Maine’s Master Plumber examination, administered by Prov, Inc. for the Maine Plumbers’ Examining Board to Board-approved candidates only, is a closed-book, computer-based sitting of 100 questions in 3 hours, scored against a cutscore of 75 percent and keyed to the Uniform Plumbing Code 2015, in a state whose installation standard has been the 2021 Uniform Plumbing Code since January 1, 2022. The PassProfessor Maine Master Plumber program, described on the companion Maine Master Plumber Exam Preparation page, prepares candidates for that sitting.
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The credential at a glance
| Item | Verified position |
|---|---|
| Credential | Maine Master Plumber |
| Regulator | Maine Plumbers’ Examining Board, Office of Professional and Occupational Regulation, Department of Professional and Financial Regulation; 32 M.R.S. Chapter 49 (§§3301–3507); Board Rules 02-395 C.M.R. |
| Administrator | Prov, Inc.; Board approval required before scheduling — scores without prior approval are null and void; Prov facilities nationwide or remote delivery via Prov Examroom; bulletin of record MOPOR-2023.08.21 |
| Structure | 100 questions / 3 hours / CLOSED BOOK / computer-based |
| In-room material | Proctor-provided Maine Plumbing Tables 2015 UPC printout only; no candidate books; simple 4-function calculator approved |
| Passing standard | 75 percent — statute, bulletin cutscore, and Board guidance agree |
| Tested edition | Uniform Plumbing Code 2015 (IAPMO) |
| Adopted edition | 2021 Uniform Plumbing Code — Board Rule 02-395 Chapter 4, effective January 1, 2022; tested and adopted are different layers |
| Examination fee | $65 to Prov at scheduling |
| Eligibility routes | At least 1 year / 2,000 hours as a licensed journeyman plumber, OR at least 4 years / 8,000 hours as a licensed trainee plumber under a licensed master plumber (or equivalent) |
| Practical component | None published — closed-book written examination only |
| Administrator note | PassProfessor is independent and is not affiliated with the Maine Plumbers’ Examining Board, OPOR, or Prov, Inc. |
Three facts that organise everything else
A candidate can know a great deal about Maine plumbing and still prepare wrongly for this examination by missing one of three structural facts. This guide returns to them throughout, because each one reverses a common assumption.
The room is closed. Every plumber examination in the Maine bulletin is delivered in closed-book format, and no reference is marked as permitted for candidates to bring. The study references exist — they define what to learn — but they stay outside the room. The one exception is not candidate-supplied at all: the proctor provides a printout of the Maine Plumbing Tables 2015 UPC at the testing site, and candidate printed versions of those same tables are expressly not allowed.
The standard is 75 percent, in three voices. Maine statute states the floor directly: the passing grade on a master plumber license examination may not be less than 75 percent. The bulletin’s results reporting states the operational form: the Master Plumber exam requires a 75% passing score and will be scored and graded against a cutscore of 75%. The Board’s guidance to master candidates states it in plain words: you must get 75% correct in order to pass. Journeyman candidates work to a 70 percent floor in the same sources; master candidates should not carry that number upward with them.
The book is 2015; the building is 2021. The examination is keyed to the Uniform Plumbing Code 2015. Maine adopted the 2021 Uniform Plumbing Code as its installation standard by Board rule effective January 1, 2022. Both statements are true at once, in different layers, and the candidate’s working life runs in the newer layer while the candidate’s examination runs in the older one. Holding the layers apart is a study skill this guide treats as examinable in itself.
The route, step by step
Step one — qualify on one of the two routes. Route one: at least one year with 2,000 hours of work in the field of plumbing installations as a licensed journeyman plumber. Route two: at least four years with 8,000 hours of work in the field of plumbing installations as a licensed trainee plumber under the supervision of a licensed master plumber, or the equivalent. The routes are alternatives, not stages; the trainee route reaches the master examination without first holding the journeyman license.
Step two — apply through the Board’s online system and obtain approval. Since January 1, 2024, all license, examination, and renewal applications must use the Board’s online system. Approval is not a formality: Board approval is required before scheduling or sitting, and scores obtained without prior Board approval are null and void.
Step three — schedule with Prov and sit. Prov delivers the examination by computer at its facilities nationwide or remotely through Prov Examroom. The fee at scheduling is $65.
Step four — meet the cutscore. One hundred questions, three hours, 75 percent, closed book, with the proctor’s tables printout and an approved simple calculator as the only aids.
Step five — license inside the window. Board approval remains valid for two years at the rule layer: an applicant who does not pass within that time, or who does not apply for licensure within two years of notification of a passing score, must reapply as a new applicant and retake the examination. The license term is two years.
For ladder context, the journeyman examination beneath this one is 80 questions in 3 hours, also closed book, resting on a qualification of at least two years and 4,000 hours as a licensed trainee under a master, or 2,000 hours as a journeyman-in-training within four years of that licensure. The master paper’s extra twenty questions and five-point-higher standard are the visible part of the step up; the eligibility routes and the regulations weight are the rest of it.
Eligibility in depth: hours, supervision, and the approval window
Maine’s two routes reward different careers, and candidates should identify theirs early because the documentation differs. The journeyman route documents licensed journeyman work: the year and the 2,000 hours must be work in the field of plumbing installations in that licensed capacity. The trainee route documents supervised formation at greater length: four years and 8,000 hours as a licensed trainee under a licensed master’s supervision. In both routes the words “licensed” and the stated hours are the substance; unlicensed time and approximated hours are where applications stall.
The approval window then governs the examination campaign as a whole. Two years is generous for a single sitting and unforgiving for an indefinite one: a candidate who passes must still apply for licensure within two years of the passing notification, and a candidate who has not passed within the approval period starts again as a new applicant, examination included. Sensible candidates schedule the first sitting early enough in the window that the bulletin’s retake freedom — retakes as often as necessary inside the window — remains a real resource rather than a theoretical one.
Tested and adopted: studying a code the state has already succeeded
The bulletin reference list defines the tested world completely. For both journeyman and master candidates it names Maine Plumbing Laws and Rules, 2016; the Maine Plumbing Tables 2015 UPC; Plumbing Basics for Contractors, 3rd Edition, 2014; and the Uniform Plumbing Code 2015. Nothing else is an examination reference: no later UPC edition appears, no other model plumbing code appears, and the adopted code appears only in its proper layer — as the installation standard.
That adopted standard deserves its own precise statement. Board Rule 02-395 Chapter 4 adopted the 2021 Uniform Plumbing Code, effective January 1, 2022, as the standard for plumbing installations in Maine, subject to the chapter’s exclusions and amendments. A working Maine master therefore designs, installs, and answers for work under the 2021 code daily. The examination risk is subtle and specific: not ignorance, but interference — the newer provision arriving in memory first, fluently, and wrong for the room the candidate is sitting in. The cure is equally specific. Study the 2015 text as the operative text. Where a provision is known to differ in current practice, learn the pair consciously, tagged by layer, rather than allowing the two to merge into a single undated recollection. Candidates who build that tagging habit find the edition gap manageable; candidates who simply “study plumbing” walk into it repeatedly across 100 questions.
The outline in full: a regulations-and-systems paper
The master outline sums to 100 questions.
Drainage, Waste, Sanitary Venting — 20 questions. The largest block treats drainage and venting as one system: waste flow, vent protection of trap seals, sizing, and the configurations the 2015 code permits and forbids. In a closed-book room these items test internalised system logic — the candidate must reconstruct why a configuration works, not find the table that blesses it — supported only by the provided tables printout where sizing values are needed.
General Regulations — 18 questions. Nearly one question in five examines the legal frame: the licensing law, the Board’s rules, and the duties of the licensee. This is the block that most distinguishes a master paper from a journeyman paper, and the block least forgiving of closed-book conditions, because regulatory detail is precisely what experienced tradespeople are accustomed to looking up. Preparation must convert the Maine laws and rules from reference material into recitable knowledge: definitions, license duties, and the requirements that govern how work may be offered, supervised, and performed.
Water Supply Systems Including Backflow Prevention and Water Heaters — 18 questions. Supply sizing, distribution, cross-connection protection, and water heating in a single combined block. The combination is itself instructive — Maine examines the potable system whole, so a candidate’s backflow knowledge is tested inside supply scenarios rather than in isolation.
General Knowledge — 16 questions. The broad trade foundation: materials, methods, safety, and the general practice knowledge the other blocks assume.
Plumbing Fixtures — 8 questions; Traps and Interceptors — 6 questions; Indirect Waste — 6 questions. The mid-weight blocks examine fixture requirements and counts, trap rules and interceptor practice, and the air-gap logic of indirect waste — areas where precise code detail decides individual questions and where closed-book recall of specific requirements earns its keep.
Specialty Venting — 4 questions; Roof Drainage — 4 questions. The smallest blocks cover venting methods beyond the standard system and the sizing and arrangement of roof drainage. Four questions each is small until the arithmetic of a 75 percent standard is applied: a candidate can miss no more than 25 questions in total, and neglecting two small blocks outright spends eight of them before the large blocks are attempted.
No hands-on practical, drawing portion, or takeoff component is published for this credential; the examination as published is the closed-book written sitting described here, and preparation belongs entirely to it. The sources likewise state nothing about unscored or experimental items for this examination, and this guide states nothing either way.
The sitting itself: pace, the tables, and the calculator
Three hours for 100 closed-book questions is a pace of 108 seconds per question. There is no retrieval time to manage, as in an open-book sitting; there is instead a recall discipline to maintain. Questions the candidate knows must be answered at first-reading speed so that calculation and system-design questions can take the time they need. The tables printout should be treated as a precision instrument with a narrow job: sizing values and tabulated data for the questions that require them. Candidates who have practised with the Maine Plumbing Tables during study will use the printout in seconds; candidates meeting the tables for the first time in the room will spend their margin learning a document instead of answering questions.
The calculator rule is narrow and worth noting exactly: a simple 4-function calculator is an approved item under the bulletin, while personal digital assistants, tablets, cell phones, and special calculators are not permitted. Practise the examination’s arithmetic on that class of tool, not on a phone or a programmable calculator whose absence on the day would disturb settled habits.
Remote delivery through Prov Examroom and in-person delivery at Prov facilities follow the same examination: computer-based, closed book, with results provided at the testing centre on completion for in-person sittings and available online around the clock through the Prov account.
Fees in their layers, and the mechanics around the result
The examination fee is $65, shown in the bulletin’s fee table for the Master Plumber examination and paid to Prov at scheduling. Each retake is a new scheduled, paid examination at the same figure. This guide prints no distinct Board examination-application dollar figure, because the sources require such a fee by reference without stating its amount; candidates should take the current figure from the Board’s online application itself rather than from any secondary source.
The license layer, kept separate from examination charges, is published as follows: master license fee $200.00, criminal background check fee $21.00, biennial renewal $200.00, and a late fee of $50.00 up to 90 days. Those figures belong to licensure and background screening; none of them is an examination application fee, and they should not be budgeted or described as one.
Retakes follow the bulletin’s own sentence: failed plumber examinations can be retaken as often as is necessary during the two-year window. No minimum interval between attempts is stated in any primary source retrieved for this guide, and no attempt cap applies on those sources — a numerical cap circulating in secondary material is not supported and is not used here. The one hard boundary runs the other way: candidates cannot retake an examination once they have passed it. Cancellation and rescheduling require contact with Prov at least three business days before the test date; rescheduling by that deadline is free, and a no-show or late cancellation forfeits the examination fee.
Renewal carries no continuing education requirement: none was found in the licensing statute, the Board’s renewal rule as read, or the Board’s renewal pages. The master’s ongoing obligations are the license term, the renewal fee, and the regulatory duties the General Regulations block examines — not an hours cycle.
A study plan for a closed-book, 2015-keyed, 75 percent examination
Phase one — the 2015 code as the operative text. Read and learn the Uniform Plumbing Code 2015 as the law of the examination, building the tables fluency described above alongside it. Keep a running two-layer notebook for every provision where current 2021 installation practice differs, tagged tested versus adopted.
Phase two — regulations to recitation. Work the Maine plumbing laws and rules until the duties can be stated without the book: 18 questions, nearly a fifth of the paper, depend on exactly that conversion.
Phase three — systems at depth. Drainage and venting as one system; supply, backflow, and water heating as another. Practise sizing and configuration problems at examination pace, with only the tables as an aid, until the standard problem families resolve without hesitation.
Phase four — the supporting blocks. Fixtures, traps and interceptors, indirect waste, specialty venting, roof drainage, and general knowledge, studied to precision rather than coverage: on a 75 percent standard, small blocks are not optional blocks.
Phase five — closed-book rehearsal under the real clock. Full 100-question practice in three hours, nothing on the desk but a tables printout and a simple calculator, scored by outline block, with every miss sorted into one of three cures: knowledge not yet learned, a 2021-layer answer given to a 2015 question, or pace failure on a question the candidate actually knew. The companion Maine Master Plumber Exam Preparation page describes how the PassProfessor program in preparation organises this work; enrollment is not yet open, and candidates may leave an email address there or below to be notified.
Frequently asked questions
Closed book — does that really mean no code book at all?
Yes. No candidate books are allowed in the room and no reference is marked permitted. The only material supplied is the proctor-provided printout of the Maine Plumbing Tables 2015 UPC.
Why does the proctor provide the tables if the exam is closed book?
Because the tables are the defined exception: candidate printed versions are not allowed, and the testing site provides the printout. Everything else is examined from knowledge.
What exactly must I score to pass?
75 percent. The statute sets the floor at no less than 75%, the bulletin scores the Master Plumber exam against a cutscore of 75%, and Board guidance states the same figure.
The journeyman standard is lower, is it not?
Yes — the journeyman floor in the same sources is 70 percent. Do not carry it into the master room.
Which UPC edition should I study?
The 2015 edition, with the bulletin’s full study list: Maine Plumbing Laws and Rules, 2016; the Maine Plumbing Tables 2015 UPC; Plumbing Basics for Contractors, 3rd Edition, 2014; and the Uniform Plumbing Code 2015.
Maine installs under the 2021 UPC. Does that change the examination?
No. The 2021 code is the installation standard adopted effective January 1, 2022. It is not the examination basis, and neither is the 2018 edition.
Do I need Board approval before I schedule?
Yes. Approval precedes scheduling, applications run through the Board’s online system, and scores obtained without prior approval are null and void.
I never held a journeyman license. Can I still reach the Master examination?
Yes, on the trainee route: at least four years with 8,000 hours as a licensed trainee plumber under a licensed master plumber, or the equivalent.
How long is my approval good for?
Two years at the rule layer — pass within it, and apply for licensure within two years of passing notification, or reapply as a new applicant and retake.
How many times can I retake a failed examination?
As often as is necessary during the two-year window, at $65 per scheduled attempt. No minimum interval is stated in the primary sources.
What calculator may I use?
A simple 4-function calculator is approved. Phones, tablets, personal digital assistants, and special calculators are not permitted.
Is continuing education required to renew?
No continuing education requirement for plumber renewal was found in the statute, the Board’s rules, or the Board’s renewal pages.
Is PassProfessor affiliated with the Board or Prov?
No. PassProfessor is an independent preparation provider, not affiliated with the Maine Plumbers’ Examining Board, the Office of Professional and Occupational Regulation, or Prov, Inc. The Board alone licenses and approves candidates.
When does enrollment open for the PassProfessor program?
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.