This is the condensed version - the one page you skim the night before your PSI appointment or keep open in a second tab while you finish your last practice block. Every number here traces back to the Maryland State Board of Plumbing's own fee schedule, COMAR, and the PSI candidate bulletin, not to some other credential that happens to share the "MD-JP" letters. If you want the long-form version of any section, the linked guides below go deeper.
- Base exam is 100 questions in 240 minutes; passing score is 70%, per COMAR 09.20.02.03.
- PSI may tack on 5-10 unscored questions with extra time - don't panic if the count feels off.
- Gas Appliances and Piping is the single largest domain, followed by Drain, Waste, and Vent Systems and Backflow Prevention.
- Open book means tabs and highlighting only - handwritten notes and outside study guides are disqualifying.
Exam Format at a Glance
The official title is the Journey Plumber/Gas Fitter examination; "journeyman plumber" is simply the common search term, and MD-JP is this site's shorthand for it. The Maryland Department of Labor sets the licensing rules, the Maryland State Board of Plumbing enforces them, and PSI Services LLC delivers the actual computer-based test at its testing centers.
- Question count: 100 scored, multiple-choice questions
- Time allowed: 240 minutes for the base exam
- Experimental questions: PSI may insert 5 to 10 unscored pilot questions, with additional time added outside the base 240-minute allowance
- Delivery: computer-based, at a PSI test center
- Passing score: 70%
For a deeper breakdown of what "hard" actually means for this exam - content difficulty versus time pressure versus open-book logistics - see How Hard Is the MD-JP Exam? Complete Difficulty Guide 2026.
Fees, Eligibility, and Registration Mechanics
Under the Board's fee schedule effective July 1, 2025, the numbers are straightforward and worth memorizing so nothing surprises you at registration or renewal time:
| Item | Cost / Requirement |
|---|---|
| PSI examination fee | $65 |
| Initial Journey license | $43.50 |
| License renewal (biennial) | $43.50 |
| Routine CE for ordinary Journey license | Not required |
A full cost breakdown, including how these fees compare to the time investment of your apprenticeship, is covered in MD-JP Certification Cost 2026: Complete Pricing Breakdown.
Ordinary eligibility to sit for the exam requires:
- Four years as a licensed apprentice
- 7,500 hours of work under a licensed Master plumber
- A current, approved 32-hour backflow-prevention device testing course
- Up to 1,500 hours from approved trade school may count toward the total experience requirement
Applications must be submitted online only, a rule PSI's bulletin has enforced since March 31, 2025 - no paper applications. For the complete eligibility walkthrough, including how school hours interact with apprentice hours, see MD-JP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Key Takeaway
WSSC and Baltimore County run their own separate licensing arrangements outside the standard state process - if you work in those jurisdictions, confirm which credential you actually need before you register with PSI.
The Nine Domains, Ranked by Weight
The exam blueprint spreads 100 questions across nine domains, and they are not weighted evenly. Knowing which domains carry the most questions should directly shape how you allocate study hours.
Domain 8: Gas Appliances and Piping
This is the largest domain on the exam. Expect questions on gas piping sizing, appliance venting, shutoff placement, and code-driven installation clearances. Because "Gas Fitter" is literally in the exam's official name, underestimating this domain is the single most common preventable mistake.
- Gas pipe sizing and material selection
- Appliance connection and venting requirements
- Shutoff valve placement and access
Domain 7: Drain, Waste, and Vent Systems
The second-largest domain. DWV questions test slope, sizing, cleanout placement, and venting configurations under real installation scenarios rather than pure definitions.
- Pipe sizing based on fixture units
- Vent system configurations
- Cleanout spacing and access requirements
Domain 6: Backflow Prevention
The third-largest domain, and it overlaps directly with the 32-hour backflow-prevention course required for eligibility. Study this domain and your eligibility coursework together rather than as separate tracks.
- Device types and where each is required
- Cross-connection control principles
- Testing and certification basics
The remaining six domains - Plumbing Fundamentals and Safety, Materials, Uses, and Specifications, Traps, Interceptors, and Backwater Valves, Plumbing Fixtures, Fixture Fittings, and Plumbing Appliances, Water Supply Systems, and Plumbing Mathematics - round out the blueprint. For the full official allocation, question-style breakdown, and study sequencing for all nine areas, read MD-JP Exam Domains 2026: Complete Guide to All 9 Content Areas.
Open-Book References and Tools
This exam is open book, but "open book" has strict limits candidates frequently misjudge:
- Allowed: approved reference books with permanent tabs and highlighting
- Not allowed: handwritten notes, loose or added papers, outside study guides
- Calculator: must be silent, nonprinting, nonprogrammable, and without an alphabetic keyboard
The public PSI bulletin (dated September 1, 2024) references the 2018 IPC and 2018 IFGC, but June 2026 Board minutes discuss a 2024-code examination update. That means the assigned reference editions may be in transition - verify the exact code editions with PSI before you buy or tab any books. Don't assume last year's reference list still applies without checking.
Key Takeaway
Tab your approved code books by topic (gas piping, DWV sizing, backflow devices) before test day - you will not have time to hunt through an untabbed code book question by question inside 240 minutes.
Scoring, Retesting, and Licensing Deadlines
The passing threshold is 70%, confirmed both by the PSI candidate bulletin and by COMAR 09.20.02.03. For exact scoring mechanics and how the Board reports results, see MD-JP Passing Score 2026: Exactly What You Need to Pass.
The Board's June 18, 2026 minutes reported a Journey Plumber/Gas Fitter pass rate of 43% for that May 2026 sitting - 27 of 63 candidates passed. That's a single monthly cohort result, not an annual figure and not a first-attempt-only statistic, so don't extrapolate it beyond what it actually measures. A closer look at what this data does and doesn't tell you is in MD-JP Pass Rate 2026: What the Data Shows.
- Retest policy: once per 30 days if you don't pass
- License application window: apply within one year of your passing exam date
- Renewal cycle: biennial, no routine CE required for an ordinary Journey license (plumbing inspector CE is a separate track)
Final-Week Review Plan
If you've already done the bulk of your studying, the last stretch should be about reinforcement and logistics, not new material. Sequence your last week around the domain weighting rather than reviewing everything equally.
Gas Appliances and Piping + Drain, Waste, and Vent Systems
- Redo sizing calculations by hand
- Confirm tabbed references cover venting and cleanout rules
Backflow Prevention + Water Supply Systems
- Cross-check device requirements against your 32-hour course notes
- Review cross-connection scenarios
Remaining Domains + Full Timed Run
- Fundamentals, Materials, Traps/Interceptors, Fixtures, and Plumbing Mathematics
- One full 100-question timed practice session under 240 minutes
Logistics and Light Review
- Confirm calculator meets the silent/nonprogrammable rule
- Verify reference book editions with PSI
- Light review only - no new topics
For a longer-range plan that starts weeks or months out, see MD-JP Study Guide 2026: How to Pass on Your First Attempt. And if you're still deciding whether the license is worth pursuing given the time and fee investment, Is the MD-JP Certification Worth It? Complete ROI Analysis 2026 and MD-JP Salary Guide 2026: Complete Earnings Analysis lay out the practical case.
Once you're licensed, plenty of Maryland employers - contractors handling both plumbing and gas work, given the exam's combined scope - specifically look for candidates who hold this credential; a look at typical postings is in MD-JP Jobs. If you're still building experience hours, structured coursework can help you track progress toward the 7,500-hour requirement - see MD-JP Training. And if you landed here without knowing what the credential even covers, start with What Is MD-JP? or MD-JP Certification before diving into domain-level prep.
Whatever stage you're at, running realistic timed questions against the actual domain weighting matters more than passive review. You can start practicing directly on the main MD-JP practice test platform to see where your weak domains actually are before test day, rather than guessing from memory.
FAQ
The base exam is 100 scored multiple-choice questions with 240 minutes allowed. PSI may add 5 to 10 unscored experimental questions, with extra time provided outside that base allowance.
70%, as confirmed by the PSI candidate bulletin and COMAR 09.20.02.03.
Gas Appliances and Piping carries the most questions, followed by Drain, Waste, and Vent Systems and Backflow Prevention. Study these three first and most thoroughly.
No. Only approved reference books with permanent tabs and highlighting are allowed. Handwritten notes, loose papers, and outside study guides are prohibited.
You may retest once every 30 days. If you do pass, you must apply for the license within one year of your passing exam date to avoid requalifying.