- Massachusetts and PSI do not publish an aggregate MA-JP pass rate; passing is defined structurally, not statistically.
- Each part - Written and Practical - requires at least 70% independently; scores are never combined.
- Gas Piping, Equipment, and Appliances (21 questions) and Isometric Analysis (20 questions) carry the most weight and the most risk.
- Only the failed part must be retaken, at an $80 retest fee, inside a 12-month examination window.
Does Massachusetts Publish a Pass Rate?
Anyone searching for a single number that answers "what percentage of candidates pass the MA-JP exam" will come up empty. Neither the Massachusetts Board of State Examiners of Plumbers and Gas Fitters nor PSI Services LLC, the administering vendor, releases aggregate pass-rate statistics for the Journeyman Plumber License Examination. There is no annual report, no percentage breakdown by domain, and no publicly tracked cohort data.
That absence of a headline number doesn't mean there's nothing to analyze. The exam's own structure - its scoring rules, domain weighting, and retake mechanics - tells you exactly where risk concentrates and what "passing" actually requires. This article treats those structural facts as the data, because they are the only verifiable numbers that exist for this credential.
How Passing Is Actually Determined
The MA-JP exam is split into two closed-book, computer-based parts administered through PSI. Part I Written contains 80 questions with 160 minutes allotted, and Part II Practical contains 40 questions with 160 minutes allotted. Combined, the full exam line totals 120 questions across 320 minutes.
The critical detail - and the one most candidates misunderstand - is that the two parts are scored independently. Each part requires a minimum of 70% to pass on its own. Massachusetts does not average the two scores or allow a strong Written result to offset a weak Practical result, or vice versa. A candidate who scores well above 70% on Part I but just under 70% on Part II has not passed the exam overall, even though the combined average might look respectable.
This independent-scoring rule is the single biggest factor shaping how you should prepare. It rewards balanced competence across both parts rather than excellence in one and neglect in the other. For a full breakdown of the scoring thresholds themselves, see the MA-JP Passing Score 2026 guide.
Key Takeaway
Treat Part I and Part II as two separate exams with two separate 70% thresholds. Studying only for the larger Written part while ignoring the Practical section is a common way candidates fail despite feeling "ready."
Which Domains Carry the Most Risk
The MA-JP exam draws from 16 domains split across the two parts. Domains 1 through 12 belong to Part I Written; Domains 13 through 16 belong to Part II Practical. Because each domain has a fixed number of questions, you can see exactly where the exam concentrates its scoring weight - and therefore where a single knowledge gap does the most damage.
| Domain | Part | Question Count |
|---|---|---|
| 2. Gas Piping, Equipment, and Appliances | Written | 21 |
| 10. Drain, Waste, and Vent | Written | 13 |
| 3. Venting | Written | 12 |
| 1. General Regulations, Inspections, and Permits | Written | 9 |
| 8. Water Supply | Written | 6 |
| 13. Isometric Analysis | Practical | 20 |
| 16. Gas Venting | Practical | 8 |
| 15. Gas Piping | Practical | 7 |
| 14. General Trade Calculations | Practical | 5 |
Two domains stand out immediately. Gas Piping, Equipment, and Appliances is the largest section on the entire Written part at 21 of 80 questions - more than a quarter of Part I. On the Practical side, Isometric Analysis dominates with 20 of 40 questions, exactly half of that part. Weakness in either of these two domains alone can push a candidate below the 70% threshold for that part, regardless of how well the smaller domains are handled.
By contrast, domains like Traps and Cleanouts, Fixtures/Equipment/Clearances, Hangers and Supports, and Joints and Connections each carry only 2 questions. Spending equal study time on a 2-question domain and a 21-question domain is a poor use of preparation hours. A full walkthrough of every domain's scope and question style is available in the MA-JP Exam Domains 2026 guide, which pairs well with the difficulty analysis in How Hard Is the MA-JP Exam?.
Gas Piping, Equipment, and Appliances (Domain 2)
The single largest content area on Part I Written. Candidates should be fluent in sizing, appliance connections, and code references drawn from NFPA 54 and the Massachusetts Uniform State Plumbing Code.
- 21 of 80 Written questions - over a quarter of the part
- Directly tied to the 2012 NFPA 54 reference listed in the current handbook
- Overlaps conceptually with Domains 15 and 16 on the Practical part
Isometric Analysis (Domain 13)
The dominant section of Part II Practical, requiring candidates to read and interpret isometric drawings under timed conditions.
- 20 of 40 Practical questions - half the part
- Tests applied reading of piping layouts, not memorization
- Pairs with Domain 14 (General Trade Calculations) for sizing and load work
Retake Rules and the 12-Month Window
PSI's testing structure builds in a forgiving but time-limited retake path. Because Part I and Part II are scored separately, a candidate who fails only one part does not need to retake the part they already passed. Only the failed part must be scheduled again.
Each retest carries an $80 fee, identical to the original examination fee. There is no separate "combined retake" fee - you pay per part attempted. Application approval opens a 12-month examination window during which the candidate can sit for and, if necessary, retake either part. Once a part is passed, that score remains valid for one year, so it's important to finish the other part and complete licensure paperwork within that window rather than letting an approved score lapse.
Eligibility Factors That Influence Outcomes
Unlike some trade exams, MA-JP candidates arrive with a mandatory floor of hands-on experience, which shapes who sits for the test in the first place. The standard apprentice-route eligibility path (for apprenticeships beginning on or after September 1, 2008) requires a high-school diploma or equivalent, 6,800 hours of qualifying supervised work as a licensed plumbing apprentice, and 550 hours of approved plumbing and gas-fitting theory spread over at least four years. Work and education hours must satisfy the concurrent-training rules under 248 CMR 11.02.
That means every candidate walking into the PSI test center has already logged years of field time under a licensed plumber before ever seeing an exam question. This is a meaningful structural difference from certifications that allow candidates to test with little or no supervised experience - the eligibility bar itself filters for practical familiarity with gas piping, venting, and drainage systems long before exam day. For the full documentation and hour requirements, see MA-JP Requirements 2026.
Where candidates still struggle is translating years of hands-on repetition into the specific vocabulary and code citations the exam expects - particularly on smaller-weighted domains like Separators/Interceptors/Grease Traps or Hangers and Supports, which apprentices may encounter less frequently on the job than high-volume tasks like gas appliance hookups.
A Domain-Weighted Study Timeline
Rather than splitting study time evenly across 16 domains, allocate time in proportion to question count. The table above already shows the weight; the timeline below applies it.
Gas Piping, Venting, and Drain/Waste/Vent
- Master Domain 2 (Gas Piping, Equipment, and Appliances) - the largest Written domain at 21 questions
- Cover Domain 10 (Drain, Waste, and Vent) and Domain 3 (Venting), the next two heaviest Written sections
- Cross-reference the 2012 NFPA 54 and 2023 Massachusetts Uniform State Plumbing Code sections cited in the current handbook
Remaining Written Domains and Regulations
- Work through Domain 1 (General Regulations, Inspections, and Permits) and Domain 8 (Water Supply)
- Clear the smaller 2-3 question domains (Traps and Cleanouts, Fixtures, Water Heaters, Piping/Valves/Controls, Separators/Interceptors, Hangers, Joints) in batch review sessions
- Take a timed 80-question practice run to simulate the 160-minute Written limit
Isometric Analysis and Trade Calculations
- Spend the majority of practical prep on Domain 13 (Isometric Analysis) - 20 of 40 questions
- Layer in Domain 14 (General Trade Calculations) for sizing and load math that supports isometric reading
Gas Piping and Gas Venting on the Practical Side, Then Full Simulation
- Finish Domain 15 (Gas Piping) and Domain 16 (Gas Venting)
- Run a full 120-question, 320-minute simulation covering both parts back to back
- Confirm your nonprogrammable, nonprinting, silent, battery-operated calculator has no alphabetic keys before test day
This structure is expanded in more detail, including question-style breakdowns and pacing drills, in the MA-JP Study Guide 2026. If you want a condensed reference to carry through final review, the MA-JP Cheat Sheet 2026 consolidates the highest-weight facts from every domain onto one page.
The Real Cost of a Failed Attempt
Because there's no published pass rate to anchor expectations, it helps to think in terms of consequences rather than probabilities. Failing a part doesn't reset your entire application - you keep your Board approval and only owe an $80 retest fee for the part you failed - but it does cost time inside your 12-month window and delays the $52 initial journeyman license fee you'll eventually pay once both parts are passed.
Every dollar and week spent on retakes is avoidable friction. A full accounting of application, exam, retest, and licensing fees is broken down in MA-JP Certification Cost 2026, and it's worth reviewing before you schedule so a failed attempt doesn't catch your budget off guard.
Once licensed, remember that renewal is biennial by May 1 in even-numbered years for $52, with 12 approved continuing-education hours required per cycle (waived for a first license issued during the current renewal cycle). Passing the exam is the front-loaded effort; staying current afterward is comparatively light. You can practice full-length, domain-weighted simulations of both parts on our MA-JP practice test platform before committing to an official PSI date.
Key Takeaway
Since no official pass-rate percentage exists, use the domain question counts and the 70%-per-part rule as your real risk map. Concentrate the most hours on Gas Piping, Equipment, and Appliances and Isometric Analysis, since those two domains alone determine roughly a quarter of the Written score and half the Practical score.
FAQ
Massachusetts and PSI do not publish an official pass rate for the Journeyman Plumber License Examination. The only verified passing standard is that each part - Written and Practical - must independently score at least 70%.
No. Only the failed part needs to be retaken. A passing score on the other part remains valid, though it is only good for one year, so schedule the retake promptly within your 12-month examination window.
Gas Piping, Equipment, and Appliances is the largest Written domain at 21 of 80 questions, and Isometric Analysis is the largest Practical domain at 20 of 40 questions. Weakness in either can single-handedly drop a part below 70%.
The retest fee is $80, the same as the original examination fee, and it applies only to the part being retaken, not the entire exam.
Standard eligibility already requires 6,800 hours of supervised apprentice work and 550 hours of approved theory over at least four years, so most candidates arrive with substantial hands-on background. The main gap tends to be translating that experience into exam-specific code citations and isometric reading skills.