How Do You Get a Plumbing License in Iowa?
Yes: Iowa licenses plumbing work statewide through the Plumbing and Mechanical Systems Board, within the Department of Inspections, Appeals, and Licensing (DIAL), and state licensing replaces city and county plumbing licenses.
Nobody may install or repair plumbing in Iowa without a board license.
The ladder runs apprentice, journeyperson, master and contractor: journeyperson takes at least four years of apprentice experience plus an exam, master at least two more plus another exam, and all of the board's licenses renew on a three-year cycle with at least 8 CE hours per term.
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At a glance
Yes.
Nobody may install or repair plumbing systems in Iowa without a Plumbing and Mechanical Systems Board license, and state licensing preempts city and county licensing.
The Plumbing and Mechanical Systems Board, now within the Iowa Department of Inspections, Appeals, and Licensing (DIAL).
Apprentice, Journeyperson and Master licenses in plumbing, plus a contractor license for businesses that hold or employ a master licensee.
Journeyperson: at least 4 years as an apprentice in a registered apprenticeship program.
Master: at least 2 years as a licensed journeyperson.
Apprentice: age 18, a high school diploma or GED, and enrollment in a registered program.
Journeyperson and master exams, administered by a board-approved testing vendor whose name is not stated in the rules our research read — ask the board.
All board licenses expire June 30 every three years, beginning June 30, 2026; at least 8 classroom hours of board-approved CE per term, with a 30-day grace period after expiration.
Possible without examination when the other state's requirements are similar and it grants Iowa licensees the same privilege; no partner-state list appears in our research.
Our research notes a DIAL licensing search but did not capture its web address — start from the Department of Inspections, Appeals, and Licensing (DIAL), the department that houses the board.
The Iowa plumbing license ladder
- Apprentice License (Plumbing)Entry level
The entry license: you work under a licensed journeyperson or master in plumbing and stay enrolled in a registered apprenticeship program; it costs $50 for three years.
- Journeyperson License (Plumbing)Journeyman
Issued after the journeyperson exam and at least four years of practical experience as an apprentice; a plumbing license allows the holder to perform work defined as plumbing.
- Master License (Plumbing)Master
Issued after the master exam and at least two years as a licensed journeyperson in plumbing (or with a prior master license); a business needs a master on staff to hold the contractor license.
- Plumbing Contractor LicenseContractor
The business license from the same board: a master license on staff, insurance and a bond, $250 for three years; the employer-side requirements sit with the contractor series.
Does Iowa require a state plumbing license?
Yes.
Iowa requires a board license to install or repair plumbing, and the requirement is statewide: the licensing statute says a person shall not operate as a contractor or install or repair plumbing, mechanical, HVAC, refrigeration, sheet metal or hydronic systems without a license issued by the Plumbing and Mechanical Systems Board, which now sits within the Department of Inspections, Appeals, and Licensing (DIAL).
State licensing also preempts local licensing.
City and county plumbing and mechanical licenses became void on July 1, 2009, though cities may still charge permit and inspection fees.
“a person shall not operate as a contractor or install or repair plumbing, mechanical, HVAC, refrigeration, sheet metal, or hydronic systems without obtaining a license issued by the board”
What are the Iowa plumbing license levels, and what can each legally do?
Iowa's plumbing ladder is apprentice, journeyperson, master and then the contractor license, and a plumbing license is what allows an individual to perform work defined as plumbing.
The same board issues journeyperson and master licenses in plumbing alongside parallel mechanical, HVAC-refrigeration and hydronic licenses, with sheet metal licensed at the journeyperson level only.
Above master sits the contractor license: a plumbing contractor must hold a master license or employ at least one master licensee, carry insurance and a bond, and pay $250 for a three-year license.
“A plumbing license shall allow an individual to perform work defined as plumbing.”
What does each level require: hours, training, exam and fees?
The apprentice license requires working under a licensed journeyperson or master in the discipline and enrollment in a registered apprenticeship program, and applicants must be 18 and hold a high school diploma or GED.
The journeyperson license requires the state journeyperson exam and at least four years of practical experience as an apprentice in a registered apprenticeship program, a requirement since January 1, 2010; applicants may test up to 12 months before finishing the 48 months.
The master license requires the master exam and at least two years of experience as a licensed journeyperson in the discipline, or a prior master license.
Three-year fees: $50 apprentice, $180 journeyperson, $240 master, plus a $35 exam application fee.
“Provide the board with evidence of having completed at least four years of practical experience as an apprentice.”
Who gives the Iowa plumbing exam, and what is on it?
The ladder has two exams: the journeyperson exam and the master exam.
Iowa's rules say the exams are administered by the board-approved vendor, and the vendor's name does not appear in the rules our research read, so ask the board which testing vendor it currently uses.
The exam application costs $35, and the exam fee itself is paid separately to that vendor.
Our research also does not describe what the exams cover, so ask for the candidate information when the board approves your exam application.
How do you renew, and how many CE hours does Iowa require?
Every license the board issues runs on a three-year term, and all licenses expire on June 30 every three years, beginning with June 30, 2026 — apprentice, journeyperson and master licenses renew together on the same date.
The three-year license fees are $50 for an apprentice license, $180 for a journeyperson license and $240 for a master license.
Before renewal you need at least 8 classroom hours of board-approved continuing education in the term, and Iowa law gives a 30-day grace period after expiration.
“All licenses issued will expire on June 30 every three years, beginning with June 30, 2026.”
Does Iowa accept plumbing licenses from other states?
Conditionally.
The board may license without examination a nonresident applicant who is licensed under another state's plumbing, mechanical, HVAC-refrigeration, sheet metal or hydronic licensing statutes, when those requirements are similar to Iowa's and the other state grants Iowa licensees the same privilege.
That is the statute's own condition, and Iowa names no partner states in the material our research read, so confirm with the board how your out-of-state license, experience and exams translate before you count on a waiver.
“The board may license without examination a nonresident applicant who is licensed under plumbing, mechanical, HVAC-refrigeration, sheet metal, or hydronic professional licensing statutes of another state having similar licensing requirements”
How do you look up an Iowa plumbing license?
The board sits within DIAL, and our research notes a DIAL licensing search for state licenses, but we could not capture the search's web address or confirm what it covers.
Start from the Department of Inspections, Appeals, and Licensing (DIAL), which now houses the board, and use its licensee search from there.
Verify a license before you hire a contractor, and before you take a job with a company that claims licensed status.
Do medical gas or backflow work need separate Iowa credentials?
Medical gas does.
Installing or repairing medical gas piping takes a separate board-approved certification: applicants must hold a valid certification from the National Inspection Testing Certification (NITC) Corporation or an equivalent authority the board approves, and the medical gas certificate costs $75 in the three-year fee schedule.
Backflow is less settled in our research: Iowa appears to register backflow prevention assembly testers under a separate program (a chapter now numbered 481 IAC chapter 476, formerly 641 IAC 26), but the details were not part of the rules we read, so confirm backflow requirements with the board.
What This Page Does, and Doesn’t, Cover
This page summarizes the Iowa board pages, statutes, rules and other sources listed below, as read for this state-by-state plumbing licensing series, current as of September 2026.
It is not a substitute for the instructions the Plumbing and Mechanical Systems Board, Iowa Department of Inspections, Appeals, and Licensing (DIAL) publishes.
For the rest of the picture in Iowa, see HVAC licensing in Iowa, plumbing apprenticeships in Iowa, plumbing contractor licensing in Iowa, and plumber pay in Iowa.
Frequently Asked Questions
How long does it take to get a plumbing license in Iowa?
Plan on at least four years to reach journeyperson.
You start with an apprentice license, which requires working under a licensed journeyperson or master and enrollment in a registered apprenticeship program, then qualify with the journeyperson exam and at least four years of practical experience as an apprentice.
The master license takes at least two more years as a licensed journeyperson plus the master exam.
You may sit the journeyperson exam up to 12 months before finishing the 48 months.
How much does an Iowa plumbing license cost?
State fees are $35 to apply for an exam, then $50 for a three-year apprentice license, $180 for a journeyperson license and $240 for a master license.
The plumbing contractor license is $250 for three years and the medical gas certificate is $75.
The testing vendor charges its exam fee separately from the board's $35 application fee.
Does Iowa have plumbing license reciprocity?
Conditionally.
Iowa's licensing statute lets the board license a nonresident without examination when their state's plumbing licensing requirements are similar to Iowa's and that state extends the same privilege to Iowa licensees.
Iowa names no partner states in the material our research read, so contact the board before assuming your out-of-state license transfers without an exam.
How many CE hours do Iowa plumbers need?
Iowa requires at least 8 classroom hours of board-approved continuing education in each three-year licensing term.
All licenses the board issues expire together on June 30 every three years, and Iowa law gives a 30-day grace period after expiration.
Confirm the current CE requirement with the board before you renew.
Do Iowa cities issue their own plumbing licenses?
No. State licensing preempts city and county plumbing and mechanical licensing, and local licenses became void on July 1, 2009.
Cities can still charge permit and inspection fees, so you may still deal with the local building department on a job site, but the license itself comes from the state board.
More Iowa Resources
Sources
- Iowa Code ch. 105 (plumbing, mechanical, HVAC-refrigeration, sheet metal and hydronic licensing) (retrieved 2026-09-29)
- 481 Iowa Administrative Code ch. 429 (licensing rules: experience, renewal, medical gas) (retrieved 2026-09-29)
- 481 Iowa Administrative Code ch. 428 (fee schedule) (retrieved 2026-09-29)
- 641 Iowa Administrative Code (transfer-table reference cited for the backflow tester registration) (retrieved 2026-09-29)
Sourced from the documents listed above.
Verified September 2026.
This is career information, not legal advice.
Confirm current rules with the Plumbing and Mechanical Systems Board, Iowa Department of Inspections, Appeals, and Licensing (DIAL).