Plumbing Contractor License in Iowa: Requirements, Qualifier, Bond and Exams

Statewide.

Iowa requires a board license to contract for plumbing work, and the same licensing statute covers plumbing, mechanical, HVAC, refrigeration, sheet metal and hydronic systems: a person shall not operate as a contractor or install or repair those systems without a license from the Plumbing and Mechanical Systems Board, which now sits within the Iowa Department of Inspections, Appeals, and Licensing (DIAL).

State licensing also replaces local licensing — the statute supersedes and preempts the plumbing, mechanical, HVAC-refrigeration, sheet metal, hydronic and contracting licensing provisions of every governmental subdivision, and city and county plumbing and mechanical licenses became void on July 1, 2009.

Cities may still charge permit and inspection fees on the work.

The Plumbing and Mechanical Systems Board issues the contractor license; the board now sits within the Iowa Department of Inspections, Appeals, and Licensing (DIAL).

Iowa plumbing contractors are licensed by the same board under the same rules as HVAC contractors — the same master-of-record, insurance, bond and fee rules — and the contractor license comes in the board's disciplines, plumbing among them.

Below the contractor license, the board's ladder runs apprentice, journeyperson and master, and it is the same for plumbing as for HVAC: a plumbing license allows an individual to perform work defined as plumbing.

Master licenses exist in plumbing, mechanical, HVAC-refrigeration and hydronic, and the journeyperson licenses add sheet metal to that list.

The qualifier is a master licensee.

To get the license, a contractor must hold a master license or employ at least one person holding a master license, and any business doing plumbing or mechanical work must at all times have a licensed master actively in charge of the work — responsible for the proper designing, installing, and repairing — a sole proprietor must personally be a licensed master.

The qualifier's credential sits at the top of the board's ladder, which is the same for plumbing as for HVAC.

A journeyperson license takes the journeyperson exam plus at least four years of practical experience as an apprentice in a registered apprenticeship program, and applicants may test up to 12 months before finishing the 48 months.

The master license takes the master exam plus at least two years as a licensed journeyperson in the discipline (or a prior master license).

Our guide to the HVAC contractor license qualifier explains the qualifier's role where a state license requires one, and our Iowa plumbing licence for individuals page follows the apprentice-to-master ladder in detail.

The exams Iowa's licensing rules confirm sit on the licenses your qualifier holds: the journeyperson exam on the way up and the master exam to qualify.

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 found no separate contractor business-and-law exam in the statute and rules we read; confirm with the board whether anything else is required at application.

Iowa plumbing and mechanical contractors must provide evidence of a public liability insurance policy and a surety bond, in an amount determined sufficient by the board by rule, and the contractor license requirements also include proof of workers' compensation and unemployment insurance compliance.

The statute and rules our research read set no dollar minimums for the liability policy or the bond, so ask the board what amounts it currently accepts before you buy the coverage.

Out-of-state contractors also need the chapter 91C bond.

Our guide to contractor license bonds and insurance covers how surety bonds work where a state requires one.

The contractor license costs $250 for three years.

All licenses the board issues run on the same clock — they expire on June 30 every three years, beginning with June 30, 2026 — so the contractor license and the shop's master and journeyperson licenses renew together.

Each three-year term requires at least 8 classroom hours of board-approved continuing education, and Iowa law gives a 30-day grace period after expiration.

Budget the rest of the shop's licenses too: the qualifier's master license is $240 for three years, the journeyperson license $180, the apprentice license $50, and the exam application fee is $35 with exam fees paid separately to the board's testing vendor.

Conditionally, and at the board's discretion.

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.

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 bid work.

Watch the extra cost too: out-of-state contractors also need the chapter 91C bond.

The requirement keeps running: any business doing plumbing or mechanical work must at all times employ a licensed master who is actively in charge of the work, so a master who resigns leaves the business out of compliance until another master takes that role.

How long you have to replace a departing master is not stated in the statute or rules our research read, so contact the board as soon as you know your master plans to leave.

Because the statute says at all times, start the replacement search the day your master gives notice — and confirm the board's process for listing a new master on the license directly with the board.

It can, depending on the work you sell.

Installing or repairing medical gas piping takes a separate board-approved certification on top of the license, and applicants need a valid certification from the National Inspection Testing Certification (NITC) Corporation, or an equivalent authority approved by the board; the medical gas certificate costs $75 for three years.

Our research also saw a backflow prevention assembly tester registration as a separate program, but only in a rules transfer table — we did not research its details, so ask the board what it currently requires before you sell backflow testing.