- Trade exam costs $66 per attempt; the separate SRE course/exam is $61 through GMetrix.
- 100 scored questions, 240 minutes, 70% passing score - plus 5-10 unscored experimental items.
- Drainage Waste and Vents is the largest domain on the outline - prioritize it first.
- Open-book exam allows the 2018 IPC, IMC, IFGC, NFPA 13/13D/13R, OSHA 1926, and AZ onsite-wastewater rules.
Quick Facts Snapshot
If you only have five minutes before test day, this is the page to reread. The Arizona Registrar of Contractors relies on PSI to administer the C-37/CR-37 Plumbing trade examination, and every logistical detail below comes straight from the current PSI candidate bulletin. Keep this open on a second screen while you run through the full AZ-PLB Exam Domains 2026: Complete Guide to All 13 Content Areas for deeper domain coverage.
| Item | Detail |
|---|---|
| Administering body | PSI, on behalf of the Arizona Registrar of Contractors |
| License scopes | C-37 (commercial only) / CR-37 (commercial + residential) |
| Trade exam fee | $66 per attempt |
| Statutes & Rules Exam (SRE) | $61, online course/exam via GMetrix |
| Scored questions | 100 |
| Unscored experimental questions | 5-10 (blended into the same time block) |
| Time allowed | 240 minutes |
| Passing score | 70% |
| Test format | Computer-based, multiple-choice, test center or remote proctoring |
| Retake wait | 30 days; 90 days after three failed attempts |
Registration & Fee Mechanics
Two separate exams sit between you and a plumbing contractor license in Arizona: the trade exam (C-37 or CR-37) and the Statutes and Rules Exam (SRE). They are administered differently and priced differently, and mixing them up is one of the most common planning mistakes candidates make.
- Trade exam: $66 per attempt, delivered by PSI as a computer-based multiple-choice test. You can sit for it at a physical test center or through remote proctoring.
- SRE: $61, delivered as an online course/exam combination through GMetrix - a different vendor, different format, different content focus (statutes, licensing law, and business rules rather than plumbing code application).
Both exams have to be cleared before you can move forward with licensing, so budget for both fees and both study blocks. For a full cost breakdown across the entire licensing process, see AZ-PLB Certification Cost 2026: Complete Pricing Breakdown. If you're still mapping out testing windows and how far in advance to book, AZ-PLB Exam Dates 2026: Testing Windows, Deadlines & Scheduling walks through the scheduling logistics in detail.
Key Takeaway
Treat the trade exam and the SRE as two separate study projects with two separate fees - don't assume passing one covers the other.
Domain-by-Domain Cheat Sheet
The trade outline is organized into 13 content areas. Rather than studying them in the order they're listed, rank them by weight and by how frequently they show up in real commercial plumbing scope-of-work situations. Drainage Waste and Vents (DWV) is explicitly the largest domain, so it earns the most review time.
Domain 1: Drainage Waste and Vents
The largest domain on the outline. Expect heavy coverage of pipe sizing, slope, venting configurations, and fixture unit calculations pulled from the 2018 IPC.
- Know fixture unit loading tables and minimum vent sizing cold
Domain 2: Indirect Waste
Focuses on when indirect waste connections are required versus direct connections, and how air gaps are sized and verified.
- Distinguish air gap requirements from air break requirements
Domain 3: Water Supply Systems
Covers sizing, materials, and pressure/velocity considerations for potable water distribution in commercial settings.
- Practice pipe sizing scenarios using code-based demand tables
Domain 4: Backflow Prevention
Tests your ability to match backflow assembly types to hazard levels and installation conditions.
- Memorize which device type applies to which hazard classification
Domain 5: Roof Drains and Storm Drainage Systems
Storm drainage sizing based on rainfall rate and roof area, plus secondary/emergency drainage provisions.
- Review scupper and overflow drain requirements
Domain 6: Plumbing Fixtures (including water heaters and accessibility)
Blends fixture installation rules with water heater requirements and accessibility clearances - a domain that rewards cross-referencing multiple code sections.
- Know accessible clearance dimensions and water heater relief valve rules
Domain 7: General Knowledge
A broader domain that can pull from multiple references at once, including general code administration concepts.
- Don't skip this domain just because it sounds vague - it's still scored
Domain 8: Specialty Plumbing, Interceptors, and Traps
Grease interceptors, oil separators, and trap sizing/venting fall here - common in commercial kitchen and industrial scope questions.
- Study interceptor sizing methods, not just placement rules
Domain 9: Fuel Gas
Draws from the 2018 IFGC. Covers gas piping sizing, venting of appliances, and shutoff valve placement.
- Practice gas pipe sizing tables using demand and length
Domain 10: Septic and Sewer
Includes Arizona's listed onsite-wastewater rules alongside standard sewer connection requirements.
- Know how the AZ onsite-wastewater rules differ from generic IPC sewer language
Domain 11: Hydronics
Hydronic heating/cooling piping systems - expect questions on expansion tanks, circulation, and system components.
- Review component function, not just terminology
Domain 12: Fire Sprinklers
Draws directly from NFPA 13 (2016), NFPA 13D (2007), and NFPA 13R (2007) - know which standard applies to which occupancy type.
- Memorize the occupancy-to-standard mapping before test day
Domain 13: Excavation
Ties to OSHA 1926 trench and excavation safety provisions as they apply to plumbing installation work.
- Focus on trench protection and shoring basics from OSHA 1926
For the full breakdown of how these domains interrelate and typical question phrasing, see AZ-PLB Exam Domains 2026: Complete Guide to All 13 Content Areas. If you want a candid read on how these 13 areas compare in real difficulty, check How Hard Is the AZ-PLB Exam? Complete Difficulty Guide 2026.
Approved References & What You Can Bring
This is an open-book exam, but "open book" has specific rules that trip people up. You are allowed to bring the approved reference set, and your personal copies can already contain notes, highlighting, and permanent tabs made before you walk in.
- 2018 IPC (International Plumbing Code)
- 2018 IMC (International Mechanical Code)
- 2018 IFGC (International Fuel Gas Code)
- NFPA 13 (2016) - commercial fire sprinkler systems
- NFPA 13D (2007) - one- and two-family dwelling sprinkler systems
- NFPA 13R (2007) - residential occupancies up to four stories
- OSHA 1926 - construction safety, relevant to the Excavation domain
- Arizona's listed onsite-wastewater rules - relevant to the Septic and Sewer domain
Because remote sessions have tighter restrictions, decide early which format suits your working style. Someone who leans heavily on scratch-paper calculations for pipe sizing or fixture unit math may prefer a physical test center over remote proctoring.
Scoring, Retakes, and Timing
The math on this exam is straightforward once you understand the structure: 100 scored questions determine your result, but PSI may quietly insert 5-10 additional unscored experimental questions within the same 240-minute window. You won't know which questions are experimental, so treat every question as if it counts.
- Passing score: 70% of the 100 scored questions
- Time budget: 240 minutes total, which averages out to roughly 2 minutes per question if experimental items are included
- First failed attempt: 30-day wait before retaking
- After three failed attempts: wait increases to 90 days
That retake structure rewards a deliberate first attempt over a rushed one. For exact score mechanics and how the passing threshold is calculated, review AZ-PLB Passing Score 2026: Exactly What You Need to Pass. And if you want context on what outcomes actually look like across test-takers, AZ-PLB Pass Rate 2026: What the Data Shows lays out what the available data shows without guesswork.
Key Takeaway
Don't burn your first attempt on partial preparation - a 30-day minimum wait after a fail is real lost time on a licensing timeline.
Licensing Path After You Pass
Passing the trade exam isn't the finish line - it's a checkpoint. Arizona requires qualifying parties to generally hold four years of practical or management trade experience, with at least two of those years falling within the preceding ten years. Qualifying technical education can offset up to two of those required years.
Once you pass, the clock starts on your application window: you must apply for the license within two years after passing the exam. After licensure, renewal happens every two years, along with applicable fees, bond requirements, and business-compliance obligations tracked by the Registrar of Contractors.
- Confirm your experience documentation lines up with the ROC's qualifying-party requirements before you schedule the exam
- Track your two-year application deadline immediately after your pass notice arrives
- Plan renewal paperwork and bonding around the two-year cycle so you're not scrambling at expiration
If you're still confirming whether you meet the experience and education thresholds, AZ-PLB Requirements 2026: Eligibility, Prerequisites & How to Qualify breaks down each qualifying path. For a bigger-picture view of whether pursuing this license fits your career goals, see Is the AZ-PLB Certification Worth It? Complete ROI Analysis 2026 and AZ-PLB Salary Guide 2026: Complete Earnings Analysis for how licensed contractors position themselves in the job market, including through listings covered in AZ-PLB Jobs.
One-Week Sprint Review Schedule
If your exam date is close and you need a compressed final review rather than a full study plan, structure your last week around domain weight rather than domain order. This isn't a generic study framework - it's built specifically around which AZ-PLB domains carry the most exam weight and which references they draw from.
Heaviest domain first
- Drill Drainage Waste and Vents fixture unit tables and vent sizing from the 2018 IPC
- Work practice questions on Plumbing Fixtures, including water heater relief valves and accessibility clearances
Code-cluster domains
- Pair Water Supply Systems with Backflow Prevention since both hinge on hazard/pressure logic
- Review Fuel Gas piping sizing tables from the 2018 IFGC
Standards-heavy domains
- Map Fire Sprinklers occupancy types to NFPA 13, 13D, and 13R distinctions
- Cover Excavation safety provisions from OSHA 1926 and Septic and Sewer alongside AZ onsite-wastewater rules
Fill remaining gaps
- Review Indirect Waste, Roof Drains and Storm Drainage, Specialty Plumbing/Interceptors/Traps, Hydronics, and General Knowledge
- Confirm your reference tabs are already placed since you cannot annotate during the exam
For a longer runway plan built from day one of preparation rather than a last-week sprint, the full AZ-PLB Study Guide 2026: How to Pass on Your First Attempt lays out a complete preparation timeline. You can also run timed practice sets on our practice test platform to simulate the 240-minute, 100-question format before you sit for the real thing.
New to the credential itself and want the plain-language basics before diving into cheat-sheet details? Start with What Is AZ-PLB?, AZ-PLB Meaning, or What Does AZ-PLB Stand For? for foundational context, and AZ-PLB Training if you're evaluating prep courses beyond self-study. You can also browse practice questions modeled on the actual domain weighting to see where your knowledge gaps sit before committing to a test date.
FAQs
No. The trade exam ($66 per attempt) is administered by PSI and tests plumbing code knowledge. The SRE ($61) is a separate online course/exam delivered through GMetrix and covers statutes and licensing rules. Both must be passed for licensing.
There are 100 scored questions with a 240-minute time limit. PSI may also include 5-10 additional unscored experimental questions within that same time allowance, so the total question count you see on screen may be slightly higher than 100.
Yes, the exam is open-book using the approved references, including the 2018 IPC, IMC, and IFGC, NFPA 13/13D/13R, OSHA 1926, and Arizona's onsite-wastewater rules. Pre-existing notes, highlighting, and permanent tabs are allowed, but you cannot write in the references or bring loose extra papers during the test.
You must wait 30 days before retaking it. If you accumulate three failed attempts, the required wait before your next attempt increases to 90 days.
Drainage Waste and Vents is the largest domain on the outline, so it's the strongest starting point. From there, prioritize domains tied to standards you're least familiar with, such as Fire Sprinklers (NFPA 13/13D/13R) or Fuel Gas (IFGC).