Who licenses plumbers in Iowa?
Iowa licenses plumbers statewide through the Department of Inspections, Appeals, and Licensing Plumbing and Mechanical Systems Board (PMSB). The board’s licensure page provides separate routes for apprentice, journey, master and contractor credentials. (Iowa DIAL)
The individual and business credentials are related but not interchangeable. Journey and master licenses establish individual trade authority; the contractor license and registration address the business offering plumbing services. Keep both records current when the company contracts the work.
Apprentice, journey, master and contractor
| Level | Core role | Gate to the next step |
|---|---|---|
| Apprentice | Learns and performs covered work under required supervision | Registered apprenticeship credit and exam eligibility |
| Journeyperson | Performs the licensed discipline at journey level | Two years of journey work experience for the Iowa master exam route |
| Master | Plans or superintends covered work and may serve as master of record | Maintain active discipline-specific status |
| Contractor | Person or entity that provides covered services for a predetermined contract amount | Joint contractor license and registration, insurance, bonds where applicable, and master of record |
Iowa requires all plumbing and mechanical contractors to be licensed with PMSB and registered with DIAL. (Iowa DIAL contractor-license page) For the broader registration framework, see our Iowa contractor-registration guide.
Journey and master examination eligibility
For journeyperson examination eligibility, DIAL says a candidate must either complete at least 36 months in a U.S. Department of Labor registered apprenticeship or have at least four years of experience before January 1, 2010. (Iowa DIAL examination page) Apprentices may apply to sit for the exam up to six months before completing the required 48 months of apprentice credit; early exam eligibility is not the same thing as completed apprentice credit.
A master exam candidate must either have been licensed as a journeyperson and have two years of journey-level work experience in the discipline, or have been licensed as a master in that discipline in another state or local jurisdiction. (Iowa DIAL master-license page)
Build a dated experience record before applying. Our experience-verification guide shows how to organize employers, supervisors, licenses, dates and scope without turning estimates into unsupported hours.
The contractor license has two separate bond questions
The PMSB contractor application requires an active master of record in each discipline. It also requires public-liability insurance of at least $500,000. The PMSB performance surety bond must be at least $5,000. (Iowa DIAL contractor-license page) It also requires the contractor-license and DIAL-registration pieces to stay aligned.
Do not confuse the $5,000 PMSB performance bond with the separate $25,000 out-of-state contractor-registration bond. DIAL says out-of-state contractors must file the $25,000 bond at registration and renewal, subject to the stated transportation-project exception. (Iowa DIAL contractor-license page) Our contractor-bond explainer explains why a bond is not liability insurance.
Application sequence
- Choose the discipline and level. Plumbing, HVAC/refrigeration, hydronics, mechanical and sheet metal are not interchangeable categories.
- Build exam eligibility. Use the apprenticeship or prior-license route that applies to journey or master.
- Submit the exam-candidate application. To be eligible to sit for an examination, an applicant must first complete an Iowa Examination Candidate Application. (Iowa DIAL examination page)
- Test through the approved provider. DIAL currently identifies Kirkwood Community College as the approved provider.
- Apply after passing. A license is not automatically issued after the examination; the applicant must submit the post-examination licensure application. (Iowa DIAL examination page)
- Add the contractor layer before contracting. Align the business name, master of record, insurance, surety bond, unemployment-insurance number and contractor registration.
DIAL’s July 2026 notice says application reviews can take up to six weeks. (Iowa DIAL licensure page) Treat that as a planning ceiling, not a promised turnaround for every file.
Current three-year period and posted fees
DIAL says all PMSB licenses use a three-year period, with the current period running July 1, 2026 through June 30, 2029. (Iowa DIAL fee page) New-license fees are prorated by filing date.
| Posted fee | Current amount |
|---|---|
| Exam approval application, per exam | $35 |
| Full apprentice fee | $50 |
| Full journeyperson fee | $180 |
| Full master fee | $240 |
| Full contractor license plus registration | $400 ($250 + $150) |
| Paper application fee, when applicable | $25 |
DIAL posts full amounts of $50 for apprentice, $180 for journeyperson, $240 for master, and $400 for the contractor license plus registration. The exam-approval application is $35 per exam, and the paper-application fee is $25 when applicable. (Iowa DIAL fee page) The testing provider charges separately, so verify its current amount when scheduling.
PMSB’s basic continuing-education requirement is at least eight classroom hours during each three-year licensing term. (Iowa DIAL licensure page)
Reciprocity is narrow: Iowa and South Dakota plumbing
Iowa’s published reciprocity agreement is with the South Dakota State Plumbing Commission and applies only to journeyperson and master plumbing requirements. It allows a person whose South Dakota plumbing license was obtained by written examination to seek a similar Iowa license without taking another Iowa exam, while still complying with Iowa’s other laws and rules. (Iowa DIAL master-license page)
The applicant must have a non-Iowa resident address when applying and submit the South Dakota license plus good-standing verification. Do not generalize that agreement to every state or discipline. Our license-reciprocity guide explains the difference between exam waiver, license recognition and authority to work.
Frequently asked questions
Who licenses plumbers in Iowa?
The Iowa Department of Inspections, Appeals, and Licensing Plumbing and Mechanical Systems Board licenses plumbers statewide.
When can an apprentice apply for the journeyperson exam?
DIAL says an apprentice may apply up to six months before completing the required 48 months of apprentice credit, subject to the examination-candidate requirements.
What does Iowa require for the master exam route?
A candidate generally needs a journeyperson license plus two years of journey-level experience in the discipline, or a master license in that discipline from another jurisdiction.
Does a plumbing contractor need both a license and registration?
Yes. Iowa requires plumbing and mechanical contractors to hold the PMSB contractor license and DIAL registration, submitted through the joint process.
How often do PMSB licenses renew?
They use a three-year licensing period. The current period posted by DIAL is July 1, 2026 through June 30, 2029.
Does Iowa reciprocate with every state?
No blanket agreement is published. DIAL describes a plumbing agreement with South Dakota for qualifying journeyperson and master licenses issued by written examination.