Plumbing licensing is set by each state (and in some places by a city). This explainer covers Minnesota only, where plumbers are licensed by the Department of Labor and Industry (DLI). It answers one practical question from DLI's own pages: what experience do you need before you can take the journeyworker plumber exam, and how is that experience counted? Nothing here describes a rule change, and nothing here applies to any other state.
Can you do plumbing work in Minnesota before you are licensed?
Only if you are registered (or in a registered apprenticeship). DLI's Registered unlicensed plumbers page states: "An individual who is not licensed as a plumber may only perform plumbing work in Minnesota" if they are registered with DLI as a registered unlicensed plumber, a status the page describes as "formerly known as an apprentice".
Getting registered does not take experience. The same page states: "There is no work experience required to register as a registered unlicensed plumber".
DLI's Plumbing license basics page lists the conditions for working without a license: "You can perform plumbing work without a license only if:"
- "You are registered with DLI as a registered unlicensed plumber or enrolled in a registered apprenticeship program."
- "Your work falls under the scope of the work your employer is authorized to perform."
- "Your work is directly supervised at all times by a licensed journeyworker or master plumber."
The basics page also lists "At least 18 years old" among the conditions for performing plumbing work in Minnesota.
Two more limits appear on the Registered unlicensed plumbers page. For supervision, it makes an exception "For work in communities with a population under 5,000," where a license-restricted master or restricted journeyworker plumber may supervise. For employment, it says unlicensed plumbers must be W-2 employees of a "licensed plumbing contractor, licensed restricted plumbing contractor" or "a registered plumbing employer (for work performed on the employer's premises only)".
Who can take the journeyworker plumber exam?
DLI's Plumbing license experience requirements page states: "To qualify for the journeyworker plumber exam, an applicant must have:"
- "At least four years of recorded practical plumbing experience as a DLI-registered unlicensed plumber; or"
- "Completed a DLI-registered apprenticeship program; or"
- a current Minnesota restricted journeyworker or restricted master plumber license "and at least two years of practical plumbing experience gained while holding the restricted plumber license; or"
- "A current plumber's license from another state where the licensing jurisdiction requires at least four years of" practical plumbing experience and an examination.
DLI's Plumbing license basics page describes the restricted-license route differently: it lists holding "a restricted master plumber license" together with "five years of verifiable experience as a plumbing contractor," and does not mention the restricted journeyworker license. If you hold a restricted license, confirm with DLI which requirement applies to you.
Passing the exam comes before the license. The Plumbing license basics page states: "You must pass a written exam before you can apply for a journeyworker plumber license." It adds: "If you do not pass the exam you must wait 30 days before reapplying".
How many hours does a registered unlicensed plumber need?
The Registered unlicensed plumbers page says a registrant who has worked for four years can apply for the exam "once they have performed 7,000 hours of practical work experience." The experience requirements page sets the minimum hours by type of work: "Applicants who are registered unlicensed plumbers must demonstrate four years of practical plumbing experience, including:"
- "Water distribution system installation: 2,000 hours"
- "Drain, waste and vent system installation: 2,000 hours"
- "Fixture installation: 1,000 hours"
Those three add up to 5,000 hours. The Registered unlicensed plumbers page states: "The remaining hours may be in any aspect of plumbing work as defined in the code."
How is a year of experience counted?
DLI's experience requirements page sets several counting rules:
- "One year of practical plumbing experience consists of at least 1,750 hours" and "no more than 1,750 hours can be credited for one calendar year."
- "Not more than two years of practical plumbing experience from a state other than Minnesota will be credited" "unless the applicant first obtains a plumber's license in the other state."
- "Plumbing experience must be certified by the licensed master plumber responsible for the work performed."
- "Applicants must verify their own plumbing experience."
How do registered hours get on record?
Through yearly renewal. The Registered unlicensed plumbers page states: "Unlicensed registrations must be renewed by June 30 of each year." It adds: "To renew your registration you must submit your work experience for the past year." and "Employers do not submit this information." Renewal also requires continuing education: "Registered unlicensed plumbers must complete two hours of continuing education related to code by June 30 of each year."
Where to check before you act
These are DLI's requirements as shown on its pages on the date above. DLI's pages and Minnesota's statutes and rules are the authority, so confirm the current requirements with DLI before you register, count hours or apply for the exam. Restricted licenses, the master plumber exam and other credentials have their own requirements on DLI's site. Plumbing licensing is a planned topic on goraedu; see all certifications for its status.
goraedu is independent and is not affiliated with or endorsed by the Minnesota Department of Labor and Industry or any government agency.