Plumbing Contractor License in Maine: Requirements, Qualifier, Bond and Exams
Statewide — but not as a company credential.
Maine has no separate plumbing contractor license: the Master Plumber license is the license to engage in the business of installing plumbing, and plumbing work needs a state license from the Plumbers' Examining Board (homeowners on their own single-family residence are exempt); municipalities may not add their own.
A master needs 1 year and 2,000 hours as a licensed journeyman, or 4 years and 8,000 hours as a licensed trainee under a master, plus at least 75% on the master exam.
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At a glance
Yes, through a person: Maine has no separate plumbing contractor license, and the Master Plumber license is the license to engage in the business of installing plumbing.
The Plumbers' Examining Board.
It licenses individuals doing plumbing — homeowners working on their own single-family residence are exempt — and municipalities may not require their own plumbing licenses.
Individual only: Trainee Plumber, Journeyman-in-Training, Journeyman Plumber and Master Plumber.
No business classes — no separate business license exists.
The licensed Master Plumber: 1 year and 2,000 hours as a licensed journeyman, or 4 years and 8,000 hours as a licensed trainee under a master, plus at least 75% on the master exam.
The individual plumber exams: 70% to pass journeyman, at least 75% for master.
No business-and-law exam in our research; the exam vendor was not captured.
Not established in our research — ask the board.
The Maine sources we read state no bond amount or insurance minimum for plumbing businesses.
Master Plumber: $200 plus a $21 background check, renewed every two years at a $200 renewal fee, with a $50 late fee up to 90 days after expiry.
Trainee Plumber: $100.
Statute allows licenses by reciprocity where another state's standards and experience are at least equivalent to Maine's and it grants similar privileges to Maine licensees; no partner list was found.
The Maine plumbing license ladder
- Trainee PlumberEntry level
The $100, no-exam entry license: a trainee assists and makes plumbing installations under a journeyman or master's direct supervision, and must be employed by a licensed master plumber or an entity employing one.
- Journeyman-in-TrainingJourneyman
A $200 license, valid for a single nonrenewable 4-year term and issued only once: for people who completed one year of plumbing school, a two-year high-school CTE program or a registered DOL apprenticeship program and passed the journeyman exam, and who become journeymen after 2,000 hours under a master within that term.
- Journeyman PlumberJourneyman
The working license: at least 2 years and 4,000 hours as a licensed trainee under a master plumber (or a school route), a 70% exam pass, $200 plus a $21 background check, renewed every two years.
- Master PlumberMaster
The license to engage in the business of installing plumbing — Maine's contractor credential, held by a person: 1 year and 2,000 hours as a licensed journeyman, or 4 years and 8,000 hours as a licensed trainee under a master, plus at least 75% on the master exam.
Does Maine license plumbing contractors statewide, or only locally?
Both answers are true at once, and the shape matters.
Maine requires a state license for any individual who is engaged in plumbing or performing plumbing installations, issued by the Plumbers' Examining Board — homeowners working on their own single-family residence are the exemption — and a municipality may not require plumbers to be municipally licensed, so licensing is statewide rather than local.
On the business side, there is no separate plumbing contractor license for a company to register under.
The Master Plumber license is the license to engage in the business of installing plumbing or plumbing systems, so a contracting business stands on the master plumber who holds it — the owner, or a company that employs a master plumber, the employment shape Maine's trainee rule confirms.
Set that structure up with the board before you take your first contract.
“A Master Plumber means any person licensed by the Board, to engage in, or about to engage in, the business of installing plumbing or plumbing systems.”
Which agency issues the license, and what are the classes?
One board issues everything: the Plumbers' Examining Board.
Its classes are all individual — Trainee Plumber (issued without an exam), Journeyman-in-Training, Journeyman Plumber and Master Plumber — and there are no business classes, because there is no business license to class.
The old statute section covering corporations, firms and partnerships is repealed, and the board's license list our research read shows no company entry.
Every class covers a person, so what your company can do in plumbing is what its licensed people hold.
Who can be the qualifier, and what experience do they need?
The board's license list we read shows no company license, and we found no qualifier filing — the qualification that matters is the license itself: the Master Plumber license, held by a person.
A master applicant needs at least 1 year and 2,000 hours of experience as a licensed journeyman plumber, or at least 4 years and 8,000 hours as a licensed trainee under a master.
If you hold the master license, your own license carries the business; if you do not, the practical route is an entity that employs a master — the same employment shape Maine's trainee rule already uses.
HVACHires' guide to the contractor license qualifier explains the role a qualifier plays in the states that do require one.
“The passing grade on a master plumber license examination may not be less than 75%.”
Which exams must be passed: trade, and business and law?
The exams on record are the individual plumber exams, and your qualifier's is the master exam: the passing grade may not be less than 75%.
The journeyman exam underneath takes a 70% passing score, and to qualify for it an applicant needs at least 2 years and 4,000 hours as a licensed trainee under a master plumber, or completion of a Maine two-year high school CTE plumbing program, or a one-year community-college plumbing program.
We found no trade exam for the business itself and no business-and-law exam — with no company license in our research, there is no exam attached to one.
Which vendor administers the exams, and which plumbing code edition Maine is on, our research did not capture; the board's examination page is the place to check before you book.
What bond and insurance are required?
This is a gap in our research, not a confirmed absence.
The Maine sources we read state no bond amount and no insurance minimum for plumbing businesses, and Maine's licensing is individual-only, so there is no company license for a bond requirement to attach to.
We will not guess at a figure: ask the Plumbers' Examining Board what it currently requires, put liability coverage questions to your insurance agent, and check whether the municipality where you work adds anything.
HVACHires' separate guide to contractor license bonds and insurance explains how these instruments work where a state or city does require one.
What does it cost, and how often is it renewed?
The license behind the business is the Master Plumber license: $200 plus a $21 criminal background check, renewed every two years at a $200 renewal fee, with a $50 late fee assessed for licenses renewed up to 90 days after the license expiration date.
There is no separate company license fee, because there is no separate company license.
The crew's licenses run on the same board: a Trainee Plumber license costs $100 plus the $21 background check and renews every two years, the Journeyman-in-Training license is $200 for its single nonrenewable 4-year term, and a journeyman license is $200 like a master's.
On continuing education our research did not confirm a requirement either way — the renewal application we read contained no CE requirement, and the board's rules chapters were outside our research — so ask the board before you plan renewal hours.
Does Maine have reciprocity with other states?
Maine's plumbing statute authorizes licenses by reciprocity for plumbers licensed in other states, on two conditions: the other state's licensing standards and experience requirements must be at least equivalent to Maine's, and that state must grant similar privileges to persons licensed under Maine's chapter.
No list of reciprocal states was found in our research, so treat your case individually and ask the board.
The examination application our research read also gives out-of-state applicants another route — what it calls the 4th journeyman / 3rd master exam pathway.
For the business, reciprocity flows through the person as everything else does: an out-of-state master who wants to carry a Maine plumbing company first needs the Maine Master Plumber license.
What happens if your qualifier leaves?
We found no qualifier of record for Maine plumbing companies: the license list we read shows no company license, and we found no qualifier filing, so we saw nothing that needs re-filing.
The business's license is the master plumber's own, and our research found no rule covering the departure: no notice requirement and no replacement window appear in the sources we read (a gap in our research, not a clearance — ask the board how it treats a company whose master leaves).
What is on the record is supervision and employment: a master or journeyman plumber may not have more than 3 trainee plumbers working under their direct supervision, and a trainee must be employed by a licensed master plumber or an entity employing one.
If your only master is leaving, ask the board how it treats a company employing trainees in that gap — and recruit or promote before the resignation lands.
What contract rules apply to residential plumbing work in Maine?
One contract rule sits outside licensing: any home construction contract for more than $3,000 in materials or labor must be in writing and must be signed by both the home construction contractor and the homeowner or lessee.
That is Maine's home-construction contract statute, not a Plumbers' Examining Board rule.
Read the current statute and its definitions before you change your proposal templates.
“Any home construction contract for more than $3,000 in materials or labor must be in writing and must be signed by both the home construction contractor and the homeowner or lessee.”
What This Page Does, and Doesn’t, Cover
This page summarizes the Maine board pages, statutes, rules and other sources listed below, as read for this state-by-state plumbing contractor licensing series, current as of September 2026.
It is not a substitute for the instructions the Plumbers' Examining Board publishes.
For the rest of the picture in Maine, see HVAC contractor licensing in Maine and plumbing licensing in Maine.
Frequently Asked Questions
Does a plumbing company need a license in Maine?
Not a company license: Maine issues no separate plumbing contractor license.
The Master Plumber license is the license defined to engage in the business of installing plumbing, and individuals doing plumbing need a state license from the Plumbers' Examining Board — homeowners working on their own single-family residence are exempt — and municipalities may not add their own.
In practice a company operates through a licensed master plumber: the owner, or an entity that employs one.
Confirm your structure with the board before you register the business.
How do you become a Master Plumber in Maine?
Two experience routes: at least 1 year and 2,000 hours as a licensed journeyman plumber, or at least 4 years and 8,000 hours as a licensed trainee under a master.
You must then score at least 75% on the master plumber license examination.
The license costs $200 plus a $21 criminal background check and renews every two years at $200.
Journeyman licensure underneath takes at least 2 years and 4,000 hours as a licensed trainee and a 70% exam pass.
How many apprentices can a Maine master plumber supervise?
Three.
A master or journeyman plumber may not have more than 3 trainee plumbers working under the master or journeyman plumber's direct supervision, and each trainee must be employed by a licensed master plumber or an entity employing one.
For a growing company the cap matters twice: it limits how many trainees each licensed person can carry, and it depends on that licensed person staying.
Is there a bond requirement for Maine plumbing contractors?
Our research did not find one.
The Maine sources we read state no bond amount and no insurance minimum for plumbing businesses, and Maine's plumbing licensing is individual-only — that is a gap in our research, not a confirmed absence.
Ask the board what it currently requires, and put liability questions to your insurance agent, before you bid.
Do Maine plumber licenses require continuing education?
We did not find a CE requirement.
The renewal application we read contained no continuing-education requirement, and the board's rules chapters were outside our research, so we cannot confirm the question either way.
Ask the Plumbers' Examining Board before you plan renewal, and confirm the current fee schedule at the same time.
More Maine Resources
Sources
- Plumbers' Examining Board: Individual Licenses (retrieved 2026-09-29)
- 32 MRSA §3302 (plumbing licenses; municipal licensing barred) (retrieved 2026-09-29)
- 32 MRSA §3501 (trainee and journeyman-in-training licenses) (retrieved 2026-09-29)
- 32 MRSA §3501-A (examinations and passing grades) (retrieved 2026-09-29)
- 32 MRSA §3504-A (licenses by reciprocity) (retrieved 2026-09-29)
- Plumbers' Examining Board: Journeyman/Master examination application (retrieved 2026-09-29)
- Plumbers' Examining Board: Plumber license renewal application (retrieved 2026-09-29)
- Plumbers' Examining Board: Examinations (retrieved 2026-09-29)
- 10 MRSA §1487 (home construction contracts) (retrieved 2026-09-29)
Sourced from the documents listed above.
Verified September 2026.
This is career information, not legal advice.
Confirm current rules with the Plumbers' Examining Board.