idaho Contractor Registration Act (Title 54, Chapter 52) requires registration; DOPL states plainly that "The Act requires registration, not licensure." There is no exam and no bond, but 54-5210(1)(e) requires proof of general liability coverage "in the sum of not less than three hundred thousand dollars ($300,000) single limit," plus workers' compensation coverage or a statement of why it is not required.

Helpfully, 54-5205(1) exempts anyone already licensed under Chapter 26 (plumbing), Chapter 50 (HVAC), Chapter 10 (electrical) and several others, "so long as such person is not acting with the intent to evade this chapter. No such person exempt hereunder may hold himself out as a registered contractor."

The teeth are worth knowing anyway, because they apply to the general contractors you work for. Section 54-5217(2): an unregistered contractor may not "bring or maintain any action in any court of this state for the collection of compensation." Section 54-5208 goes further; an unregistered contractor "shall be deemed to have conclusively waived any right to place a lien upon real property."

Idaho has no statewide general contractor license. The only construction credential with an exam is the Public Works Contractor License, and it applies only to publicly funded projects, a distinction we cover in the Idaho public works qualified individual guide. If you are trying to sort out which credential your business actually needs, our guide to state vs. local contractor licensing and contractor license vs. business license covers the general framework, and our contractor license pillar page walks through how state licensing works across the country.

Where the qualifier question comes in

Idaho Code 54-2610 is the provision that turns a personal credential into a business asset:

"It shall be unlawful for any person or firm, copartnership, association or corporation, to engage in the business, trade, practice or work of plumbing in this state... unless such person, or responsible person representing such firm, copartnership, association or corporation, has successfully passed an examination as provided herein and has issued to him a state certificate of competency, which shall not be transferable."

That "responsible person representing such firm" is Idaho's plumbing qualifier, in all but name. A company cannot hold plumbing work on its own. A licensed individual has to stand behind it, and the certificate follows that individual; it does not belong to the company and it cannot be transferred.

Section 54-2611(a) reinforces it: "A contractor who in person does plumbing work shall also be qualified as a journeyman plumber, or have in his employ on all work a qualified journeyman." Section 54-2611(b) defines the journeyman as someone "who works in the employ and under the direction of a plumbing contractor." Idaho's structure assumes an employment relationship throughout.

That is the situation The Licensing Company exists for. When a plumbing business needs a certificate holder and does not have one in house, because the owner has not tested, because the licensed person left, or because the company is expanding into Idaho from another state, we place a qualifying agent as a full time W-2 employee of the business who actually supervises the work. Not a percentage arrangement, not a flat fee per project, not a 1099 consultant whose name sits on a license he has no real connection to. Idaho's own agency draws the same line: DOPL's public works fact sheet tells licensed contractors that if they take on an unlicensed contractor's crew, "you must pay the employees directly and provide them with a form W-2."

If your certificate holder just gave notice, the contractor qualifier contingency plan walks through the deadlines state by state. If you are weighing whether the licensed person has to be an owner, our owner-vs-employee guide covers what states actually require. Idaho ties each contractor certificate to one person or entity at a time, and IDAPA 24.39.20.100.03.a treats a failure to give the Division immediate written notice when that representation changes as "improper transferring of a license." The safe structure is a certificate holder who is a full time W-2 employee and actually supervises the work; our guide on what the law allows explains why.

Frequently asked questions

Does Idaho have a master plumber license? No. Idaho Code 54-2611 lists six classifications, plumbing contractor, journeyman and apprentice, plus specialty contractor, journeyman and apprentice, and none of them is a master. The word "master" does not appear in Title 54, Chapter 26 or in IDAPA 24.39.20.

The highest individual plumbing credential is the Plumbing Contractor certificate. Idaho does issue a master electrician license, which is probably where the confusion started.

How much does an Idaho plumbing license cost? For a journeyman: $22.50 application plus $75 PSI exam fee plus $29.40 for a three year certificate. For a contractor: $22.50 plus $75 plus $147 for three years, plus a $2,000 compliance bond. Renewals are $21.60 and $108 respectively. These are set by the board and PSI and change; verify before budgeting.

How long does an Idaho plumbing license last? Three years from the date of issue (54-2617(1)). Not two, and not annual. A lapsed certificate can be revived within two years without re-examination by paying the full initial fee.

Does Idaho require continuing education for plumbers? No. DOPL states there are no continuing education requirements for plumbing. The statute authorizes the board to set them; the board never has.

Do I need a journeyman license before the contractor license? Yes, but with no waiting period. IDAPA 24.39.20.100.03 requires you to hold a journeyman certificate, pass the contractor exam, and post a $2,000 bond. There is no minimum time as a journeyman first.

Does Idaho charge plumbing permit fees based on square footage? Yes, for new one and two family residential construction. IDAPA 24.39.20.500.02.a sets a tiered fee schedule from $130 for up to 1,500 square feet to $325 plus $65 per additional 1,000 square feet over 4,500 square feet. Existing residential inspections, technical service calls, and commercial or multifamily work are billed under separate schedules in the same rule.

How much does it cost to hire a qualifying agent in Idaho? There is no published rate, and any site quoting one is guessing. What it costs depends on the classification, whether the business already has licensed people on staff, the scope and risk of the work, how many licenses the arrangement has to support, and how quickly you need someone seated. It is quoted per situation. If you want a real number for yours, start with a consultation and we will scope it against your actual work.

Can a plumbing certificate holder qualify more than one company in Idaho? No. IDAPA 24.39.20.100.03.a limits a contractor or specialty contractor to representing "one person or entity as stated on an original or renewal license application," and requires immediate written notice to DOPL when that representation changes.

Sources

• Idaho Division of Occupational and Professional Licenses, State Plumbing Board (retrieved 2026-09-23, page shows last updated August 28, 2026)
• DOPL Plumbing FAQs (retrieved 2026-09-23, page shows last updated May 27, 2026)
• IDAPA 24.39.20, Rules Governing Plumbing, current rule (effective 3-28-23) (retrieved 2026-09-23)
• Idaho Code Title 54, Chapter 26, Plumbing and Plumbers (retrieved 2026-09-23)
• Idaho Code 54-2611, Classification of Competency (retrieved 2026-09-23)
• PSI Combined Candidate Bulletin, effective 12.10.2025 (retrieved 2026-09-23)
• DOPL Plumbing, Apply for or Renew a License (retrieved 2026-09-23)
• DOPL Plumbing, Statutes, Rules and Guidance (rulemaking status) (retrieved 2026-09-23)
• DOPL journeyman plumber reciprocity agreements: Montana, Oregon, Washington (retrieved 2026-09-23)
• Idaho Code 54-2626A (retrieved 2026-09-23)
• House Bill 585 (2026 session), creating Idaho Code 54-2626A (retrieved 2026-09-23)
• Idaho Contractor Registration Act, Title 54, Chapter 52 (retrieved 2026-09-23)

Fees, exam specifications and code editions cited here are set by the Idaho Division of Occupational and Professional Licenses, the Idaho Plumbing Board and PSI, and are subject to change. Verify current requirements with DOPL and PSI before applying. Statutes and rules current as of September 2026.

If you need a licensed plumbing certificate holder to stand behind your Idaho business, see how qualifying agent placement works, or if you hold an Idaho plumbing contractor certificate and want to put it to work, look at becoming a qualifying agent. You can also call 615-219-2110 to talk through your situation directly.