How to Become a Plumber in Maine

Five License Tiers, One Path Forward

Maine licenses plumbers through a tiered system managed by the Plumbers' Examining Board under the Office of Professional and Occupational Regulation (OPOR). The tiers are Trainee, Student Trainee, Journeyman-in-Training (JIT), Journeyman, and Master. Each has its own scope, and you advance by meeting the experience or education requirements for the pathway you use and passing any required trade exams.

There is no shortcut around the applicable experience or education requirements. Hours that count toward a credential must be documented and verified.

Step 1: Register as a Trainee

You can register as a Trainee Plumber at age 16 with no prior experience. The application goes through OPOR's online portal. You'll pay a $100 license fee plus a $21 criminal background check fee. If you're under 18, a parent or legal guardian must sign the application.

If you're enrolled in an approved plumbing program at a technical college, community college, or secondary career and technical education school, you can instead register as a Student Trainee — no fee, but you're only authorized to perform plumbing installations as part of your academic program.

Your license must show "Active" status before you do any plumbing work. Hours logged before your trainee registration is active don't count.

Step 2: Log Supervised Hours

As a Trainee, you work under the direct, on-site supervision of a licensed Journeyman or Master Plumber. "Direct supervision" means your supervisor is physically present on the job site — not available by phone, not in a different building.

You need either 4,000 hours (minimum two years) as a Trainee, or 2,000 hours as a JIT, to qualify for the Journeyman exam. The JIT pathway is available to graduates of approved one-year community college programs or two-year secondary technical programs.

Keep your own log of every shift. When it's time to apply for the exam, your supervising Master Plumber must sign a notarized Experience Affidavit confirming your hours. If that supervisor has moved on or closed their business by then, you'll have a serious documentation problem.

Step 3: Pass the Journeyman Exam

Submit the Journeyman Plumber Examination Application to the Board with your signed affidavits and any required transcripts. Once the Board approves your application, you'll receive an email with instructions for scheduling through Prov, Inc.

The exam is closed-book, and you need a 70% score to pass. Testing centers are in Auburn, Bangor, Calais, Portland, and Presque Isle, or you can use Prov's remote proctoring system. The exam fee ($65–$90) goes directly to Prov.

After passing, submit your final licensure application through OPOR with the $200 license fee and $21 background check fee.

Step 4: Advance to Master (Optional but Important)

A Journeyman license lets you perform installations and repairs, but you can't pull municipal permits, serve as the license of record on permitted projects, or run your own plumbing business. Those functions require a Master Plumber license.

Master qualification requires either 2,000 additional hours (minimum one year) as a licensed Journeyman, or 8,000 total hours (minimum four years) as a Trainee under a Master — the direct-to-Master path.

The Master exam requires a 75% passing score. Same application process: Board approval, Prov scheduling, and final licensure through OPOR.

Step 5: Handle Business and Municipal Layers

Holding a Master license authorizes your individual competency. Operating a business requires additional steps: registering your entity with the Maine Secretary of State, setting up tax accounts with Maine Revenue Services, and carrying Workers' Compensation insurance if you have any employees.

Before starting any permitted plumbing project, you'll pull a permit from the local municipality — the process varies significantly from Portland's CSS online portal to small towns where the plumbing inspector keeps limited monthly hours.

The Maine Plumber License Guide covers the full sequence from trainee registration through business formation and municipal permitting, with checklists for each stage.

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