Current Mississippi Plumbing format: 70 scored questions, 3 hours, and 70% required to pass. That means 49 correct scored answers. DWV is the largest current PSI topic with 15 questions, followed by 12 Isometric Analysis questions.
What Is the Mississippi Plumbing Contractor Exam?
The Mississippi Plumbing trade examination is a PSI contractor test used in the Mississippi State Board of Contractors licensing process for commercial and residential plumbing work within the classification scope.
The current trade exam is based on plumbing systems and code application, not fuel-gas or boiler systems. The biggest emphasis falls on DWV and isometric analysis, which together make up 27 of the 70 scored questions.
Trade exam answer: 70 scored questions, 3 hours, 70% passing and open-book testing.
Main code answer: the current PSI plumbing reference is the 2021 International Plumbing Code.
Licensing answer: the normal contractor path also requires the Mississippi Law and Business Management exam and MSBOC approval before PSI scheduling.
This page uses the exact current PSI plumbing blueprint and the exact three approved trade references.
The authority strategy uses 10 official Mississippi/PSI authority sources and sections, with contextual links across exam, licensing, reciprocity, renewal and contractor topics.
Mississippi Plumbing Contractor Exam Domains
Match your Mississippi plumbing contractor exam prep time to the current PSI blueprint.
| Exam Area | What to Study | Exam Weight |
|---|---|---|
| Drain, Waste and Vent | Sanitary drainage, pipe sizing, slope, stacks, branches, vent systems, fixture units and code application | 15 questions | 21.4% |
| Isometric Analysis | Reading isometric drawings, fixture units, flow direction, developed length, pipe sizing and system layout | 12 questions | 17.1% |
| Water Supply | Water service, distribution, sizing, pressure, fixture-unit demand and potable-water systems | 6 questions | 8.6% |
| Fixtures and Equipment | Fixture installation, clearances, connections, required fixtures and related equipment | 5 questions | 7.1% |
| General Plumbing Regulations | General IPC requirements, permits, materials, installation rules and code administration | 4 questions | 5.7% |
| Safety | OSHA construction safety, trenching, PPE, ladders, tools and jobsite safety | 4 questions | 5.7% |
| Cleanouts | Required locations, access, sizing and installation | 4 questions | 5.7% |
| Traps and Interceptors | Trap requirements, trap seals, interceptors, separators and prohibited arrangements | 4 questions | 5.7% |
| Piping, Valves and Controls | Pipe materials, valves, control devices and installation requirements | 3 questions | 4.3% |
| Hangers and Supports | Pipe support intervals, hangers, anchoring, protection and structural considerations | 3 questions | 4.3% |
| Backflow | Backflow prevention, air gaps, cross-connection protection and potable-water safety | 3 questions | 4.3% |
| Joints and Connections | Approved joining methods, fittings, transitions and connection requirements | 3 questions | 4.3% |
| Water Heaters | Installation, relief protection, clearances and water-heater code requirements | 2 questions | 2.9% |
| Developed Length | Measuring system length through fittings and applying developed length to sizing problems | 2 questions | 2.9% |
Mississippi Plumbing Contractor Exam Breakdown
Trade ClassificationPlumbing
Trade Exam Questions70 scored questions
Trade Exam Time3 hours | 180 minutes
Passing Score70% | 49 correct scored answers
Testing ProviderPSI
Licensing AuthorityMississippi State Board of Contractors
Exam FormatComputer-based, open book
Main Code2021 International Plumbing Code
Largest Trade TopicDrain, Waste and Vent | 15 questions
Second-Largest TopicIsometric Analysis | 12 questions
Law and Business Exam50 questions | 2 hours | 70% passing
Exam EligibilityMSBOC approval required before PSI scheduling
Mississippi Plumbing Contractor Licensing Path
Passing the Plumbing trade exam is one part of the Mississippi contractor licensing process.
Application first: apply with the Mississippi State Board of Contractors before scheduling the trade exam.
Qualifying party: the contractor business designates the person responsible for satisfying the examination requirements.
Trade exam: Plumbing | 70 scored questions | 3 hours | 70% passing.
Business and Law: the normal commercial or residential contractor path also requires the Mississippi Law and Business Management examination.
Eligibility window: current PSI guidance provides a six-month examination eligibility period after approval.
What Is on the Mississippi Plumbing Contractor Exam?
Each bar is scaled against Drain, Waste and Vent, the largest 15-question category.
Drain, Waste and Vent15 questions
Isometric Analysis12 questions
Water Supply6 questions
Fixtures and Equipment5 questions
General Plumbing Regulations4 questions
Safety4 questions
Cleanouts4 questions
Traps and Interceptors4 questions
Piping, Valves and Controls3 questions
Hangers and Supports3 questions
Backflow3 questions
Joints and Connections3 questions
Water Heaters2 questions
Developed Length2 questions
Current Mississippi Plumbing Contractor Exam References
The current PSI bulletin lists three approved trade references.
| Reference | Primary Use | Current PSI Listing |
|---|---|---|
| International Plumbing Code | Core plumbing code, DWV, water supply, fixtures, cleanouts, traps, backflow and general regulations | 2021 Edition |
| 29 CFR Part 1926 OSHA | Construction safety | Latest available amendments or PSI selections |
| Mathematics for Plumbers and Pipefitters | Trade math, measurements, formulas and plumbing calculations | Lee Smith | 8th Edition | 2013 |
Your Mississippi Plumbing Contractor Licensing Roadmap
Apply with MSBOC, designate the qualifying party, receive PSI eligibility, prepare the three approved trade references, pass the Plumbing and Business and Law exams, and complete the contractor licensing process.
1
Apply with the Mississippi State Board of Contractors
Submit the contractor application and required business information before examination scheduling.
2
Designate the qualifying party
Identify the owner, officer or responsible managing employee who will satisfy the examination requirements for the business.
3
Receive PSI eligibility
MSBOC sends the approved qualifying party's eligibility to PSI before the candidate can schedule.
4
Prepare the three approved references
Use the 2021 IPC, OSHA Part 1926 and Mathematics for Plumbers and Pipefitters and prepare them within current PSI rules.
5
Study the exact PSI blueprint
Prioritize DWV and isometric analysis first, then water supply, fixtures, regulations, cleanouts, traps, backflow and the remaining trade topics.
6
Pass the trade and Business and Law exams
Complete the required examinations during the current six-month eligibility period.
7
Complete Mississippi contractor licensing
Finish the Board's current financial, insurance, business and renewal requirements that apply to your license type.
Six-Week Mississippi Plumbing Contractor Exam Prep Plan
Week 1
PSI Blueprint and Reference Setup
- Review all 14 trade domains
- Organize the three approved books
- Add permitted permanent tabs
- Take a diagnostic exam
Week 2
DWV
- Drainage sizing
- Slope and fixture units
- Stacks and branches
- Vent systems
Week 3
Isometric Analysis
- Read isometric drawings
- Trace flow direction
- Calculate developed length
- Size piping from drawings
Week 4
Water and Fixtures
- Water supply sizing
- Fixtures and equipment
- Water heaters
- Backflow protection
Week 5
Code Details and Business Law
- Cleanouts
- Traps and interceptors
- Joints, supports and valves
- Mississippi Business and Law
Week 6
Timed PSI Simulation
- 70-question practice exams
- Three-hour pacing
- Reference lookup drills
- Final weak-area review
Mississippi Plumbing Contractor Open-Book Exam Prep Strategy
Do this during exam prep
- Practice with the exact three PSI-listed references
- Use permitted permanent tabs
- Highlight and underline before test day
- Learn the IPC index and key tables
- Practice isometric analysis without guessing
- Complete full 180-minute simulations
Avoid these mistakes
- Studying gas piping as part of this plumbing exam
- Using outdated exam counts or passing scores
- Bringing loose papers or unauthorized notes
- Using temporary removable tabs
- Ignoring DWV and isometrics
- Assuming open book means easy
Open-book strategy: 70 scored questions in 180 minutes averages about 2.57 minutes per question. Identify the topic, choose the right reference, find the rule or formula, confirm the answer and move on.
Mississippi Plumbing Contractor Exam Prep Options
Live Virtual and Self-Study Training
Instructor-Guided Mississippi Exam Prep
- Live virtual instruction
- Recorded class access
- Open-book reference navigation
- Plumbing calculations
- Simulated exam preparation
Mississippi Plumbing Contractor Prep
Trade-Focused PSI Exam Prep
- 2021 IPC review
- DWV and isometric analysis
- OSHA safety
- Plumbing math
- Timed reference lookup
All-Inclusive Licensing Support
Contractor Licensing and Business Setup Support
- Trade exam preparation
- Business and Law preparation
- Application support
- Licensing workflow guidance
- Contractor business setup support
Trade Exam, Business and Law, and Contractor Licensing Are Separate Steps
The Mississippi Plumbing trade exam tests classification-specific plumbing knowledge. Contractor licensing also includes Board approval, a qualifying party and the required Business and Law examination.
· Plumbing trade exam: 70 scored questions
· Three-hour testing limit
· 70% minimum passing score
· Open-book PSI examination
· Separate 50-question Business and Law exam
· MSBOC approval required before PSI scheduling
Mississippi Plumbing Contractor Exam Prep FAQ
Mississippi Plumbing Trade Exam Basics
The current PSI bulletin lists 70 scored questions for the Mississippi Plumbing trade examination.
Candidates receive 3 hours, or 180 minutes, to complete the trade examination.
The current passing score is 70 percent, which means 49 correct scored answers out of 70.
Yes. The current PSI plumbing examination is open book, but candidates must follow PSI rules for approved references, tabs, markings and loose materials.
PSI administers the trade examination after the Mississippi State Board of Contractors approves the applicant and sends examination eligibility.
Drain, Waste and Vent is the largest current PSI category with 15 scored questions.
The current PSI blueprint assigns 12 scored questions to Isometric Analysis.
The current PSI blueprint assigns 6 scored questions to Water Supply.
The current PSI blueprint assigns 5 scored questions to Fixtures and Equipment.
The current PSI blueprint assigns 4 scored questions to General Plumbing Regulations.
The current PSI blueprint assigns 4 scored questions to Safety.
The current PSI blueprint assigns 4 scored questions to Cleanouts.
The current PSI blueprint assigns 4 scored questions to Traps and Interceptors.
The current PSI blueprint assigns 3 scored questions to Piping, Valves and Controls.
The current PSI blueprint assigns 3 scored questions to Hangers and Supports.
The current PSI blueprint assigns 3 scored questions to Backflow.
The current PSI blueprint assigns 3 scored questions to Joints and Connections.
The current PSI blueprint assigns 2 scored questions to Water Heaters.
The current PSI blueprint assigns 2 scored questions to Developed Length.
References and Open-Book Rules
The current PSI bulletin lists three approved trade references: the 2021 International Plumbing Code, 29 CFR Part 1926 OSHA, and Mathematics for Plumbers and Pipefitters, 8th Edition.
Yes. PSI permits approved references to be highlighted, underlined and permanently indexed before testing. Temporary removable tabs are not allowed.
No. PSI prohibits loose papers and unauthorized attached materials in exam references.
Business and Law, Approval and Licensing
For the normal commercial or residential contractor licensing path, the Mississippi Law and Business Management examination is mandatory in addition to the trade exam when a trade test is required.
The current PSI bulletin lists 50 questions, 2 hours and a 70 percent passing requirement for the Mississippi Law and Business Management examination.
Yes. Applicants first apply with the Mississippi State Board of Contractors. After approval, the Board sends the qualifying party's eligibility to PSI for scheduling.
The qualifying party is the person designated to satisfy the examination requirements for the contractor business, typically an owner, officer or responsible managing employee who meets Board requirements.
The current PSI bulletin provides a six-month examination eligibility period for a new applicant to complete the required examinations.
Candidates may retest during the six-month eligibility period under the current PSI process. If the required exams are not passed within that period, the applicant must reapply with the Board.
No. Current MSBOC reciprocity guidance treats reciprocity as a possible trade-exam waiver only. It does not eliminate the contractor application process or the Mississippi Business and Law examination.
Current MSBOC guidance treats contractor licenses as annual licenses that must be renewed each year.
No blanket rule should be assumed for every plumbing contractor. MSBOC's statewide continuing-education rule specifically applies to qualifying parties for certain residential licenses, so candidates should verify the rule for their license type.
Start with Drain, Waste and Vent, then Isometric Analysis, followed by Water Supply, Fixtures and Equipment, regulations, cleanouts, traps and interceptors, backflow, piping, supports, joints, water heaters and developed length.
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Mississippi Plumbing Live and Self-Study Exam Prep Mississippi All-Inclusive Plumbing Licensing Support Current Mississippi PSI Contractor Bulletin Mississippi Contractor Testing Information Mississippi Contractor Licensing Information Mississippi Qualifying Party Requirements Mississippi Contractor Reciprocity Guidance Mississippi Contractor License Maintenance Mississippi Continuing Education Guidance Mississippi Commercial Contractor Laws and Rules Contact 1 Exam Prep
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