Maryland licenses its top plumbing tier as the Master Plumber/Gas Fitter — a combined plumbing and gas credential issued by the State Board of Plumbing in the Maryland Department of Labor. The Master examination is administered by PSI Services LLC as an open-book, computer-administered sitting of 100 questions in 240 minutes, passed at a minimum passing score of 70 percent, and examined on the 2018 International Plumbing Code and the 2018 International Fuel Gas Code. The PassProfessor Maryland Master Plumber/Gas Fitter program prepares experienced journey licensees for that sitting and for the eligibility, backflow, and regulatory depth that separates the master tier from the journey tier.
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What this credential is — and what it is not
Maryland does not offer a plumbing-only master examination. The master credential is the Master Plumber/Gas Fitter: one license joining plumbing and gas fitting in a single examined tier, and the combined examination is what this program prepares candidates for. The separate Master Natural Gas Fitter examination — 40 questions drawn from the fuel gas code only — is a different credential for a different scope of practice, and appears here only as ladder context so candidates do not prepare for the wrong sitting.
The licensing authority is the State Board of Plumbing, in the Division of Occupational and Professional Licensing of the Maryland Department of Labor, acting under Title 12 of the Business Occupations and Professions Article and Title 09, Subtitle 20 of the Code of Maryland Regulations; the State Plumbing Code sits at COMAR 09.20.01. PassProfessor is independent and is not affiliated with the State Board of Plumbing, the Maryland Department of Labor, or PSI.
The honest headline: the Master sitting is the Journey sitting
Candidates deserve this fact stated plainly, because it shapes honest preparation. The Master Plumber/Gas Fitter examination uses the same sitting structure as the Journey examination: 100 questions, 240 minutes, open book, computer-administered through PSI, with the same published minimum passing score of 70 percent and the same examination fee of $65. There is no longer master paper and no additional master session to discover later.
What changes at the master tier is who may sit, what the license authorizes, and how the questions distribute. Eligibility narrows sharply: documented journey-level experience under a licensed master, plus a current approved course in backflow prevention device testing already completed. The outline shifts weight toward gas work — 40 of the 100 questions — and toward backflow prevention, water supply, and drainage systems at a level of regulatory judgement the journey sitting samples more lightly. A candidate who prepares as though the journey paper had simply returned will misjudge the sitting: the form is familiar; the centre of gravity is not.
The examination at a glance
| Item | Verified position |
|---|---|
| Credential | Maryland Master Plumber/Gas Fitter — the combined plumbing and gas master credential; there is no plumbing-only Master examination in Maryland |
| Regulator | State Board of Plumbing, Maryland Department of Labor, Division of Occupational and Professional Licensing — Business Occupations and Professions Article, Title 12; COMAR Title 09, Subtitle 20; State Plumbing Code at COMAR 09.20.01 |
| Administrator | PSI Services LLC — PSI provides all testing for the Board; prior PSI approval is required before scheduling; PSI Qualification Information Bulletin 7404, dated August 10, 2026 |
| Structure | 100 questions / 240 minutes / OPEN BOOK / computer-administered — the same sitting structure as the Journey Plumber/Gas Fitter examination |
| Passing standard | Minimum Passing Score 70 percent, as published in the PSI bulletin for the Maryland plumbing and gas examinations |
| Tested editions | 2018 International Plumbing Code and 2018 International Fuel Gas Code |
| Adopted edition | 2021 International Plumbing Code under COMAR 09.20.01 as amended effective November 24, 2025 — adopted is not tested; see the edition section below |
| Examination fee | $65, paid for one examination, as printed in the PSI bulletin for Master Plumber/Gas Fitter |
| Practical component | None published for this credential — the examination as published is a written, computer-administered examination only |
| Administrator note | PassProfessor is independent and is not affiliated with the State Board of Plumbing, the Maryland Department of Labor, or PSI |
Tested is not adopted: the edition question every Maryland candidate must get right
Maryland currently examines on one code edition and installs under another, and confusing the two is the most expensive preparation error available in this state. The PSI bulletin lists the 2018 International Plumbing Code and the 2018 International Fuel Gas Code as the reference materials for both the Master and the Journey examinations. Those are the editions the sitting tests.
The adopted layer moved. COMAR 09.20.01.01, as amended effective November 24, 2025, adopts the most recent plumbing code dynamically, through the code incorporated in the Maryland building regulations — the 2021 International Plumbing Code — and the former Maryland modification regulations were repealed on the same date. Work in Maryland is now governed by the 2021 layer, while candidates are still tested on 2018 until a new Board and PSI test takes effect; no primary source retrieved names the 2021 editions as examination references, and a 2024 Board discussion of a future newer-code test has not changed the current bulletin’s list. Preparation therefore means fluency in the 2018 books, handled carefully enough that a provision remembered from 2021 field practice does not silently replace the 2018 answer.
Where the 100 questions sit
The published master outline sums to 100 questions, and its shape tells the candidate where the tier lives. Gas Appliances and Piping carries 40 questions — two-fifths of the entire paper. Drain, Waste, and Vent Systems carries 13; Backflow Prevention 10; Water Supply Systems 8; Plumbing Mathematics 7; Materials, Uses, and Specifications 6; Plumbing Fundamentals and Safety 5; Traps, Interceptors, and Backwater Valves 4; and Plumbing Fixtures, Fixture Fittings, and Plumbing Appliances 4. A final block, Special Topics, carries 3 questions; the sources do not define its content, and this program does not invent a topic list for it.
Two comparisons with the journey outline matter: the journey paper gives 8 questions to Fundamentals and Safety where the master paper gives 5, and it has no Special Topics block at all. The rest of the shift is emphasis rather than architecture — the master candidate is examined as someone responsible for gas systems, cross-connection control, and complete drainage and supply systems, not merely as someone who installs them under another licensee’s direction. The bulletin also provides that between 1 and 10 experimental items, generally approximately 10 percent, may be administered unscored, and under the current wording those items count against examination time. The clock runs on everything placed in front of the candidate.
The remaining listed references — Mathematics for Plumbers and Pipefitters, 8th Edition (2013), any standard backflow text, and 29 CFR Part 1926 — complete an open-book sitting that rewards a prepared library. Open book does not mean unprepared: in 240 minutes, a candidate who must search for every answer runs out of time long before running out of questions.
Who may sit: eligibility is the real master gate
The Maryland-experience route requires certification of at least two years — stated as 3,750 working hours — of practical experience as a licensed Maryland Journey Plumber under the direction and control of a licensed Maryland Master Plumber, plus a non-expired, approved 32-hour course in Backflow Prevention Device Testing. That course is not part of the examination; it is an eligibility condition that must already be satisfied, and a candidate who discovers it late delays the sitting, not the study plan.
The bulletin also prints routes for experience gained outside Maryland. In substance, the non-Maryland track calls for 3,750 hours in the trade after journey licensure, spanning at least two years; an original certification of at least four years and 7,500 hours under a licensed master before journey licensure; verification letters establishing 11,250 total hours and that the supervising master’s license was itself obtained by passing a written competency examination; and the same 32-hour backflow course. A parallel track is printed for jurisdictions that do not license journey plumbers. On any out-of-state route, the file — not the examination room — is where the application succeeds or fails, so documentation should be checked against the bulletin’s exact wording well before a sitting date is planned.
For ladder context, the journey tier rests on an apprenticeship foundation of at least four years and 7,500 hours together with the same backflow course requirement. One caution for accuracy: Maryland law changed the journey route in 2025, and approved apprenticeship-program completers may qualify at the journey level without the journey examination under that provision. Master applications should therefore show the documented experience the bulletin requires, in the form it requires, rather than assume every journey record passed through an identical examined route.
A passing score also carries a clock: an applicant has one year from the date the examination was taken to apply for the license.
Fees, stated only where the sources state them
The PSI examination fee for the Master Plumber/Gas Fitter examination is $65 — printed in the bulletin for this examination specifically, not borrowed from the journey examination, whose fee is also $65. It covers one examination, is not refundable or transferable, and remains valid for one year. No Board license-issuance dollar figure is printed here, because no current Board fee schedule was among the verified sources for this program and figures in other layers of Maryland material belong to different charges; confirm current Board fees with the Board directly.
There is no continuing education requirement to maintain a Maryland master license. The eight-hours-per-year figure in Maryland material applies to plumbing inspector cards, a different credential.
After a sitting: scores, rescheduling, and what happens next
The score is given immediately on completion. A candidate who does not pass is given 30 minutes at the end of the examination to review missed items at no charge, together with re-application instructions. This page states no minimum waiting period and no attempt limit for a retake, because the current bulletin states neither: the retake-timing sentence in an earlier bulletin was dropped from the current one, and printing the old interval as current would mislead candidates when they most need accuracy. The current position is confirmed with PSI and the Board at re-application.
Scheduling discipline is firmer: cancel or reschedule without forfeiting the fee only when notice is received 48 hours before the scheduled date and time, through the PSI website or by speaking directly with a PSI representative — voicemail and email are not acceptable. Separately, on the licensing side, a license expired for more than four years requires retesting.
What the PassProfessor program will cover
The PassProfessor Maryland Master Plumber/Gas Fitter program is in the works as part of our expanding catalog of trade licensing preparation, and enrollment is not yet open. Its design follows the credential itself. The largest share of preparation follows the largest share of the paper: gas appliances and piping from the 2018 fuel gas code at master depth — sizing, venting, appliance installation, and the judgement calls that arise when a complete gas system is one licensee’s responsibility. Drainage, waste, and vent systems, water supply, and backflow prevention form the second core; backflow preparation aligns with the body of knowledge the separate 32-hour eligibility course certifies, while noting plainly that program study does not substitute for that required course. Mathematics, materials, fixtures, traps and interceptors, and fundamentals and safety complete the outline.
Two disciplines run through every section: edition discipline — material keyed to the tested 2018 editions, with the adopted 2021 layer flagged wherever field habits pull toward the newer book — and open-book method, the locating, confirming, and moving-on habits that turn 240 minutes into an advantage rather than a search exercise. Every item is written from scratch against primary sources. The companion guide, the Maryland Master Plumber/Gas Fitter Exam Guide, works through the outline, the eligibility file, and a full study method in greater depth.
Completing this program will confer no license and no eligibility. The Board alone licenses, PSI alone administers the sitting under the Board’s authority, and candidates register and schedule through the official channels.
Tell me when enrollment opens. Leave an email address and PassProfessor will write to you when the Maryland Master Plumber/Gas Fitter program is ready — and only about this program. No date is promised, because the program will open when it meets the standard described above, not before.
Frequently asked questions
Is there a plumbing-only Master examination in Maryland?
No. The master credential is the combined Master Plumber/Gas Fitter. The separate Master Natural Gas Fitter examination, at 40 questions on the fuel gas code only, is a different credential.
How is the Master examination different from the Journey examination?
In sitting structure, it is not different: both are 100 questions in 240 minutes, open book, computer-administered through PSI, passed at 70 percent, for a $65 examination fee. The differences are eligibility, the license the result supports, and the content distribution — including 40 gas questions and a small Special Topics block on the master outline.
Which code editions does the Master examination test?
The 2018 International Plumbing Code and the 2018 International Fuel Gas Code, as listed in the current PSI bulletin.
Maryland adopted a newer plumbing code. Why prepare from the 2018 books?
Because tested is not adopted. COMAR 09.20.01 as amended effective November 24, 2025 adopts the 2021 International Plumbing Code for installations, while the current examination references remain the 2018 editions until a new test takes effect.
What experience does a Maryland journey licensee need for the Master examination?
Certification of at least two years, stated as 3,750 working hours, of practical experience as a licensed Maryland Journey Plumber under the direction and control of a licensed Maryland Master Plumber, plus a non-expired approved 32-hour course in Backflow Prevention Device Testing.
What does the examination cost?
The PSI examination fee is $65 for one examination. It is nonrefundable, nontransferable, and valid for one year.
Is there a hands-on practical on the Master examination?
No practical, drawing, or takeoff component is published for this credential. The examination as published is a written, computer-administered examination only.
How long is a passing score good for?
An applicant has one year from the date the examination was taken to apply for the license.
Does Maryland require continuing education for master plumbers?
No continuing education requirement applies to maintaining this license. The eight-hours-per-year figure in Maryland material applies to plumbing inspector cards, not to this credential.
If I do not pass, how soon can I sit again?
The current bulletin states no minimum interval and no attempt cap; a candidate who does not pass receives re-application instructions at the sitting and should confirm the current position with PSI and the Board. Older material stating a fixed interval is not current.
Is PassProfessor affiliated with the Board or PSI?
No. PassProfessor is an independent preparation provider, not affiliated with the State Board of Plumbing, the Maryland Department of Labor, or PSI Services LLC.
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.