- You need 64 of 85 scored questions correct (75%) within 180 minutes to pass.
- Vents is the heaviest domain at 13 items; General Plumbing Knowledge, Water Supply, and Drains and Sewers each carry 10.
- PSI charges $92 per exam attempt; the CIB initial application total is $75 ($25 processing + $50 initial license).
- From October 8, 2026 to January 8, 2027 you can choose the old or new code; after January 9, 2027 the 2024-code version is mandatory.
Quick Facts Snapshot
This is the condensed reference sheet for the Oklahoma Plumbing Journeyman and Natural Gas License Exam (OK-PLB) - not the residential-only version, not the standalone natural-gas exam, and not the contractor exam. If you're studying for the full journeyman and gas exam administered through PSI Services LLC under the Oklahoma Construction Industries Board (CIB), the numbers below are the ones that matter.
For a deeper breakdown of what each content area actually tests, see the OK-PLB Exam Domains 2026: Complete Guide to All 10 Content Areas. If you want a difficulty-focused walkthrough instead of a raw fact sheet, read How Hard Is the OK-PLB Exam? Complete Difficulty Guide 2026.
Domain Weight Cheat Sheet
The PSI candidate bulletin lists exact item counts for all 10 domains, totaling 85 scored questions. Use these counts to allocate study time proportionally rather than spreading effort evenly across topics you already know well.
| Domain | Item Count |
|---|---|
| 1. General Plumbing Knowledge and Regulations | 10 |
| 2. Piping, Valves, and Control Valves | 8 |
| 3. Fixtures and Equipment | 8 |
| 4. Water Supply | 10 |
| 5. Drains and Sewers | 10 |
| 6. Vents | 13 |
| 7. Traps, Interceptors, Indirect, and Special Waste | 5 |
| 8. Isometric Analysis | 7 |
| 9. Fuel Gas | 10 |
| 10. Safety | 4 |
Vents (13 items - largest single domain)
Vent sizing, developed length, wet venting, common venting, and stack venting arrangements dominate this section. Because it carries more weight than any other domain, errors here have an outsized effect on your score.
- Practice reading vent diagrams alongside drainage isometrics
- Cross-reference IPC 2018 vent sizing tables with Oklahoma revisions
Isometric Analysis (7 items)
This domain tests your ability to read and interpret plumbing isometric drawings - sizing pipe runs, tracing fixture units, and spotting code violations in a drawn system rather than in text.
- Practice tracing drain-waste-vent paths on sample isometrics
- Pair this domain's review with Vents and Drains and Sewers, since questions often overlap conceptually
For a full explanation of how these ten areas connect and why some carry more weight, revisit the OK-PLB Exam Domains 2026 guide. If you're still deciding whether the 75% threshold changes how you should prepare, the OK-PLB Passing Score 2026 breakdown walks through exactly what 64 correct answers means in practice.
Fees, Applications, and Scheduling
Money and paperwork trip up more candidates than the exam content does. Here's the sequence, straight from CIB and PSI documentation.
- CIB application total: $75 - $25 processing fee plus $50 initial license fee, submitted before you're eligible to schedule.
- PSI exam fee: $92 per exam portion and per attempt.
- Approval order matters: CIB approval must happen before PSI scheduling - you cannot book a seat first and sort out eligibility later.
- Eligibility: applicants must be at least 18, with three years of verifiable plumbing experience under a licensed contractor (an experience year equals 2,000 hours), unless approved education substitutes - 1,000 classroom hours for two years, or 500 hours for one year.
- Alternate routes: qualifying military and out-of-state experience are accepted, but only subject to CIB approval - don't assume automatic credit.
For the full itemized cost picture - including how the $75 application and $92 PSI fee stack up against retake costs - see OK-PLB Certification Cost 2026: Complete Pricing Breakdown. If you're still confirming you meet the experience and education thresholds, check OK-PLB Requirements 2026: Eligibility, Prerequisites & How to Qualify before you spend a dollar on scheduling.
Code Version and Reference Materials
Code editions are where a cheat sheet earns its keep, because this is the detail most candidates get wrong. The blueprint source is the Board-linked PSI bulletin effective December 18, 2025 - despite carrying a 2023 filename, so don't dismiss it as outdated.
Key Takeaway
From October 8, 2026 through January 8, 2027, candidates taking the full Plumbing Journeyman and Gas exam may choose either the previous code or the newly adopted 2024-code version. Starting January 9, 2027, the 2024-code exam becomes mandatory. These dates apply specifically to this exam and differ from the September 14, 2026 construction-code effective date and from the residential and standalone natural-gas exam transitions - do not mix them up.
The listed code references are IPC 2018 and IFGC 2018 with Oklahoma revisions, along with the authorized plumbing-mathematics reference and OSHA construction reference. Match every practice question and code citation to the specific exam version you've selected - studying the wrong edition's vent tables or gas piping sizing charts wastes hours you don't have. For exact registration windows and how the code-choice period affects when you should schedule, see OK-PLB Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Exam-Day Rules and Retake Timing
This is an open-book exam, but "open-book" comes with restrictions that trip up first-time test-takers.
- Allowed: advance highlighting in your reference books, permanent tabs, and a silent, nonprinting, nonprogrammable calculator.
- Prohibited: handwritten reference notes and loose papers - anything not permanently bound into your approved reference material.
- Time structure: 180 minutes for 85 scored questions, plus up to 10 unscored experimental questions that don't count against your clock per the bulletin.
If you want a realistic sense of how tough this exam is relative to your background, read How Hard Is the OK-PLB Exam?, and for context on outcomes across attempts, see OK-PLB Pass Rate 2026: What the Data Shows.
Licensing, Renewal, and Continuing Education
Passing the exam isn't the finish line - it's the start of a renewal cycle you need to plan around.
- Annual renewal fee: $75.
- Expiration date: the last day of the licensee's birth month, every year.
- Continuing education: six approved hours required every 36 months.
- New-license exemption: licensees are exempt from CE for three years after passing the current licensing examination.
Journeymen operate under a licensed plumbing contractor's supervision rather than pulling their own permits or contracts. If you're weighing whether the license is worth pursuing given the ongoing renewal and CE obligations, Is the OK-PLB Certification Worth It? Complete ROI Analysis 2026 lays out the tradeoffs, and OK-PLB Salary Guide 2026 covers earnings context for licensed journeymen in the field.
One-Week Cram Schedule by Domain
If you're using this cheat sheet in the final stretch before your exam date, allocate days by item weight rather than by personal preference. This isn't a generic study method - it's built directly from the 85-question breakdown above.
Vents (13 items) + Isometric Analysis (7 items)
- Drill vent sizing tables against IPC 2018 with Oklahoma revisions
- Practice tracing isometric drawings for vent and drain paths together, since the domains overlap conceptually
Water Supply, Drains and Sewers, Fuel Gas (10 items each)
- Review IFGC 2018 gas piping sizing and appliance venting for Fuel Gas
- Confirm you're studying the correct code edition for your selected exam version
General Plumbing Knowledge and Regulations (10 items)
- Review CIB rules, licensing scope, and Oklahoma-specific administrative code sections
- Practice locating answers quickly in your tabbed references - speed matters under the 180-minute limit
Piping, Valves, and Control Valves + Fixtures and Equipment (8 items each)
- Focus on valve types, control functions, and fixture installation clearances
- Time yourself answering practice sets to simulate the open-book pace
Traps, Interceptors, Indirect and Special Waste (5) + Safety (4)
- These are lower-weight domains - review core definitions and move on
- Don't over-invest time here at the expense of Vents or Water Supply
Full Practice Run
- Sit a full-length timed practice exam mirroring the 85-question, 180-minute format
- Review missed questions by domain and re-tab your references accordingly
For a longer-horizon prep plan rather than a last-week cram schedule, see OK-PLB Study Guide 2026: How to Pass on Your First Attempt. You can run full-length, timed practice sets that mirror the actual PSI format over at our practice test platform, which is built around this exact 85-question, 10-domain structure.
FAQ
The exam has 85 scored questions with a 180-minute time limit. Up to 10 additional unscored experimental questions may also appear, but per the bulletin, time spent on those doesn't count against your 180 minutes.
You need 75%, which means 64 correct answers out of 85 scored questions.
No. Handwritten reference notes and loose papers are prohibited. You can use advance highlighting and permanent tabs in your approved reference books, plus a silent, nonprinting, nonprogrammable calculator.
It depends on your test date. From October 8, 2026 through January 8, 2027, you can choose the previous code or the newly adopted 2024-code version. Starting January 9, 2027, the 2024-code exam is mandatory. Match your practice materials to whichever version you select.
After a first failure, you must wait 30 days before retesting. After a second failure or more, the wait is 90 days. Each attempt requires a new $92 PSI fee.
For more on how to structure your prep around these exact rules, see the OK-PLB Study Guide 2026, or check OK-PLB Requirements 2026 to confirm your eligibility before you schedule.