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 guides describing one in detail, complete with a renewal cycle and continuing education hours. None of it is real. Idaho Code 54-2611 lists six 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 gap matters for anyone planning a career or a business around Idaho plumbing licensing. This guide covers what Idaho actually licenses, what it costs, what the PSI exams look like, how to move from apprentice to contractor, what a permit costs, and the one requirement that catches most plumbing business owners off guard.

At a glance

• Who issues it: Idaho Division of Occupational and Professional Licenses (DOPL), through the Idaho Plumbing Board
• Classifications: six total; 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 fee; journeyman exam runs 100 questions, 70 minimum passing score, 180 minutes
• Contractor cost: $22.50 application plus $75 exam fee plus $147 for a three year certificate, plus a $2,000 compliance bond

New to Idaho licensing generally? Start with our Idaho contractor license requirements guide, or see how state licensing works across the country on our contractor license pillar page.

Who licenses plumbers in Idaho

The agency is the Idaho Division of Occupational and Professional Licenses, known as DOPL. The board is the Idaho Plumbing Board, created by Idaho Code 54-2605. It seats five members: two from the public, two plumbing contractors with at least five years of experience each (one with a gas piping background), and one journeyman plumber.

If a guide tells you the Idaho Division of Building Safety licenses plumbers, that guide is out of date.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. DOPL's own plumbing pages, checked again on 2026-10-15, make no mention of DBS anywhere. Pages still naming DBS as the licensing body are describing an agency that no longer exists.

The Board's powers run beyond issuing certificates. Idaho Code 54-2606 lets it set examination content, discipline license holders, and recommend fee amounts within the statutory ranges, while the Division administrator under 54-2607 handles day to day licensing, permitting and inspection operations. In practice, that split is why fee questions go to the Division's online portal while rule and discipline questions route through the Board.

The six classifications Idaho issues, and the one it does not

Idaho Code 54-2611 sets three classifications in plumbing and three parallel classifications in specialty plumbing:

• Plumbing Apprentice, a registered trainee who may not work unsupervised
• Plumbing Journeyman, the working trade license
• Plumbing Contractor, the business side license, which requires the journeyman certificate first
• Specialty Apprentice, Specialty Journeyman and Specialty Contractor, limited to appliance or water pump work

There is no master plumber. The top individual plumbing credential in Idaho is the Plumbing Contractor certificate. For contrast, Idaho does issue a master electrician license through DOPL's Electrical Board, which is likely where the confusion starts for anyone reading across trades.

Only two specialty scopes exist

IDAPA 24.39.20.100.04 and PSI's exam catalog both confirm only two specialty paths:

• 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 with no classroom requirement
• Water Pump Specialty: a minimum of 3,000 hours of specialty related work experience, plus the board exam

Each specialty scope is narrow. An Appliance Specialty certificate covers disconnecting, capping, removing and reinstalling a water heating appliance, water treating or filtering devices, potable water air or space temperature equipment, a humidifier, temperature and pressure relief valves, and condensate or indirect drains, within 60 inches of the original location, in one and two family homes only. It does not cover installing or certifying backflow devices or touching the drain, waste or vent system. A Water Pump Specialty certificate covers only installing and connecting water service piping from the pump to the storage expansion pressure tank, again in one and two family homes only, and also excludes backflow device work.

Water conditioning is not a specialty license; it is an exemption. Idaho Code 54-2602(1)(g) exempts water treatment installations and repairs on residential or business property, and 54-2602(4) requires a $2,000 surety bond instead from anyone doing that work. Idaho Code 54-2604(1)(g) separately excludes water conditioning equipment from the statutory definition of a plumbing system. There is also no solar plumbing specialty; solar systems appear only inside the rule's definition of a fixture, at IDAPA 24.39.20.002.01.

Who is exempt from the certificate entirely

Idaho Code 54-2602 carves out more exceptions than most guides cover, and missing one can mean assuming a credential is required when it is not, or the reverse:

• Owners or contract purchasers doing plumbing in their own single family or duplex home and its accessory structures
• Farm buildings outside city limits, unless connected to public water or sewer, with living and public spaces excluded from the exception
• Sewer, septic, excavating and utility contractors working outside a building's foundation
• Businesses with their own in house maintenance or construction plumbers doing work on their own premises, though new construction and alterations still must meet code
• Licensed HVAC and electrical contractors doing limited, overlapping work: certain water heater wiring, gas and hydronic piping, and specified boiler work
• Nonprofit home builders with 501(c)(3) status, including religious corporations, building single family homes with volunteer labor, provided they name a primary contact for inspectors
• High school students in a board recognized program, who may do supervised residential plumbing work without apprentice registration, though those hours do not count toward journeyman experience

None of these exceptions removes the permit requirement for the work itself; most only remove the certificate requirement for the person doing it.

Journeyman: the hours, and the two paths

IDAPA 24.39.20.100.02 gives two routes to the journeyman exam: 8,000 hours of apprentice work experience plus 576 hours of board approved classroom instruction, or 16,000 hours of plumbing experience with no classroom requirement. Pipe fitting and appliance specialty work do not count toward either path.

You must be registered as an apprentice for the entire period you are accruing hours. Idaho Code 54-2614(2) requires apprentice registration to run concurrently with the experience being claimed, and DOPL's own FAQ states plainly that hours worked without being licensed will not count toward the required on the job time. People lose years to this rule.

There is no apprentice to journeyman ratio in Idaho plumbing law. Neither the statute nor IDAPA 24.39.20 sets a number; the requirement is qualitative. Idaho Code 54-2611(c) states that apprentices may not perform plumbing work except under journeyman supervision, and working unsupervised is a civil penalty offense under IDAPA 24.39.20.300.05. 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 requires an applicant to hold a journeyman certificate, pass the board designated exam, and provide a $2,000 compliance bond effective for the full certificate period. Read closely: it requires holding a journeyman certificate, not holding one for any minimum length 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 publishing a multi year journeyman requirement for the Idaho contractor certificate is describing a rule that does not exist here.

The rule also restricts how a contractor certificate can be used. A contractor or specialty contractor may represent only one person or entity at a time on an original or renewal application. If that representation changes or ends, the certificate holder must notify the Division in writing immediately; failure to do so is treated as improper transferring of a license. Idaho gives this notice duty no grace window at all, unlike the ten day window it gives public works contractors.

Step by step: how to get licensed

The journeyman path:

1. Register as an apprentice with DOPL before accruing any hours. Hours worked before registration 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 the classroom hours or the full 16,000 hour path, schedule the Plumbing Journeyman exam through PSI for a $75.00 fee paid directly 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, naming the single person or entity the certificate represents.

What it costs

Two fee layers exist and they get confused constantly. The statute sets annual base rates; DOPL bills the three year term amount, and the two reconcile exactly. The contractor's $147 is $75 for the first year plus $36 for each of the next two; the $108 renewal is $36 times three. The journeyman's $29.40 is $15 plus two payments of $7.20, and the $21.60 renewal is $7.20 times three.

What DOPL currently charges, from the live fee table checked 2026-10-15 (page shows last updated August 28, 2026):

Add a $22.50 application fee on every application, and a $75.00 exam fee paid to PSI, not refundable or transferable, valid for one year from payment.

The $2,000 compliance bond applies to contractors and specialty contractors for the whole certificate period. There is no general liability insurance requirement inside the plumbing statute or rule; that requirement lives in the separate Contractor Registration Act, covered below. If a competing guide tells you licensed plumbing contractors must carry a $300,000 general liability policy, that 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 under IDAPA 24.39.20.500 that few guides cover in full.

New one and two family residential construction, source IDAPA 24.39.20.500.02.a:

*Over 4,500 square feet: $325 plus $65 for each additional 1,000 square feet or portion thereof.

Other permit types, source IDAPA 24.39.20.500.02.b and 500.02.c:

Notes on the table above:

• The cost based tier covers multifamily, industrial and commercial work, plus nonresidential sewer or water lines, nonresidential sprinklers, reclaimed water systems, and mobile home or RV parks. Up to $10,000 of plumbing system cost is $60 plus 2 percent; $10,000 to $100,000 is $260 plus 1 percent of the amount over $10,000; over $100,000 is $1,160 plus 0.5 percent of the amount over $100,000.
• A $65 per hour additional fee applies to repeat inspection trips caused by the permit holder, including work that is not ready, a wrong location, no site access, or uncorrected items from a prior notice.

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

Inspections happen in stages, each marked with its own tag. A ground work tag covers work before it is buried, typically attached to a vertical riser. A rough-in tag covers the system before it is covered or concealed. A final tag confirms the completed work matches the permit and the code. If the installation is not acceptable, the inspector attaches a notice of correction tag instead, and a paid reinspection follows once the corrections are made.

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 that same owner must still secure a plumbing permit 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.

The exam

The vendor is PSI; the content comes from IAPMO. DOPL directs applicants to register for and pass the IAPMO examination through PSI before submitting the DOPL application.

From the PSI Combined Candidate Bulletin, effective 12.10.2025:

The passing score is not uniform: 70 for the journeyman exam, 75 for the contractor exam and every specialty exam. The contractor exam blends roughly 40 code and sizing items from the 2017 Idaho State Plumbing Code with 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 worth four points each.

Both exams are open book. The contractor exam allows the DOPL Contractor's Business and Law Reference Manual, the 2015 Uniform Plumbing Code, and the 2017 Idaho State Plumbing Code; the journeyman exam allows the 2015 UPC and 2017 ISPC. On retakes, Idaho Code 54-2614(2) lets a candidate reapply at the next scheduled exam on payment of the fee, but after a second failure the board may bar a retake until a full year has passed.

Idaho uses the UPC, not the IPC

IDAPA 24.39.20.600 adopts the 2015 Uniform Plumbing Code, including Appendices A, B, C, D, E, G, I, J, K and L, as the Idaho State Plumbing Code, with fifty numbered Idaho amendments. A page telling you to study the International Plumbing Code for an Idaho exam has the wrong code family. Notable amendments include 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 homes, permitted sidewall venting, and air admittance valves allowed only in residential settings and never inside bathroom groups. The amendments also change two fixture unit values from national defaults: bathtubs, combination bath and shower units, and clothes washers each count as two fixture units rather than the unmodified code value, which affects drain and vent sizing calculations on the exam and in the field.

Continuing education: there is none

DOPL's plumbing FAQ, last updated May 27, 2026, answers this directly: there are no continuing education requirements 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 on proof of completing 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 contains no continuing education section at all.

The correct statement: Idaho currently requires zero continuing education hours for plumbing journeymen and contractors. The board retains authority to impose CE and has not used it. Any specific CE hour count published for Idaho plumbing matches neither DOPL's FAQ nor IDAPA 24.39.20.

Renewal and expiry

Idaho Code 54-2617(1) sets a three year certificate term from the date of issue. Certificates may be renewed during the month before expiration. A holder who fails to renew on time lets the certificate lapse, but it can be revived within two years without a new exam by paying the full initial fee.

Three years, not two, and not annual. Multiple competing pages publish a biennial or annual cycle for Idaho plumbing; both the statute and the live DOPL fee table 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 can be revived within one year on payment of the renewal fee.

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

Reciprocity from other states

DOPL's plumbing FAQ confirms Idaho has reciprocal licensing agreements and points to a separate list of states. DOPL's site also hosts journeyman plumber reciprocity agreements with Montana, Oregon and Washington; each covers the journeyman certificate only, and each still requires an application in the destination state plus documented experience meeting that state's own requirements.

These documents are older, so before you plan around one, call DOPL directly at 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 Idaho Code 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 under 54-2606(3)(f) and IDAPA 24.39.20.300. Advertising as a plumbing contractor without a certificate, or advertising without the certificate number in the ad, is its own listed civil penalty offense under IDAPA 24.39.20.300.09.

New for 2026: the 48 business hour inspection rule

House Bill 585, signed March 31, 2026 and effective July 1, 2026 under session law chapter 232, created Idaho Code 54-2626A. If an inspection requested by a permit holder is not performed within 48 business hours, that permit holder may hire a third party inspector to perform it instead.

The permit holder notifies DOPL or the local government, provides a copy of the results, and is refunded the inspection fee already paid. There is a second provision most guides 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, so this changed scheduling risk for every licensed trade in Idaho construction on the same date, not just plumbing.

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, and DOPL states plainly that the Act requires registration, not licensure. There is no exam and no bond, but Idaho Code 54-5210(1)(e) requires proof of general liability coverage of not less than $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 that person is not acting to evade the chapter; an exempt person may not hold himself out as a registered contractor. The teeth matter anyway because they apply to the general contractors you work for: Section 54-5217(2) bars an unregistered contractor from bringing or maintaining a court action to collect compensation, and Section 54-5208 deems an unregistered contractor to have conclusively waived any right to place a lien on real property.

Idaho has no statewide general contractor license. The only construction credential with an exam is the Public Works Contractor License, which applies only to publicly funded projects, a distinction covered in the Idaho public works qualified individual guide. For the broader framework, see our guides on state vs. local contractor licensing and contractor license vs. business license.

Where the qualifier question comes in

Idaho Code 54-2610 makes it unlawful to engage in the business of plumbing in Idaho unless the person, or the responsible person representing a firm, has passed the required exam and holds a certificate of competency that cannot be transferred. That responsible person representing such firm language 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 rather than the company.

Section 54-2611(a) reinforces this: a contractor who personally does plumbing work must also be a qualified journeyman, or must employ a qualified journeyman on all work. Section 54-2611(b) defines the journeyman as someone who works in the employ and under the direction of a plumbing contractor, so 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 1099 consultant whose name sits on a license he has no real connection to. If you want the background on what a qualifying agent actually does, see what a qualifying agent is and how hiring one works; if you are weighing whether the licensed person has to be an owner rather than an employee, our contractor qualifier services page and our owner-vs-employee guide both cover what Idaho and other states actually require.

If your certificate holder just gave notice, the contractor qualifier contingency plan walks through the deadlines state by state. 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.

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 likely where the confusion starts.

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 run $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 under Idaho Code 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 directly that 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 holding a journeyman certificate, passing the contractor exam, and posting 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 schedule from $130 for up to 1,500 square feet to $325 plus $65 per additional 1,000 square feet over 4,500. 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. Cost depends on the classification, whether the business already has licensed staff, the scope and risk of the work, how many licenses the arrangement has to support, and how quickly a certificate holder needs to be seated. It is quoted per situation; talk through your Idaho project directly 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 at a time, and requires immediate written notice to DOPL when that representation changes.

Sources

• Idaho Division of Occupational and Professional Licenses, State Plumbing Board (retrieved 2026-10-15, page shows last updated August 28, 2026)
• DOPL Plumbing FAQs (retrieved 2026-10-15, page shows last updated May 27, 2026)
• DOPL Plumbing, Apply for or Renew a License (retrieved 2026-10-15)
• IDAPA 24.39.20, Rules Governing Plumbing, current rule (effective 3-28-23) (retrieved 2026-10-15)
• Idaho Code Title 54, Chapter 26, Plumbing and Plumbers (retrieved 2026-10-15)
• Idaho Code 54-2602, Exceptions (retrieved 2026-10-15)
• Idaho Code 54-2604, Plumbing systems (retrieved 2026-10-15)
• Idaho Code 54-2611, Classification of Competency (retrieved 2026-10-15)
• Idaho Code 54-2617, Certificate expiration and renewal (retrieved 2026-10-15)
• Idaho Code 54-2626A (retrieved 2026-10-15)
• House Bill 585 (2026 session), creating Idaho Code 54-2626A (retrieved 2026-10-15, signed 3/31/2026, ch. 232, effective 7/1/2026)
• PSI Combined Candidate Bulletin, effective 12.10.2025 (retrieved 2026-10-15)
• Idaho Contractor Registration Act, Title 54, Chapter 52 (retrieved 2026-10-15)
• Idaho Code 54-5210, Contractor Registration Act requirements (retrieved 2026-10-15)
• DOPL journeyman plumber reciprocity agreements: Montana, Oregon, Washington (retrieved 2026-10-15)

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 October 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.