Minnesota Plumber License Requirements (2026)

The Minnesota Department of Labor and Industry (DLI) Plumbing Board licenses plumbers and plumbing contractors statewide under Minn. Stat. §326B.435 through §326B.49. Minnesota uses a three-tier tradesperson path: Apprentice Plumber (registered with DLI), Journeyman Plumber (4-year apprenticeship totaling 7,000 hours plus 576 hours of classroom instruction and passing the DLI examination), and Master Plumber (minimum one year plus 1,700 hours as a licensed Journeyman followed by a separate Master exam). The Plumbing Contractor business license is a separate registration that requires a Master Plumber on staff, a $25,000 surety bond, and $300,000 general liability insurance.

The Licensing Authority

Minnesota Department of Labor and Industry — Construction Codes and Licensing Division (DLI) is the statutory authority responsible for issuing and enforcing this license under Minnesota Statutes Chapter 326B (Construction Codes and Licensing). DLI licenses residential building contractors, remodelers, electricians, plumbers, and mechanical (HVAC) contractors statewide; administers the Contractor Recovery Fund; and enforces the Minnesota State Building Code, Electrical Code, and Plumbing Code.

Official portal: https://www.dli.mn.gov/business/licensing-and-registration/
Address: 443 Lafayette Road N, St. Paul, MN 55155
Phone: (651) 284-5005

Baseline Eligibility

The applicant must be at least 18 years of age and possess a valid Social Security Number. No Minnesota residency requirement. Out-of-state plumbing contractors must designate a Minnesota registered agent.

Good moral character

DLI Plumbing Board reviews criminal history and prior license discipline on every application.

Background investigation

Mandatory criminal history disclosure on the application.

Experience and Education Requirements

At least 4 years of Journeyman Plumber: four-year registered apprenticeship totaling 7,000 hours of supervised plumbing work plus 576 hours of related classroom instruction. Master Plumber: minimum one additional year (1,700 hours) as a licensed Journeyman Plumber. has to be evidenced and confirmed. Retain payroll, tax, project, or supervisor records, since the board may audit the experience claimed.

Accepted proof of experience or eligibility

DLI Plumbing Experience Verification Form signed by each licensed Master Plumber supervisor
Registered Apprenticeship completion certificate from a DLI-approved program
Classroom instruction transcripts (576 hours)
W-2 statements, pay stubs, or 1099 records covering the qualifying period

Education substitution

Completion of a DLI-approved four-year plumbing apprenticeship is the standard path; accredited plumbing technology programs may count toward classroom hours but do not replace field hours.

The Licensing Examination

DLI Plumbing Board (directly administered) administers the required examination. Each part below must be passed before the license will issue:

Minnesota Journeyman Plumber Examination — Minnesota Plumbing Code, plumbing theory, installation practices — 100 questions, 240 minutes, passing score 70%
Minnesota Master Plumber Examination — code, isometrics, business and law, design — 100 questions, 300 minutes, passing score 70%

Examination fee: $50 Journeyman exam; $70 Master exam (paid directly to DLI).

Retake policy: Failed examinations may be re-taken by paying a new exam fee. DLI requires a 30-day wait between attempts on the same level. Applications remain valid for one year.

Financial Security and Insurance

The applicant must secure and file a $25,000 surety bond before the DLI will release the license.

General liability

Plumbing Contractor business licenses require $300,000 general liability insurance under Minn. Stat. §326B.46.

Workers' compensation

Workers' compensation insurance is mandatory in Minnesota under Minn. Stat. §176.181 for any business with employees.

Additional financial requirements

Plumbing Contractor business licenses require a $25,000 surety bond payable to the State of Minnesota in addition to the insurance minimums.

Fee Schedule

Fee	Amount
Application (non-refundable)	$120
Examination	$70
Initial license	$120
Renewal (every 2 years)	$120

License Renewal

The Minnesota Master Plumber (and Plumbing Contractor) must be renewed every 2 years. The fee to renew is presently $120. Minnesota plumber credentials renew on a two-year cycle aligned with the licensee's birth date.

Continuing education: 16 hours of DLI-approved continuing education every two years, including at least 8 hours on the Minnesota Plumbing Code and 1 hour on Minnesota-specific rules.

Downloadable Asset

2026 Minnesota Plumber License Roadmap (PDF) — a printable step-by-step checklist for the application process.

Download the PDF roadmap →

Reciprocity Map

Minnesota grants no NASCLA reciprocity for this classification.

Reciprocal State	Accepted Exam	Conditions
Wisconsin	Master Plumber exam waived	Bilateral DLI–Wisconsin DSPS Plumbing reciprocity for active Master Plumbers in good standing.
North Dakota	Master and Journeyman exams waived	Bilateral DLI–North Dakota State Plumbing Board reciprocity.
South Dakota	Master and Journeyman exams waived	Bilateral DLI–South Dakota Plumbing Commission reciprocity.
Iowa	Limited recognition	Case-by-case reciprocity with the Iowa Plumbing and Mechanical Systems Board; Minnesota-specific code exam may still be required.

Minnesota maintains formal bilateral plumber reciprocity with Wisconsin, North Dakota, and South Dakota. All reciprocal applicants must still register with DLI, submit the Minnesota application, and pay license fees.

Weighing more than one jurisdiction? The national hub compares Plumber license requirements in every state — exam, bond, fee, and experience thresholds side by side.

The Licensing Roadmap

Register as an Apprentice Plumber with DLI. All apprentices must register with DLI before working on plumbing installations under a Master Plumber's supervision.
Complete a four-year registered apprenticeship. 7,000 hours of supervised plumbing work plus 576 hours of related classroom instruction through a DLI-approved apprenticeship program.
Pass the Journeyman Plumber examination at 70%. DLI-administered exam covering the Minnesota Plumbing Code, theory, and installation practices.
Work at least one year as a licensed Journeyman. 1,700 hours of journey-level experience under a Master Plumber.
Pass the Master Plumber examination at 70%. DLI-administered exam covering code, isometrics, business and law, and design.
Receive the Master Plumber credential. DLI issues the credential after the exam is passed. The credential renews every two years.
Obtain the Plumbing Contractor business license. File the business license application designating a Master Plumber as the responsible person, with $25,000 surety bond and $300,000 general liability insurance.

Common Application Pitfalls

The following pitfalls summarize the issues most likely to delay, return, or derail a Minnesota Plumber application based on the published board instructions and source materials cited on this page.

Skipping apprentice registration

Working as an unregistered apprentice is a violation of §326B.46. Hours worked before registration do not count toward the 7,000-hour requirement.

Missing classroom instruction

Minnesota requires 576 hours of related classroom instruction across the four-year apprenticeship. Field hours alone do not qualify.

Confusing Master with Contractor

The Master credential authorizes the individual; the Plumbing Contractor license authorizes the business. Self-employed Masters need both.

Letting the Master credential lapse

A lapsed Master automatically suspends any Plumbing Contractor license that depends on the Master as the responsible person.

Ignoring the Minnesota Plumbing Code amendments

Minnesota adopts the UPC with significant state amendments (Chapter 4714). Studying only the base UPC will cause exam failures on Minnesota-specific questions.

Before Filing: A Checklist

Ahead of submission to DLI, confirm every item on this short list:

☐ DLI Apprentice Plumber registration
☐ 7,000 hours of supervised experience documented on the Experience Verification Form
☐ 576 hours of related classroom instruction transcripts
☐ DLI Journeyman Plumber exam pass certificate at 70%+
☐ DLI Master Plumber exam pass certificate at 70%+
☐ $25,000 surety bond and $300,000 general liability insurance (for the contractor license)
☐ DLI Plumbing Contractor business license application

Preparation Resources

The following references are cited by the regulator, used in the application process, or commonly used to prepare for the trade scope. Listed for reader convenience; CLR receives no compensation for these recommendations.

Minnesota Plumbing Code (Minnesota Rules Chapter 4714) — Minnesota Department of Labor and Industry. Primary technical reference. Open-book at the DLI test center.
Uniform Plumbing Code (UPC) — IAPMO. The Minnesota Plumbing Code is based on the UPC with Minnesota amendments.
Minnesota Statutes Chapter 326B and DLI Plumbing Board Rules — State of Minnesota. Licensing law and rules reference for the Master exam business and law portion.

Other Minnesota Trade Licenses

For a different Minnesota credential, see these companion guides published by CLR:

Answers to Common Questions

How many hours of experience does Minnesota require for a Journeyman Plumber?

7,000 hours of supervised plumbing work over a four-year registered apprenticeship, plus 576 hours of related classroom instruction. Hours must be documented on a DLI Experience Verification Form signed by a licensed Master Plumber.

What is the difference between a Master Plumber and a Plumbing Contractor in Minnesota?

A Master Plumber is the individual credential. A Plumbing Contractor is the business license that authorizes a company to bid and contract plumbing work. Every Plumbing Contractor must have a Master Plumber on staff as the responsible person.

Does Minnesota reciprocate plumber credentials?

Yes. DLI maintains bilateral reciprocity agreements with Wisconsin, North Dakota, and South Dakota for Master Plumbers (and in some cases Journeyman Plumbers). Applicants must still register with DLI and supply Minnesota-specific documentation.

What insurance does a Minnesota Plumbing Contractor need?

A $25,000 surety bond payable to the State of Minnesota and $300,000 general liability insurance under Minn. Stat. §326B.46.

How often does the Minnesota Master Plumber credential renew?

Every two years. Renewal requires 16 hours of DLI-approved continuing education including at least 8 hours on the Minnesota Plumbing Code.

Primary Sources

Regulatory requirements on this page are drawn from the official board, statute, and exam-provider materials listed below.

Verified 2026-04-26 · Next scheduled review 2026-07-25