- What "Pass Rate" Actually Means for MD-MP
- The May 2026 Numbers: 8 of 20 Candidates
- Why a Single-Month Snapshot Isn't the Whole Story
- How the Exam Format Filters Candidates
- Domain Weighting and Where Points Are Won or Lost
- Eligibility Filters That Shape Who Sits the Exam
- Retake Mechanics and the Cost of Failing
- A Study Approach Built Around the Real Weighting
- Frequently Asked Questions
- The Maryland Board reported 8 passes out of 20 candidates for May 2026 - a 40% single-month rate, not an overall or first-attempt figure.
- Passing requires 70% correct on 100 scored questions in 240 minutes, with 5-10 unscored experimental items mixed in.
- Gas Appliances and Piping (Domain 9) carries 40 of 100 questions - by far the heaviest single domain.
- Retesting is capped at once every 30 days, so a failed attempt costs at least a month plus another $65 fee.
What "Pass Rate" Actually Means for MD-MP
Anyone researching the Maryland Master Plumber License Exam (MD-MP) eventually asks the same question: what percentage of people actually pass? It's a fair question, but the honest answer is more nuanced than a single number. The Maryland State Board of Plumbing, working with PSI Examination Services as the testing vendor, doesn't publish a rolling annual pass rate the way some national certification bodies do. What exists publicly is a snapshot - a specific month's results for the combined Master Plumber/Gas Fitter examination.
That distinction matters because a single-month figure can swing based on who happened to sit for the exam that cycle, how many were retaking after a prior fail, and how many were first-timers who under-prepared for the heaviest domain. Before you build a study plan around a percentage, it helps to understand exactly what that percentage reflects - and what it doesn't.
The May 2026 Numbers: 8 of 20 Candidates
The most concrete data point available is from the Maryland Board's reporting for May 2026: eight passes among 20 Master Plumber/Gas Fitter candidates, which works out to a 40% single-month pass rate. This is not a first-attempt rate, and it is not a cumulative or annual rate - it's a snapshot of one testing cycle's outcomes for the combined exam.
Still, a figure like this is useful. It confirms that failing is common enough that preparation matters - this isn't an exam where passive familiarity with plumbing work is enough to clear a 70% cut score across 100 scored questions. If you want the full breakdown of what that cut score means in practice, the MD-MP Passing Score 2026 guide walks through exactly how scored versus unscored questions factor into your result.
Why a Single-Month Snapshot Isn't the Whole Story
A 40% pass rate in one reporting month doesn't mean your personal chance of passing is 40%. Pass rates for licensing exams are influenced by several factors that vary candidate to candidate:
- Prior exposure to the material. Candidates who have already spent years doing gas piping and appliance connections under supervision walk in with a structural advantage over someone whose journeyman work skewed toward fixtures and DWV systems.
- Familiarity with the open-book references. The exam allows candidates to bring approved code references, including the 2018 IPC and 2018 IFGC per the board-linked bulletin dated September 1, 2024. Candidates who haven't practiced navigating those books under time pressure lose minutes they can't get back.
- Retake candidates mixed into the pool. Because retesting is allowed no more often than every 30 days, some portion of any given month's candidates are repeat test-takers, which can pull a monthly figure in either direction.
For a deeper look at how these variables combine to make the exam feel harder or easier than a raw percentage suggests, see How Hard Is the MD-MP Exam? Complete Difficulty Guide 2026.
How the Exam Format Filters Candidates
The MD-MP exam is computer-based, multiple choice, with 100 scored questions delivered in 240 minutes. PSI may insert five to 10 additional unscored experimental questions, and the extra time those take does not count against your four-hour allowance - but you won't know which questions are experimental, so every item has to be treated as if it counts.
The passing threshold is 70%, meaning you need roughly 70 of the 100 scored items correct. That's a straightforward target on paper, but the exam is open-book with restrictions: permanent tabs, highlighting, and underlining in your approved code books are allowed, while handwritten notes, loose papers, and outside study guides are prohibited. This format rewards candidates who've organized their reference material in advance and penalizes those who plan to "look things up" cold during the test.
Key Takeaway
Tab and highlight your 2018 IPC and 2018 IFGC well before test day. You cannot bring handwritten notes or supplemental guides - your only speed advantage is a book you already know how to navigate.
Because the June 2026 board minutes discuss 2024-code examination revisions, it's worth confirming the exact reference edition tied to your booked exam date before you buy or tab any books. Reference editions can shift between testing cycles, and studying the wrong code year wastes preparation time.
Domain Weighting and Where Points Are Won or Lost
The 100 scored questions are not distributed evenly across the exam's content areas. Here is the official allocation:
| Domain | Questions |
|---|---|
| 1. Plumbing Fundamentals and Safety | 5 |
| 2. Materials, Uses, and Specifications | 6 |
| 3. Traps, Interceptors, and Backwater Valves | 4 |
| 4. Plumbing Fixtures, Fixture Fittings, and Plumbing Appliances | 4 |
| 5. Water Supply Systems | 8 |
| 6. Backflow Prevention | 10 |
| 7. Drain, Waste, and Vent Systems | 13 |
| 8. Special Topics | 3 |
| 9. Gas Appliances and Piping | 40 |
| 10. Plumbing Mathematics | 7 |
This lopsided weighting explains a lot about why a pass rate sits where it does. A candidate can be excellent at Drain, Waste, and Vent Systems (13 questions) and Backflow Prevention (10 questions) and still fail if gas piping sizing, appliance venting, and fuel-gas code requirements aren't second nature. For a full walkthrough of what each domain actually tests, the MD-MP Exam Domains 2026 guide breaks down all ten content areas in detail, and pairing that with a structured plan from the MD-MP Study Guide 2026 is the most direct way to close domain-specific gaps before test day.
Domain 9: Gas Appliances and Piping
With 40 of 100 scored questions, this domain alone can determine your pass/fail outcome. Candidates should be fluent in:
- Gas pipe sizing methods and material selection for different fuel-gas applications
- Appliance venting requirements and clearance-to-combustible rules
- Shutoff valve placement, testing, and code-required safety devices
- Cross-references between the 2018 IFGC and related plumbing code sections
Eligibility Filters That Shape Who Sits the Exam
Pass rates don't exist in a vacuum - they're partly a function of who is even allowed to test. Maryland's standard eligibility path requires a journey license held for at least two years and 3,750 supervised training hours under a licensed master plumber. PSI also requires a current, approved 32-hour backflow prevention device testing certificate, along with work records and identification, before you're cleared to sit for the exam.
These prerequisites mean the candidate pool isn't a random cross-section of plumbers - it's experienced journey-level tradespeople who've already logged years of field hours. That the pass rate still hovers where it does, per the reported May 2026 figures, tells you the exam is a genuine knowledge test, not a rubber stamp on experience. If you're still working through eligibility, the MD-MP Requirements 2026 guide covers the full checklist, and applications have been online-only since March 31, 2025, so plan your paperwork accordingly.
Retake Mechanics and the Cost of Failing
If you don't clear 70%, Maryland's rules mean the setback has both a time cost and a dollar cost. Retesting is allowed no more often than every 30 days, and each attempt carries its own $65 exam fee. That 30-day floor is exactly why a monthly pass rate like the May 2026 figure includes some mix of first-timers and retake candidates - the timing rules push repeat attempts into the very next available cycle rather than spreading them out.
Once you do pass, the clock starts again in a different way: you must apply for the license within one year of passing, and the license itself runs two years from issuance. Renewal for the general plumbing license carries no continuing education requirement, though the fee schedule effective July 1, 2025 sets both the initial master license and each renewal at $87.50. For a complete look at every fee across the process - exam, license, and renewal - see the MD-MP Certification Cost 2026 breakdown.
Key Takeaway
A failed attempt costs at least $65 and a minimum 30-day wait. Budgeting time for a possible retake - rather than assuming a single pass on the first try - is the more realistic way to plan your study calendar.
A Study Approach Built Around the Real Weighting
Generic study advice - spaced repetition, timed practice blocks, active recall - works for almost any exam, but it only pays off when it's pointed at the right material. For MD-MP specifically, that means allocating study time roughly in proportion to the question count, not evenly across all ten domains.
Gas Appliances and Piping (Domain 9)
- Work through gas pipe sizing tables and fuel-gas code sections repeatedly since this domain alone is 40% of the exam
- Tab your 2018 IFGC now so navigation is automatic by test day
Drain, Waste, and Vent Systems and Backflow Prevention
- Combined, these two domains account for 23 of 100 questions
- Practice cross-referencing venting diagrams against code text under time pressure
Water Supply Systems, Plumbing Mathematics, and remaining domains
- Cover Materials, Fundamentals, Fixtures, Traps/Interceptors, and Special Topics in lighter passes given their smaller question counts
- Run full-length timed practice sets to simulate the 240-minute window
Running full-length, timed practice questions modeled on the real domain distribution - rather than generic plumbing trivia - is the single best way to rehearse the actual test experience. That's the exact gap tools on our practice test platform are built to close, since drilling against a domain-weighted question bank mirrors the real exam far better than studying code books alone.
Frequently Asked Questions
The Maryland Board reported eight passes among 20 Master Plumber/Gas Fitter candidates for May 2026 - a 40% single-month rate. This figure is not a first-attempt rate or an overall historical rate, just one month's reported outcome.
You need 70% correct out of 100 scored questions. PSI may add five to 10 unscored experimental questions that don't count toward your score, but you won't know which ones those are during the test.
Gas Appliances and Piping carries 40 of the 100 scored questions, nearly half the exam. Weak preparation in this single domain is the most common reason otherwise capable candidates fall short of the 70% cut score.
Maryland allows retesting no more often than every 30 days, and each attempt requires a new $65 exam fee. Plan your study calendar assuming a possible retake rather than a guaranteed first-attempt pass.
No. You must apply for the license within one year of passing, and the initial master license carries an $87.50 fee under the schedule effective July 1, 2025. Insured-to-contract status also requires separate liability coverage before you can operate as a contractor.
Understanding a reported pass rate is useful context, but it's not a substitute for domain-by-domain preparation. If you want to see how this exam compares against other paths in terms of career payoff, the Is the MD-MP Certification Worth It? Complete ROI Analysis 2026 article and the MD-MP Salary Guide 2026 both dig into what the license means once you're past the exam itself. And when you're ready to test your readiness against realistic, domain-weighted questions, start practicing here before you lock in an exam date.