Getting a Minnesota plumber license is one of the most structured licensing paths in the trades. The state requires documented apprenticeship hours, a passing score on a state exam, and a completed application through the Department of Labor and Industry (DLI) — there are no shortcuts. The good news: once you understand the requirements, the path is clear.
This guide covers everything you need to know: the license types available, how to meet the prerequisites, what the exams cover, how to apply, and the fees involved.
Minnesota Plumber License Types
The DLI issues several categories of plumbing licenses in Minnesota. The two primary licenses for working plumbers are:
| License Type | Who It's For | Key Requirement |
|---|---|---|
| Journeyworker Plumber | Entry-level licensed plumbers | Complete DLI-registered apprenticeship + pass journeyworker exam |
| Master Plumber | Experienced plumbers who supervise or run a business | Hold journeyworker license + additional experience + pass master exam |
| Restricted Master Plumber | Plumbers in limited geographic/scope areas | Meet DLI-specified restricted requirements |
| Plumbing Contractor | Businesses offering plumbing services | At least one licensed master plumber on staff |
Most people start with the Journeyworker license. The Master license comes after you've logged field experience as a journeyworker. You cannot skip directly to Master without first holding a Journeyworker license.
Education & Experience Prerequisites
Journeyworker Plumber
To qualify for the Journeyworker Plumber exam in Minnesota, you must complete an approved apprenticeship program. The standard requirement is:
- 4 years (approximately 8,000 hours) of on-the-job training in a DLI-registered apprenticeship program
- Completion of related technical instruction (typically through a joint apprenticeship training committee or a trade school)
Apprenticeship programs are administered through organizations like the Minnesota Plumbing and Mechanical Contractors Association (PMCA) and United Association Local 15. You must be enrolled in a DLI-registered program — informal on-the-job experience does not count toward the hour requirement.
Some applicants with out-of-state hours may petition the DLI for credit toward Minnesota requirements. This is evaluated case-by-case — contact the DLI directly if you have prior apprenticeship experience in another state.
Master Plumber
To qualify for the Master Plumber exam, you must:
- Hold an active Minnesota Journeyworker Plumber license
- Have a minimum of 1 year of journeyworker-level field experience after receiving your journeyworker license
The Master exam is significantly more difficult than the Journeyworker exam and covers code knowledge, business operations, and plan review — not just hands-on installation skills.
Exam Requirements
Both the Journeyworker and Master exams are administered by PSI Exams on behalf of the DLI. Key details:
- Content: Based on the Minnesota Plumbing Code (which incorporates the Uniform Plumbing Code with state amendments). The exams test practical plumbing knowledge, code compliance, and problem-solving.
- Format: Multiple choice, computer-based
- Passing score: 70% or higher
- Scheduling: Register through PSI Exams at dli.mn.gov
- Retakes: Allowed after a waiting period; additional exam fees apply
Prepare using the current edition of the Minnesota Plumbing Code. Many candidates use study guides published by the PMCA or trade schools — raw code reading alone is rarely enough for first-time test-takers.
Application Process
Once you've passed your exam, you apply for your license through the DLI. The process is done online:
- Go to dli.mn.gov and navigate to Plumber Licensing
- Create or log in to your DLI account
- Complete the license application and upload supporting documents (exam results, apprenticeship completion certificate, any out-of-state experience documentation)
- Pay the application fee online
- Wait for DLI processing — typically 5–10 business days for complete applications
- Download your license certificate once approved; your active status will appear in the DLI database
Your license will show as Active in the DLI database within 24 hours of issuance. You can verify it instantly:
Verify a Minnesota plumber license →
License Fees
Fees are set by the DLI. Always confirm current amounts at dli.mn.gov before applying — they are periodically updated.
| Fee Type | Approximate Amount | Notes |
|---|---|---|
| Journeyworker initial application | ~$60 | Confirm at dli.mn.gov |
| Master initial application | ~$80 | Confirm at dli.mn.gov |
| PSI exam fee | ~$85–$105 | Paid directly to PSI Exams |
| Retake exam fee | Same as initial exam | Per attempt |
| License renewal (every 2 years) | Verify at dli.mn.gov | Renewal required biennially |
The total out-of-pocket cost for a first-time Journeyworker license (exam + application) is typically under $200. The larger investment is your time in the apprenticeship program.
Common Application Mistakes
These are the most frequent reasons first-time applicants run into delays or rejections:
- Applying before your exam results are official — The DLI requires your official PSI score report. PSI typically delivers results within a few days of the exam, but don't submit your application before the score is on record.
- Incomplete apprenticeship documentation — Your completion certificate must come from your DLI-registered program. A letter from your employer is not sufficient. Confirm your training sponsor has officially closed out your apprenticeship record before applying.
- Out-of-state hours with no petition — If any of your training hours were completed in another state, you need DLI approval to count them. Submitting an application that assumes those hours are accepted — without getting approval first — leads to automatic rejection.
- Wrong license type on the application — Journeyworker and Master applications are separate. Double-check that you're applying for the correct license type and that you meet all prerequisites for that specific license.
- Not checking your status after approval — Once you receive approval, verify your license appears as Active in the DLI database before you start work. Processing errors are rare but happen. Search your name or license number to confirm:
Search Minnesota plumber license records →
After You're Licensed
Your Minnesota plumber license is valid for 2 years. Renewal requires continuing education hours and a renewal fee — the DLI mails a notice before expiration, but the notice is not a substitute for your own calendar. Plenty of licensed plumbers miss it every year.
Our monitoring service tracks your license status daily and sends email alerts at 90, 60, and 30 days before expiration — so you never have to wonder if you're still current.
Monitor your plumber license for $29/mo — expiration alerts, status change notifications, and instant access to your full DLI record. Set it up once and never miss a renewal deadline.
Ready to verify your license status or look up another plumber?
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