Maryland Master Plumber License Requirements (2026)

The Maryland State Board of Plumbing licenses apprentice, journey, master, limited, and gas-fitting credentials. The standard statewide path is Apprentice Plumber/Gas Fitter to Journey Plumber/Gas Fitter to Master Plumber/Gas Fitter. A journey applicant needs four years as an apprentice, 7,500 supervised training hours, and approved 32-hour backflow-prevention training; a master applicant needs two years as a journey plumber and 3,750 additional supervised hours, then the PSI examination. The Master Plumber/Gas Fitter license includes plumbing and natural-gas services. State plumbing licenses are required statewide except Baltimore County and the areas served by WSSC, which issue their own licenses and use their own plumbing code.

Regulatory Body

Maryland State Board of Plumbing — Department of Labor (Maryland Plumbing Board) is the statutory authority responsible for issuing and enforcing this license under Md. Code, Business Occupations and Professions Title 12; COMAR 09.20. Licenses and regulates plumbing and gas-service individuals statewide, subject to the Baltimore County and WSSC exceptions.

Official portal: https://www.labor.maryland.gov/license/pl/
Address: 100 S. Charles Street, Tower I, Baltimore, MD 21201
Phone: (410) 230-6379

Eligibility Requirements

Applicants must be at least 16 years old. Applicants must provide a Social Security Number. No Maryland residency requirement.

Good moral character

A felony or misdemeanor does not automatically disqualify an applicant. The Board evaluates convictions case by case and may require court records and the applicant’s explanation.

Background investigation

Follow the current online application’s disclosure instructions. The Board’s published licensing FAQ describes conviction records and explanations when applicable, rather than a universal fingerprint prerequisite.

Experience and Education

At least 6 years of for the standard master path: four years as an apprentice with 7,500 supervised training hours and approved 32-hour backflow-prevention training for the journey examination, followed by two years as a journey plumber and 3,750 additional supervised hours for the master examination has to be evidenced and confirmed. Retain payroll, tax, project, or supervisor records, since the board may audit the experience claimed.

Accepted proof of experience or eligibility

Proof of qualifying supervised hours and current/previous license history uploaded to PSI for examination eligibility
Approved 32-hour backflow-prevention-device-testing certification
For the master examination, experience certification covering 3,750 hours as a licensed journey plumber under a master plumber
Photo identification and any current verification documents required by PSI or the Board

Education substitution

The Board may allow up to 1,500 hours of accredited, approved school study toward the journey experience requirement. Confirm approval before counting coursework.

Exam Requirements

Testing provider or authority: PSI Services LLC for the Maryland State Board of Plumbing. The following examination requirements cover the pathways described in this guide; follow each part's classification, waiver, and local-scope conditions. Unpublished format details do not remove an examination requirement:

Maryland Master Plumber/Gas Fitter examination — 100 questions, 240 minutes, passing score 70%

Examination fee: $65 for the Master Plumber/Gas Fitter examination, paid to PSI.

Retake policy: The PSI examination-registration fee is nonrefundable, nontransferable, and valid for one examination for one year. Re-register and pay the current fee after a failed or forfeited appointment.

Insurance and Bonds

There is no statewide surety bond tied to this credential in the cited record. Bonding can still surface at the project level — permit, license, or public-works bonds — so check before you bid.

General liability

When contracting in the licensee’s name or another person’s name, the Board requires at least $300,000 general liability plus $100,000 property-damage coverage per occurrence ($400,000 combined). The individual licensee must appear on the certificate; umbrella coverage does not satisfy this Board requirement.

Workers' compensation

Workers’ compensation is a separate Maryland employment-law question. Confirm coverage or any valid exemption for the business; the Plumbing Board’s contracting insurance requirement is distinct.

Additional financial requirements

No financial statement requirement.

Fee Schedule

Fee	Amount
Application	$87.50
Examination	$65
Initial license	No separate amount recorded; confirm in the fee guidance
Renewal (every 2 years)	$87.50

To turn these board fees into a realistic year-one budget — bond premium, liability insurance, and exam prep included — open the cost calculator preloaded for Maryland plumber.

Renewal and Continuing Education

The Maryland Master Plumber/Gas Fitter must be renewed every 2 years. The fee to renew is presently $87.50. State plumbing licenses renew for two years and expire on the first May 1 in an odd-numbered year. A license that remains lapsed for more than four years requires a new application and the appropriate examination. The Board’s published eight-hours-per-calendar-year CE requirement applies to plumbing inspectors only.

Downloadable Asset

2026 Maryland Plumber License Roadmap (PDF) — a printable step-by-step checklist for the application process.

Download the PDF roadmap →

Reciprocity

Maryland grants no NASCLA reciprocity for this classification.

Reciprocal State	Accepted Exam	Conditions
Delaware	Master Plumber/Gas Fitter reciprocal license	The Board lists Delaware reciprocity for the Master Plumber/Gas Fitter license only; submit the current verification and insurance documents.

The Board also describes reciprocal paths from Baltimore County and WSSC for qualifying plumbing-and-gas credentials, and like natural-gas-fitter paths from those local authorities. Do not treat Virginia or West Virginia as Board reciprocity partners without written Board confirmation.

Weighing more than one jurisdiction? The national hub compares published Plumber license requirements by state — exam, bond, fee, and experience thresholds side by side.

Plumber Licensing in Neighboring States

Contractors working near a state line, or weighing where to qualify first, should compare Maryland's requirements against the bordering jurisdictions before committing to an application:

Delaware Plumber License Requirements — Delaware Master Plumber License
District of Columbia Plumber License Requirements — DC Master Plumber/Gasfitter and Journeyman Plumber
Pennsylvania Plumber License Requirements — Pennsylvania Plumber — Local Licensing; No Statewide Trade License
Virginia Plumber License Requirements — Virginia Master Plumber Tradesman License
West Virginia Plumber License Requirements — West Virginia Master Plumber (and Journeyman Plumber)

Step-by-Step Application Roadmap

Confirm the licensing jurisdiction. Maryland state plumbing licensing applies except in Baltimore County and the WSSC service area, which administer their own credentials and code. Confirm the project jurisdiction first.
Hold the apprentice credential and document training. For the standard journey path, hold the apprentice license for four years, complete 7,500 supervised hours, and complete Board-approved 32-hour backflow-prevention training.
Pass the Journey Plumber/Gas Fitter examination. Apply to PSI, upload qualifying proof, pass the current examination, then complete the Board’s original-license process.
Complete master-level journey experience. Hold the journey license for at least two years and document 3,750 hours of plumbing training under a licensed master plumber.
Pass the Master Plumber/Gas Fitter examination. The current PSI master examination has 100 questions, a 70% passing score, and a 240-minute time limit.
File for the state license and contracting insurance. After passing, apply to the Board and provide the required insurance if you will contract for plumbing services. Keep the licensed individual named on the certificate.

Application Checklist

Before submitting to Maryland Plumbing Board, the applicant should have each of the following ready:

Correct state or local jurisdiction confirmed (state Board, Baltimore County, or WSSC)
Apprentice and journey license history, including 7,500 supervised apprentice hours
Approved 32-hour backflow-prevention-device-testing certification
At least two years as a journey plumber and 3,750 supervised journey hours
PSI Master Plumber/Gas Fitter examination pass result (70% or higher)
Board original-license application and current $87.50 license fee
$300,000 general liability plus $100,000 property-damage insurance certificate if contracting

Common Filing Mistakes

The errors below are the ones that most frequently cost Maryland Plumber applicants time, drawn from the cited board guidance.

Skipping apprentice registration

The standard journey path requires four years as an apprentice and 7,500 supervised hours. Keep the records required for PSI review and do not count unsupervised work.

Letting the journey license lapse before the master exam

The master path requires both at least two years as a journey plumber and 3,750 supervised journey hours. Retain the current license history and experience verification.

Treating gas fitting as a separate master endorsement

Maryland’s standard credential is Master Plumber/Gas Fitter; it includes plumbing and natural-gas services. Separate natural-gas-fitter credentials are available for qualified non-plumbers.

Underestimating the apprenticeship hours

The journey step also needs approved 32-hour backflow-prevention training. Do not confuse that course with the later 3,750-hour master experience requirement.

Applying to the wrong licensing authority

Baltimore County and the WSSC service area have their own plumbing licenses and code. Confirm the project’s jurisdiction before relying on a Maryland state credential or filing an application.

Study and Reference Materials

The following references are cited by the regulator, used in the application process, or commonly used to prepare for the trade scope. Listed for reader convenience; CLR receives no compensation for these recommendations.

Maryland PSI Plumber/Gas Fitter Candidate Information Bulletin — PSI / Maryland State Board of Plumbing. Official source for eligibility documents, current exam format, fee, references, and scheduling.
Maryland Board of Plumbing license requirements and FAQ — Maryland Department of Labor. Use for the apprentice, journey, master, insurance, and reciprocity rules.
Md. Code, Business Occupations §12-101 et seq. and COMAR 09.20 — State of Maryland. Licensing law and rules.

Other Maryland Trade Licenses

For a different Maryland credential, see these companion guides published by CLR:

Frequently Asked Questions

What are the Maryland plumbing license tiers?

Maryland issues Apprentice Plumber/Gas Fitter, Journey Plumber/Gas Fitter, Master Plumber/Gas Fitter, limited plumbing, natural-gas-fitter, and propane credentials. The standard path to a master credential runs through the apprentice and journey licenses. Baltimore County and WSSC issue their own plumbing credentials in their jurisdictions.

How long is the Maryland plumbing apprenticeship?

For the standard journey path, hold an apprentice license for at least four years, complete 7,500 supervised training hours, and complete approved 32-hour backflow-prevention-device-testing training before taking the journey examination.

How do I become a Maryland Master Plumber?

Hold a journey license for at least two years, complete 3,750 hours of supervised training as a journey plumber, and pass the PSI Master Plumber/Gas Fitter examination at 70%.

Does a Maryland master plumber license include gas fitting?

The standard credential is Master Plumber/Gas Fitter, and the statute defines a master plumber as authorized for plumbing and natural-gas services. Maryland also has separate natural-gas-fitter licenses for qualified non-plumbers and a separate propane certificate.

How often does the Maryland Master Plumber license renew?

The license renews for two years and is scheduled to expire on the first May 1 in an odd-numbered year. The current master renewal fee is $87.50; contracting licensees also submit the required insurance. The Board’s published CE requirement is for plumbing inspectors, not ordinary master-plumber renewal.

Primary Sources

Regulatory requirements on this page are drawn from the official board, statute, and exam-provider materials listed below.

Verified 2026-09-04 · Next scheduled review 2026-12-03

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Corrections and presentation updates

2026-09-30: Corrected examination detection when format details are unpublished and updated the summary layout and requirements score. Source-check dates are unchanged.
2026-09-08: Shared template updated to distinguish unspecified eligibility requirements, retain cost qualifications, and use consistent headings. Source-check dates are unchanged by presentation updates.
2026-09-21: Local-only guides now use a compliance-focused structure and terminology instead of implying a statewide license application. Source-check dates are unchanged by this presentation update.