- No dollar exemption is stated. Volunteers working on an owner's main home do not need a plumbing license.
- Journeyperson: four years as an apprentice in a registered apprenticeship, then pass the exam. Master: hold a journeyperson license with two years of work experience, or a master license from another jurisdiction.
- Plan for a trade exam.
- Surety bond of at least $5,000. Out-of-state contractors also file a $25,000 bond for contractor registration.
- Licenses run on a 3-year period and expire June 30 (valid through Aug 31). At least 8 hours of approved continuing education each 3-year term.
Do you need a state license in Iowa?
Iowa licenses plumbing work at the state level through the Iowa Plumbing and Mechanical Systems Board, Department of Inspections, Appeals, and Licensing (DIAL). Below is what the board asks for, in the order you will run into it.
No dollar exemption is stated. Volunteers working on an owner's main home do not need a plumbing license.
Check with the city or county for each project about local permit and inspection rules.
Iowa license types for plumbing work
Iowa splits the work into 3 licenses. Pick the one that matches the jobs you take, since working outside its scope is the same as working without one.
| License | What it covers |
|---|---|
| Master plumber | Plans and supervises the design, installation and repair of plumbing, and can run the business side. |
| Journeyperson plumber | Does plumbing work under the supervision of a licensed master. |
| Plumbing contractor | The business license for anyone who does plumbing work for customers under a contract. |
Steps to get licensed in Iowa
- Work as an apprentice in a US Department of Labor registered apprenticeship for four years.
- Pass the Iowa journeyperson plumbing exam and get your journeyperson license.
- After two years as a journeyperson, file the exam approval application ($35) and pass the master exam at Kirkwood.
- Apply for your master plumber license.
- Get $500,000 liability insurance, a $5,000 surety bond and an Iowa unemployment insurance number.
- Apply for the plumbing contractor license and DIAL contractor registration in one application.
Experience and other requirements
Experience. Journeyperson: four years as an apprentice in a registered apprenticeship, then pass the exam. Master: hold a journeyperson license with two years of work experience, or a master license from another jurisdiction.
The license to apply for. Plumbing contractor license (you hold, or employ, a licensed master plumber).
Iowa plumbing exams
Trade exam. Iowa Plumbing and Mechanical Systems Board master exam for plumbing, given by Kirkwood Community College.
Business and law exam. The official pages we read do not say. Check with the board (official site).
What it costs in Iowa
The board lists 4 fees along the way. These are the state's own numbers. Insurance, any bond, exam prep and your business registration come on top.
| Fee | Amount |
|---|---|
| Exam approval application, per trade exam | $35 |
| Master exam fee paid to Kirkwood, per attempt | $95 |
| Master license, applied for July 1 to Dec. 31 of year 1 of the 3-year period (less later) | $240 |
| Contractor license plus contractor registration, July 1 to Dec. 31 of year 1 (less later) | $400 |
Insurance and bond
Insurance. Public liability insurance of at least $500,000. Workers' compensation if you have one or more employees.
Bond. Surety bond of at least $5,000. Out-of-state contractors also file a $25,000 bond for contractor registration.
Renewal and licenses from other states
Renewal. Licenses run on a 3-year period and expire June 30 (valid through Aug 31). At least 8 hours of approved continuing education each 3-year term.
Reciprocity. Iowa has a reciprocity agreement with South Dakota for journeyperson and master plumbing licenses earned by written exam.
Good to know in Iowa
- The contractor license and the DIAL contractor registration go in one joint application.
- You need an Iowa unemployment insurance number even if you have no employees.
- A master can be the master of record for only one contractor per discipline unless the board approves more.
After you are licensed
The license lets you take the work. Getting the work is the next job.
- Register the business. If you work under a name other than your own, register it where your state asks (often the Secretary of State, sometimes the county), and keep the name the same on your license, your truck and your invoices.
- Claim your Google Business Profile. It is the listing people see when they search for a plumber near them. Fill in your service area, hours and real photos of your work.
- Put up a website that shows the license. Customers look for it before they call. Koira builds a contractor website for you and keeps it current.
- See where you stand. The free Koira report checks how your business shows up in search and on maps against shops near you.
Where this comes from
Every fact on this page comes from the Iowa Plumbing and Mechanical Systems Board, Department of Inspections, Appeals, and Licensing (DIAL) and the official pages below, checked October 8, 2026. Fees and rules change, so confirm with the board before you file.
More for your trade: how plumbing companies run on Koira.