Iowa Plumbing License Requirements — PMSB Exams, Fees, and Renewal
Iowa Plumbing Licenses Are State-Level — Not Local
Unlike general contractor registration, plumbing in Iowa requires a real state license with exams and continuing education. The Plumbing and Mechanical Systems Board (PMSB) regulates all plumbing, HVAC, mechanical, refrigeration, hydronics, and sheet metal work statewide. No city can override this — state preemption means a PMSB license is the only valid plumbing credential in Iowa.
A business cannot contract for plumbing services without both a PMSB contractor license and an active Master of Record on staff. Working without the license exposes the contractor to enforcement action from both the board and local building departments, which verify PMSB credentials before issuing plumbing permits.
License Classes and Who Needs What
The PMSB issues licenses across several categories. For plumbing, the primary ones are:
Apprentice Plumber — Entry-level registration while learning the trade under a licensed journeyman or master. No exam required, but the apprenticeship must be registered.
Journeyman Plumber — The working credential. Requires passing the Kirkwood Community College trade exam and completing the required apprenticeship hours.
Master Plumber — The supervisory credential. Required to serve as a company's Master of Record. More extensive exam, more experience required.
Plumbing Contractor License — The business credential. Required for any company that contracts for plumbing work. Must employ an active Master of Record. Issued jointly with a DIAL contractor registration through a combined application.
Exam Logistics: Kirkwood Community College
Unlike electrical exams (administered by PSI), plumbing and mechanical exams are administered through Kirkwood Community College across 15 testing sites in Iowa.
Before you can schedule an exam, you need sponsoring approval from the PMSB. Submit your exam approval application to the board first, pay the $35 state exam approval fee, and wait for authorization. Only after receiving approval can you register with Kirkwood.
The Kirkwood exam registration fee is $35 per trade exam.
Journeyman Plumbing with Gas exam: Open-book, 3 hours, 75 questions. Covers the 2024 Uniform Plumbing Code (UPC) and the International Fuel Gas Code. Passing score: 75%.
Master Plumbing with Gas exam: Open-book, 5 hours, 125 questions. Same code references. Passing score: 75%.
If you fail, you must wait 30 days before scheduling a retake. Each retake requires the $35 Kirkwood fee.
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Fees: The Triennial Cycle
PMSB licenses run on a fixed 3-year cycle. The current cycle is July 1, 2026, through June 30, 2029. Initial fees are prorated based on when you enter the cycle — applying early costs more, but you get more years on the license.
For the combined PMSB Contractor License + DIAL Contractor Registration:
| Application Window | License Fee | Registration Fee | Total |
|---|---|---|---|
| Jul–Dec, Year 1 | $250.00 | $150.00 | $400.00 |
| Jan–Jun, Year 1 | $208.50 | $125.00 | $333.50 |
| Jul–Dec, Year 2 | $166.75 | $100.00 | $266.75 |
| Jan–Jun, Year 2 | $125.00 | $75.00 | $200.00 |
| Jul–Dec, Year 3 | $83.25 | $50.00 | $133.25 |
| Jan–Apr, Year 3 | $41.75 | $25.00 | $66.75 |
The renewal window runs May 1 through June 30 of Year 3, with a full-term renewal fee of $466.75.
Paper applications carry a $25 surcharge. Filing online avoids this. If you apply for multiple license classes on the same day (e.g., Journeyman and Master in different disciplines), a 30% discount applies to the license portion — but not to registration fees, late fees, or the paper surcharge.
Insurance and Bond Requirements
PMSB-licensed plumbing contractors must carry:
- $500,000 minimum public liability insurance — higher than the general contractor standard
- $5,000 surety bond — separate from the state DIAL registration bond
These are specific to the PMSB license. If you also have employees, you still need the $25,000 DIAL surety bond and workers' compensation coverage on top of these PMSB requirements.
Continuing Education
Licensees must complete 8 classroom hours of board-approved continuing education during each 3-year cycle. The curriculum must include:
- 2 hours of safety content
- 2 hours of code content
- 2 hours of discipline-specific content
- 2 hours of elective content
A maximum of 4 hours can be completed online — the rest must be in-person classroom instruction. CE must be completed before the renewal window opens.
Reciprocity
Iowa's plumbing license reciprocity is limited. The PMSB maintains an active reciprocity agreement solely with South Dakota. Licensed plumbers from South Dakota can apply for Iowa licensure through the reciprocal pathway, which typically waives the exam requirement.
For all other states, you'll need to go through the standard exam approval and testing process at Kirkwood — regardless of your licensing history in your home state.
For mechanical and HVAC, the PMSB has no reciprocity agreements with any state.
Getting Started
The Iowa General Contractor License Guide covers the complete plumbing licensing pathway alongside general contractor registration, including how the joint PMSB + DIAL application works, insurance requirements across both credentials, and specialty trade exam logistics.
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