- Written exam is 70 scored questions in 185 minutes; you need 53 correct (75%) to pass.
- Practical exam is 100 points in 120 minutes; 75 points passes.
- Total cost for application plus both first attempts is $212.76 ($68.88 written, $68.88 practical, $75 application/certificate fee).
- Drainage Waste and Vents is the largest of the nine written domains - prioritize it.
NM-JP At a Glance
The New Mexico Journeyman Plumber (JP) Certificate of Competence Exam - referred to on this site by its identifier, NM-JP - is administered through the Construction Industries Division (CID) under the Regulation and Licensing Department (RLD), with PSI Services LLC handling testing and application logistics. This cheat sheet compresses the numbers, deadlines, and domain weighting you need into one scannable reference. It's meant to sit alongside deeper resources like the NM-JP Study Guide 2026 and the NM-JP Requirements 2026 breakdown, not replace them.
If you're still confirming what this credential actually is before diving into logistics, start with What Is NM-JP? or NM-JP Meaning. Everyone else, keep reading - this page is built for quick lookups during final review.
Fees, Scores, and Timing
Get these numbers memorized cold. They show up in eligibility planning, scheduling decisions, and budget conversations with employers who may reimburse testing costs.
| Item | Detail |
|---|---|
| Written exam fee | $68.88 |
| Practical exam fee | $68.88 |
| Combined written + practical | $137.76 |
| Application/certificate fee | $75 per classification |
| Total for application + both first attempts | $212.76 |
| Written exam length | 70 base questions, 185 minutes, computer-based |
| Written passing score | 75% (53 of 70 points) |
| Practical exam length | 120 minutes, 100 available points |
| Practical passing score | 75 points |
Note that the written exam can include up to ten unscored experimental questions, with additional time allotted so they don't eat into your 185 minutes for the 70 scored items. You won't know which questions are experimental, so treat every question as if it counts. For a full cost breakdown including how the numbers change if you need retakes, see NM-JP Certification Cost 2026. For a plain explanation of exactly what 53/70 and 75/100 mean in practice, check NM-JP Passing Score 2026.
Key Takeaway
Budget $212.76 minimum for application plus one attempt at each exam. No more than two attempts at the same exam are allowed within a 30-day window, so plan your study timeline instead of relying on a quick re-test.
The Nine Written Domains
The written component draws its 70 scored questions from nine domains. Knowing which domains carry the most weight tells you where to spend your limited review hours. Drainage Waste and Vents is the largest domain on the exam, so it deserves the largest share of your study calendar.
Domain 1: Drainage Waste and Vents
The heaviest-weighted domain. Expect questions on trap arms, vent sizing logic, cleanout placement, and drainage fixture unit loading.
- Know minimum and maximum trap arm lengths by pipe size
- Understand wet venting, common venting, and island venting logic
Domain 2: Water Supply Systems
Covers supply pipe sizing, water distribution, and pressure considerations.
- Understand fixture supply demand and pipe sizing tables
Domain 3: Backflow Prevention
Covers cross-connection control and device selection by hazard level.
- Match backflow preventer types to application (air gap, RPZ, vacuum breaker)
Domain 4: Storm Drainage Systems
Roof drainage, secondary drains, and sizing by rainfall/area calculations.
- Practice roof drain and leader sizing problems
Domain 5: Plumbing Fixtures, Including Water Heaters, Including Accessibility
Fixture installation clearances, water heater relief valves and venting, and ADA-style accessibility clearances.
- Memorize T&P relief valve requirements and discharge piping rules
Domain 6: General Knowledge and General Regulations
Administrative rules, code jurisdiction, and general plumbing definitions.
- Review permit and inspection concepts referenced in the applicable code edition
Domain 7: Interceptors and Traps
Grease interceptors, sand/oil separators, and individual fixture trap requirements.
- Know sizing rules and prohibited double-trapping scenarios
Domain 8: Isometric Analysis
Reading and interpreting isometric drawings for DWV and supply systems.
- Practice tracing pipe runs and identifying fitting types on isometric sketches
Domain 9: Septic and Sewer
Building sewer sizing, septic system basics, and connection requirements.
- Know minimum slope and cover requirements for building sewers
For a deeper walkthrough of each domain with sample question styles, read the full NM-JP Exam Domains 2026: Complete Guide to All 9 Content Areas. And if you're wondering how these domains combine into overall difficulty, How Hard Is the NM-JP Exam? Complete Difficulty Guide 2026 walks through that in detail.
Practical Exam Essentials
The practical exam is a separate 120-minute, hands-on assessment worth 100 points, requiring 75 to pass. It's not a written add-on - it's a physical demonstration of trade skill under time pressure.
- Copper/PEX piping: Clean, accurate joints matter as much as speed. Practice both soldering technique and PEX crimp/expansion methods.
- Tub and washer-box assemblies: Know standard rough-in dimensions and proper support/bracing.
- Fitting and tool identification: Be able to name fittings and tools instantly - no hesitation time built in.
- Island vent assembly: Review the loop vent logic tested in Domain 1 concepts, then apply it physically.
- Drainage minimum-rise setup: Practice calculating and physically achieving minimum slope over a given run.
Because the practical exam mirrors real fieldwork, employers who hire journeyman plumbers value this credential as proof of hands-on competence, not just test-taking ability. If you're mapping out how this credential translates into job opportunities, see NM-JP Jobs and NM-JP Salary Guide 2026.
Open-Book References and What's Allowed
Both the written and practical components are open book - a major advantage if you use it correctly. But "open book" does not mean "open anything."
Key Takeaway
Permanent tabs and highlighting in approved references are allowed. A silent, nonprinting, nonprogrammable calculator is allowed. Handwritten notes and loose added papers are prohibited - don't risk disqualification over a sticky note.
Two commonly misunderstood items: the written mathematics textbook and the liquid-waste regulations are source-only materials. They inform what's tested, but they are not permitted physical references inside the exam room. Confirm your exact approved reference list against the current PSI bulletin before test day rather than assuming last year's list still applies - code editions and reference assignments can be updated, and New Mexico's 2024 plumbing/mechanical codes took effect August 1, 2026 with a permit transition running through January 1, 2027. Always verify PSI's assigned exam references directly rather than assuming the exam automatically follows the newest code edition.
Eligibility and Deadlines
Before you can sit for either exam, CID eligibility requirements apply:
- Two years (4,000 hours) of qualifying plumbing experience
- Notarized application and work-experience affidavits
- CID approval of the application
- Minimum age of 18 for certificate issuance
Under the rule amendment effective August 1, 2026, qualifying experience generally must fall within the preceding ten years. Accredited technical-training credit can offset some experience - half a year of experience credit per year of qualifying training - but that credit is capped at half of the total required experience. This is a meaningful detail for career-changers using trade school time to shorten the clock; the full mechanics are covered in NM-JP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Scheduling logistics, testing windows, and how the six-month clock interacts with retake attempts are laid out fully in NM-JP Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Retakes, Validity, and Renewal
If you don't pass on the first try, you're allowed no more than two attempts at the same examination within a 30-day period. That's a tight window, so a failed attempt should trigger immediate, focused review of your weakest domain rather than a rushed re-schedule with no plan.
Once certified, the credential lasts three years, expiring on the last day of the issuance month. Renewal requires 16 approved continuing education hours, with at least eight of those hours specifically on the current applicable code. Build that CE tracking into your calendar early - scrambling for code-hour credits near expiration is avoidable.
For a numbers-driven look at how attempt limits and validity periods affect overall success rates, see NM-JP Pass Rate 2026: What the Data Shows. And if you're still deciding whether the time and fees are worth it long-term, Is the NM-JP Certification Worth It? Complete ROI Analysis 2026 covers that decision in depth.
A Fast Final Review Schedule
If you're using this cheat sheet in the final stretch before your test date, don't spread review evenly across all nine domains - weight it toward Drainage Waste and Vents and the practical task categories, since they carry the most points and the most hands-on risk.
Domain 1 + math fundamentals
- Drill trap arm, vent sizing, and drainage fixture unit problems
- Practice calculator-based sizing math since it's open book but must be done fast
Domains 2, 3, 4, 9
- Water supply sizing, backflow device selection, storm drainage, and sewer/septic slope rules
Domains 5, 6, 7, 8
- Fixture/water heater installation rules, general regulations, interceptors, and isometric drawing practice
Practical drills + full review
- Physically rehearse copper/PEX joints, tub/washer-box assembly, island vent, and minimum-rise setup
- Confirm your reference book tabs and calculator meet the allowed rules
For a structured, week-by-week plan built around first-attempt success rather than just cramming, see the full NM-JP Study Guide 2026: How to Pass on Your First Attempt. You can also run timed practice questions modeled on the real domain weighting at our NM-JP practice test platform to see where your weak spots actually are before test day.
FAQ
You need 53 of 70 points, which is 75%. The practical exam requires 75 of 100 available points.
The application/certificate fee is $75, the written exam is $68.88, and the practical exam is $68.88 - $212.76 total for the application plus one attempt at each component.
No. Both exams are open book, but only approved references with permanent tabs and highlighting, plus a silent nonprinting nonprogrammable calculator, are allowed. Handwritten notes and loose papers are prohibited.
Drainage Waste and Vents is the largest of the nine written domains, so it deserves the most review time, followed by the fixture, water heater, and accessibility content in Domain 5.
You may retake the same exam, but no more than two attempts are allowed within any 30-day period. Passing scores remain valid for one year, though that does not extend your six-month application completion deadline.
Keep this page bookmarked as your quick-reference companion, and pair it with the deeper guides linked above - including NM-JP Certification and NM-JP Training - as you move from general familiarity to exam-day readiness.