Minnesota Master Plumber licensing is issued by the Commissioner of Labor and Industry, and the examination is given by the Minnesota Department of Labor and Industry itself — a state-run sitting with no third-party vendor. The master examination consists of 300 points in 5.5 hours, the passing score for all examinations is 70 percent, and all reference materials are provided by the department. The PassProfessor Minnesota Master Plumber program prepares candidates for that examination on the 2020 Minnesota Plumbing Code.
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What this credential certifies
A Minnesota Master Plumber holds the top examined plumbing license in the system governed by Minnesota Statutes chapter 326B and Minnesota Rules chapters 4716 and 4714. The tier below is spelled, in current Minnesota usage, the Journeyworker Plumber — this page uses “journeyworker” throughout, as the Minnesota sources do.
The master license is issued by the Commissioner of Labor and Industry. The Minnesota Plumbing Board adopts the Plumbing Code and the licensing and continuing education rules and recommends fees, while licenses are issued by the commissioner and the examination is given and administered by the commissioner — the Department of Labor and Industry, DLI, at every step. Restricted master and restricted journeyworker licenses are a closed grandfather class: no examination supports them as a route in, and there is no restricted-tier examination program.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Minnesota Master Plumber |
| Regulator | Commissioner of Labor and Industry; Minnesota Department of Labor and Industry (DLI). Minnesota Plumbing Board adopts the code and licensing/CE rules and recommends fees |
| Governing layers | Minn. Stat. ch. 326B; Minn. Rules ch. 4716 (licensing) and ch. 4714 (code) |
| Examination administrator | DLI (state-run). No third-party vendor |
| Examination format | 300 points / 5.5 hours. No question count is published, and none is stated on this page |
| Passing score | 70 percent — “the passing score for all examinations is 70%” |
| Application and examination fee | $50, separate from the license fee; nonrefundable |
| References in the room | Provided by DLI: 2020 Minnesota Plumbing Code, chapter 4714, a laws and rules booklet, and a calculator. Candidates do not supply their own materials |
| Tested code | 2020 Minnesota Plumbing Code (ch. 4714) — 2018 Uniform Plumbing Code with Minnesota amendments. Tested and adopted editions coincide |
| Approval | DLI approval is required before scheduling. There are no exceptions; walk-ins are not permitted |
| Administrator note | PassProfessor is independent and is not affiliated with the Minnesota Department of Labor and Industry or the Minnesota Plumbing Board |
Scored in points: read the Minnesota format correctly
Minnesota publishes its plumbing examinations in points, and accurate preparation starts by respecting that unit. The license examinations for the master plumbing license consist of 300 points. The journeyworker examination, by comparison, consists of 240 points. The time allowed to complete the master and journeyworker plumbers examination is 5.5 hours — the same duration for both tiers, and DLI’s schedule states the same figure for all plumbing exams.
No question count exists in the verified sources for either examination, and this page prints none; any source that converts 300 points into a number of questions is inventing the conversion. Unless stated otherwise, all questions have the same point value, and no partial points are given. Formats are predominantly multiple-choice, with two published variations: some calculation questions may not include multiple-choice answers, and some questions require more than one selection — where they do, that is identified and the number stated. The published sample calculation work covers water pipe sizing, DWV sizing, and storm water sizing, using chapter 6, chapters 7 and 9, and chapter 11 diagrams. That is calculation inside a written examination, with the department-provided code and calculator — not a hands-on practical, and no hands-on practical is published for this credential.
Tested and adopted: the 2020 Minnesota Plumbing Code
On the verified sources, the tested edition and the adopted edition coincide — but the name of the code must be given in full, because the short version misleads. The examination is based on the 2020 Minnesota Plumbing Code, Minnesota Rules chapter 4714. That code, effective December 17, 2021, incorporates by reference the 2018 edition of the Uniform Plumbing Code with Minnesota amendments: under Minn. R. 4714.0050, UPC chapters 2–11, 16, and 17 and appendices A, B, and I, as qualified by chapter 1300 and amended in chapter 4714. It replaced the 2015 Minnesota Plumbing Code.
Preparation must therefore compose on the 2020 Minnesota Plumbing Code — the 2018 UPC as amended by Minnesota — plus chapter 4716, chapter 1300, and Minn. Stat. chapter 326B, as the knowledge-area tables direct. Studying a bare 2018 UPC without the Minnesota amendments omits part of the tested instrument; studying the superseded 2015 code studies a replaced edition. The DLI guide adds a timing principle: the edition used is the edition adopted as part of the state building code at the time the examination is administered — the most current adopted edition at that time. Beyond the code chapter, the guide lists Minnesota Statutes chapters 144, 325, and 326/326B among the examination’s bases.
References are provided: the DLI room rule
Minnesota’s reference regime is the feature candidates most often misstate, so this page gives it in the verified formulation rather than a shorthand label. All reference materials and a calculator are provided by the department. No other materials or electronic devices, including cell phones, are allowed in the building.
Within the sitting, applicants are allowed to use the 2020 Minnesota Plumbing Code, chapter 4714, and an electronic calculator during their entire examination. The provided code copy does not include tabs or other aids. The provided calculator is a common desk type covering addition, subtraction, multiplication, division, square root, and percentage. The laws and rules booklet provided is current as of administration.
Three consequences follow. Candidates do not supply their own books: a personal annotated code stays outside. Navigation skill must transfer to an untabbed, unaided copy — locating provisions by structure rather than by personal markers. And calculation practice should use a basic desk calculator of the kind described. Describing this arrangement with a bare two-word label, without the provided-references formulation, would misdescribe it.
Who may sit: three routes to master eligibility
Approval comes before scheduling, absolutely: Minnesota’s published position allows no exceptions, and walk-ins are not permitted. A qualified applicant may schedule within one year after approval notification, with one reschedule only inside that year.
The master examination prerequisites offer three alternative routes; satisfying any one of them qualifies on this element. First, at least one year of practical plumbing experience as a licensed journeyworker plumber. Second, a current master plumber license from another state where the requirements are equivalent to Minnesota’s, as determined by the commissioner. Third, a current Minnesota restricted master plumber license together with five years of verifiable experience in business as a plumbing contractor in Minnesota.
Older reproductions of the licensing rule that state a longer journeyworker-experience requirement for master eligibility do not state the current verified prerequisite, and this page does not use them. Candidates should frame their applications on the three routes above.
Beneath the first route, a journeyworker candidate qualifies through at least four years of recorded practical experience as a registered apprentice or registered unlicensed plumber — one year counted as at least 1,750 hours, and, for the registered-unlicensed route, 2,000 hours in water distribution, 2,000 hours in DWV, and 1,000 hours in fixtures — or through the restricted-license route, or a qualifying out-of-state license. The minimum age to perform plumbing work and to be licensed or registered is 18. Testing takes place at DLI’s St. Paul office on Tuesdays, Wednesdays, and Thursdays, except in state-holiday weeks, and at outstate sites as listed by DLI. Results are mailed within two weeks and are not provided by telephone or email.
Fees, the license fee deadline, and the license term
The fee structure separates the examination from the license, in the statute’s own order. Under Minn. Stat. §326B.092, subdivision 1(a), the application for the initial license must be accompanied by an application and examination fee of $50, which is separate from the license fee. The license fee is due after the applicant passes the examination and before the license is issued. DLI’s published summary states the same figure as the $50 exam fee. Fees are nonrefundable.
After passing, the reconciled license figures are: master initial two-year license $88 ($80 base plus $8 board fee); renewal $93 ($88 plus a $5 continuing-education component); late fee $40. The applicant must pay the license fee within 180 days after notification of approval, or the commissioner will rescind the approval and deny the application. Master licenses expire December 31 of each even-numbered year; journeyworker licenses expire December 31 of each odd-numbered year. Renewal requires 16 hours of DLI-approved continuing education during the license period, for master, journeyworker, and restricted plumbers, at least eight hours of which must relate to the State Plumbing Code.
Retakes: the 30-day rule
Minnesota’s retake rule is explicit. Applicants who fail any examination are prohibited from retaking it for at least 30 days; the statute states the same interval from the application side — a denied applicant cannot submit a further application until at least 30 days after the failed examination. A failed applicant, and an applicant who fails to appear for a rescheduled exam, must submit a further application and examination fee before re-examination.
Examinations scoring within 1 percentage point of passing are rechecked. Written and oral reviews of individual examinations are not available, although written comment on specific questions is allowed. Candidates should treat the first sitting as the main event: the 30-day interval and the further application and fee make casual retesting slow and costly. Separately, a licensee who does not renew within two years must retake and pass the examination before a further license will be issued.
What the examination covers
Content is published as knowledge-area tables without per-area counts or percentages, and this program prints no invented blueprint weights. The published areas span: Basic Plumbing Principles; Conformance with Code; the chapter 2–6 topics of the code; Sanitary Drainage; Indirect Wastes; Vents; Traps and Interceptors; Storm Drainage; and nonpotable rainwater catchment — together with chapter 4716, chapter 1300, and miscellaneous statutes.
Read together, those areas join system knowledge to regulatory knowledge: sizing water, drainage, and storm systems from the code’s diagrams; handling vents, traps, interceptors, and indirect wastes as designed systems; and placing the work inside the licensing rules and statutes. The absence of published weights is itself guidance: balanced coverage, with sizing calculations practiced to fluency.
What the PassProfessor program will cover
The Minnesota code, amendments included. The program is built on the 2020 Minnesota Plumbing Code — chapter 4714, the 2018 UPC with Minnesota amendments — together with chapter 4716, chapter 1300, and Minn. Stat. chapter 326B, following the knowledge areas DLI publishes. Coverage never rests on a bare model code where a Minnesota amendment speaks.
Points-format practice, including the calculation work. Practice reflects the published format: predominantly multiple-choice work, sizing calculations worked from the code’s diagrams, and questions requiring more than one selection, identified as such. Pace is trained against the full sitting — 300 points in 5.5 hours — not against any invented item count.
Fluency in a provided, untabbed code. Because DLI provides the references and the provided copy carries no tabs or aids, the program trains location skill that transfers to a clean copy, and calculation work on a basic desk calculator.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with DLI or the Minnesota Plumbing Board. Completing this program confers no license or approval; DLI alone approves applicants, administers the examination, and issues licenses.
Tell me when enrollment opens. The Minnesota Master Plumber program is in the works as our catalog continues to expand, and enrollment is not yet open. Leave an email address and PassProfessor will write to you when the program is ready — and only about this program. The companion Minnesota Master Plumber Exam Guide at /minnesota-master-plumber-exam-guide/ works through eligibility, the code layer, and the sitting in fuller detail.
Frequently asked questions
Who issues the Minnesota Master Plumber license and gives the examination?
The Commissioner of Labor and Industry. Licenses are issued by the commissioner, and the examination is given and administered by the commissioner through the Minnesota Department of Labor and Industry. The Minnesota Plumbing Board adopts the Plumbing Code and licensing and continuing education rules and recommends fees.
Is there a testing vendor for the Minnesota examination?
No. The examination is state-run by DLI. Scheduling after approval, proctoring, reference provision, and scoring are all department functions.
How is the master examination scored, and how long does it last?
It consists of 300 points, with 5.5 hours allowed. The passing score for all examinations is 70 percent. Examinations scoring within 1 percentage point of passing are rechecked.
How many questions are on the examination?
No question count is published in the verified sources, and this page states none. Minnesota publishes the examination in points — 300 points for master, 240 points for journeyworker — and any conversion of points into a question count would be invented.
Which code is tested?
The 2020 Minnesota Plumbing Code, Minnesota Rules chapter 4714 — the 2018 Uniform Plumbing Code incorporated by reference with Minnesota amendments, effective December 17, 2021 — together with chapter 4716, chapter 1300, and the listed Minnesota Statutes layers. A bare 2018 UPC without the Minnesota amendments is not the tested instrument, and the superseded 2015 code is not either.
What references may a candidate use in the room?
Only the materials DLI provides: the 2020 Minnesota Plumbing Code, chapter 4714, a laws and rules booklet current as of administration, and a calculator — a common desk type — all provided by the department. Candidates do not supply their own materials, the provided code copy includes no tabs or other aids, and no other materials or electronic devices, including cell phones, are allowed in the building.
What experience qualifies a candidate for the master examination?
Any one of three routes: at least one year of practical plumbing experience as a licensed journeyworker plumber; or a current master plumber license from another state whose requirements are equivalent to Minnesota’s, as determined by the commissioner; or a current Minnesota restricted master plumber license with five years of verifiable experience in business as a plumbing contractor in Minnesota.
Must a candidate be approved before scheduling?
Yes, without exception. Walk-ins are not permitted. A qualified applicant may schedule within one year after the approval notification date, with one reschedule only inside that year.
What happens after a failed attempt?
Retaking is prohibited for at least 30 days after the failed examination. Re-examination requires a further application and examination fee. Results in any case are mailed within two weeks and are not provided by telephone or email.
Is PassProfessor affiliated with DLI?
No. PassProfessor is independent and is not affiliated with the Minnesota Department of Labor and Industry or the Minnesota Plumbing Board.
When does enrollment open?
The program is in the works and enrollment is not yet open. Leave an email address on this page and PassProfessor will write to you when the program is ready — and only about this program.