Mississippi Plumbing Specialty Contractor • MSBOC • PSI • 70 Questions • 180 Minutes • 70% Passing • 2021 IPC
Ready to become a licensed Mississippi Plumbing Contractor? This guide explains the Plumbing specialty classification, PSI trade examination, Mississippi State Board of Contractors licensing process, approved plumbing reference books, plumbing calculations, and study materials from Contractor Exam Preps.
The Mississippi Plumbing Contractor license is regulated by the Mississippi State Board of Contractors, also known as MSBOC.
Mississippi officially lists Plumbing as a specialty contractor classification.
This classification involves installing, repairing, maintaining, and extending plumbing systems in commercial and residential buildings.
Plumbing contractors work with water-supply piping, sanitary drainage, venting, plumbing fixtures, storm drainage, and related systems.
They help make sure clean water enters a building safely and wastewater leaves without creating health problems.
It may not sound glamorous, but most buildings become very uncomfortable when their plumbing stops working!
The official MSBOC Plumbing classification covers a broad range of plumbing activities.
The state's classification definition includes sanitary drainage, storm drainage, vents, public and private water supplies, septic tanks, drainage and supply wells, swimming pool piping, and irrigation systems.
It also includes certain specialty piping and related services within the classification's legal scope.
However, there is one important examination distinction.
The PSI Plumbing trade examination is described as covering unlimited commercial and residential plumbing without fuel-gas or boiler systems.
Candidates should not confuse this test with the separate Mississippi Mechanical Contractor examination or Residential Plumbing examination.
Those examinations have different subject outlines and reference requirements.
For the Plumbing specialty trade exam, applicants are tested on plumbing installation knowledge, code compliance, safety, calculations, and the ability to read piping drawings.
The current Mississippi Plumbing examination contains 70 scored questions.
Candidates receive three hours, or 180 minutes, to finish the examination.
A minimum score of 70% is required.
That means at least 49 of the 70 scored questions must be answered correctly.
PSI may also administer a small number of unscored experimental questions in accordance with its candidate bulletin.
The 70-question figure refers to the scored examination.
The test is open book, but only approved reference materials are permitted inside the examination center.
Candidates must bring their own approved books.
References may be highlighted, underlined, and permanently indexed before examination day.
Loose papers, removable sticky-note tabs, inserted reference sheets, and writing in books during the examination are not permitted.
The approved references are inspected according to current PSI rules.
These rules make reference-book preparation important.
An open-book exam is not a contest to see who can carry the biggest stack of books.
It is a test of whether candidates understand plumbing and can locate the correct code requirement efficiently.
The Mississippi Plumbing Contractor trade examination lists three approved references.
The first is the 2021 International Plumbing Code.
This is the primary code reference for plumbing fixtures, water distribution, sanitary drainage, venting, traps, cleanouts, backflow protection, piping materials, and installation requirements.
The second reference is OSHA 29 CFR Part 1926.
This book covers federal construction-safety requirements such as excavation safety, ladders, scaffolding, personal protective equipment, tools, equipment, and workplace hazards.
The third book is Mathematics for Plumbers and Pipefitters, 8th Edition, by Lee Smith.
This reference supports the calculations required for plumbing and pipefitting work.
It covers measurements, fractions, decimals, ratios, geometry, pipe layouts, offsets, areas, volumes, and pressure-related mathematics.
Contractor Exam Preps offers the Mississippi Plumbing Contractor Exam Book Package.
This package brings together all three listed trade references.
The package contains standard books that applicants can organize for their own examination preparation.
Professional highlighting and tabbing are not included with the standard book package.
That makes it a useful option for experienced plumbing professionals who prefer to prepare their own reference books.
For structured online learning, Contractor Exam Preps also offers the Mississippi PSI Plumbing Contractor Online Course.
The course includes study strategies, practice-oriented instruction, reference-navigation guidance, printable questions, and one year of online access.
It is compatible with Android and iOS devices, allowing candidates to review lessons from their phone or other supported device.
The online course focuses on the plumbing trade examination.
The three reference books must be obtained separately unless a purchased package specifically includes them.
Mississippi contractor applicants must also complete the separate Law and Business Management examination.
The current PSI bulletin identifies 50 scored questions for this exam.
Candidates are allowed two hours.
The passing score is 70%, requiring 35 correct scored answers.
The approved business reference is the Mississippi edition of the NASCLA Contractor's Guide to Business, Law and Project Management, 6th Edition.
Contractor Exam Preps sells the Mississippi NASCLA Contractor's Guide, 6th Edition.
Candidates can also use the Mississippi PSI Law and Business Management Online Practice Questions.
These products help prepare for licensing, estimating, contracts, lien law, financial management, taxes, labor laws, and project management.
The Plumbing trade examination has 14 technical subject categories.
The largest category is Drain, Waste and Vent.
This section contains 15 questions.
It tests knowledge of sanitary drainage piping, fixture units, slopes, branches, stacks, building drains, venting requirements, and related code provisions.
Drainage systems carry wastewater away from plumbing fixtures.
Venting systems support proper drainage operation and help protect fixture trap seals.
These systems must work together.
If the drainage piping is too small, incorrectly sloped, or improperly vented, problems may develop even when individual fixtures look correctly installed.
The second-largest category is Isometric Analysis, with 12 questions.
Isometric drawings help show how pipes, fixtures, vertical stacks, and horizontal branches connect in three dimensions.
Candidates may need to identify drainage relationships, calculate developed lengths, determine flow direction, or interpret fixture connections.
Drain, Waste and Vent and Isometric Analysis together represent 27 of the 70 scored questions.
That is approximately 38.6% of the examination.
For many applicants, those two subjects should receive the greatest amount of study time.
Water Supply accounts for six questions.
Study water service piping, water distribution, available pressure, fixture demand, backflow prevention, and code sizing methods.
Fixtures and Equipment account for five questions.
These subjects include plumbing fixtures, installation requirements, connections, clearances, and equipment provisions.
Four questions cover General Plumbing Regulations.
Those questions may address materials, prohibited practices, testing, protection, installation requirements, and general code compliance.
Four questions cover Safety.
Safety preparation includes OSHA rules and practical construction jobsite hazards.
Cleanouts account for four questions.
Review where cleanouts are required, access provisions, and maintenance considerations.
Traps and Interceptors account for four questions.
Learn trap requirements, trap seals, interceptors, and proper plumbing waste arrangements.
Several smaller topics are still important.
Piping, Valves and Controls includes three questions.
Hangers and Supports includes three.
Backflow includes three.
Joints and Connections includes three.
Water Heaters includes two.
Developed Length includes two.
These categories complete the published 70-question examination outline.
Even though some subjects contain only two or three questions, candidates should not ignore them.
Every scored question can affect the final result.
Good exam preparation combines practical knowledge with repeated use of the approved books.
Start with the 2021 International Plumbing Code.
Learn where its main chapters, definitions, tables, and special requirements appear.
Practice searching by the subject of the question instead of guessing a section number.
For example, a question about the number of drainage fixture units may require a code table.
A question about a vent terminal may require a venting provision.
A question about trench protection should direct attention to OSHA construction safety.
A question about pipe offsets or dimensions may lead to the mathematics reference.
The better candidates understand the purpose of each book, the faster they can locate useful information.
Practice plumbing mathematics regularly.
Learn how to convert fractions and decimals, work with feet and inches, calculate developed lengths, and solve geometry problems.
Review water pressure, volume, measurements, and pipefitting offsets.
Work through isometric drawings until identifying the relationships between vertical and horizontal piping becomes more comfortable.
Then begin taking timed practice examinations.
Seventy scored questions in 180 minutes allow an average of approximately 2.57 minutes per question.
That means spending six or seven minutes searching for one answer can quickly reduce the time available for the rest of the exam.
The goal is to find the correct information efficiently while maintaining accuracy.
Mississippi licensing involves more than examination performance.
Applicants must first submit a contractor license application to MSBOC.
The application identifies the business, its proposed classification, and its qualifying party.
The qualifying party is the person designated to satisfy required examination qualifications for the contractor business.
Depending on the business structure, the qualifying party may be an owner, officer, or responsible managing employee.
MSBOC reviews the application and notifies PSI when the applicant is eligible to test.
PSI then sends examination scheduling information.
Candidates cannot schedule before their eligibility has been established.
Under published testing guidance, new applicants normally have six months to complete the required examinations.
If required testing is not finished during the eligibility period, another application may be necessary.
After the required examinations are passed and the application is complete, MSBOC performs its final review.
Passing the examination does not automatically issue a contractor license.
Mississippi contractor licenses are generally valid for one year and must be renewed annually.
Contractors also need to follow insurance, business-registration, permit, safety, tax, and inspection requirements that apply to their work.
Project location matters because local plumbing codes, permits, inspections, and utility requirements may differ.
One more important distinction concerns Mississippi's Residential Plumbing classification.
Residential Plumbing is a separate license classification and has a different PSI exam blueprint.
The Plumbing specialty exam described in this article is the 70-question, three-hour examination.
Applicants should confirm their intended project scope before selecting a license classification or purchasing study materials.
This guide includes the Mississippi Plumbing licensing pathway, full PSI topic breakdown, approved reference books, trade mathematics, a piping-system diagram, exam strategies, contractor responsibilities, related Contractor Exam Preps products, interactive FAQs, and a real 1ExamPrep YouTube video.
Important Mississippi Plumbing Contractor 2026 Update: The current PSI Plumbing specialty examination contains 70 scored questions, allows three hours, and requires 70% passing, or 49 correct scored answers. Drain, Waste and Vent is the largest subject with 15 questions, followed by Isometric Analysis with 12 questions. The three approved references are the 2021 International Plumbing Code, OSHA 29 CFR Part 1926, and Mathematics for Plumbers and Pipefitters, 8th Edition. The PSI Plumbing trade exam specifically excludes fuel-gas and boiler systems. The separate Mississippi Law and Business Management examination contains 50 questions, allows two hours, and requires 70% passing. MSBOC application approval is required before PSI scheduling.
A Mississippi Plumbing Contractor is a business or qualifying contractor licensed under the Plumbing specialty classification administered by MSBOC.
The classification involves commercial and residential plumbing work, including installation, maintenance, and repair of plumbing systems.
Plumbing contractors may work with domestic water systems, sanitary drainage, vents, storm drains, fixtures, pipe supports, valves, pumps, and related equipment.
The official classification definition also identifies additional piping and specialty systems within the broader legal scope.
The license covers the types of work authorized by the Board, not every construction service a business might offer.
For example, electrical and mechanical work may involve separate licensing classifications or additional requirements.
Mississippi's Plumbing PSI trade examination covers commercial and residential plumbing without fuel-gas or boiler systems.
Contractors must also understand safety, estimating, supervision, permits, inspections, and applicable construction regulations.
Operating a plumbing company is different from performing one plumbing installation.
Business owners need to manage jobs, employees, schedules, materials, customer agreements, and compliance requirements.
That is why Mississippi generally requires the separate Law and Business Management examination in addition to the plumbing trade examination.
Official classification: Plumbing.
Licensing board: Mississippi State Board of Contractors.
Trade exam provider: PSI.
Trade scope tested: Commercial and residential plumbing without fuel-gas or boiler systems.
Separate requirement: Mississippi Law and Business Management examination.
| Step | Requirement | What to Prepare |
|---|---|---|
| State | Mississippi | Confirm the planned work location and project type. |
| Official Classification | Plumbing | Choose the correct specialty license category. |
| Licensing Authority | MSBOC | Review the current contractor application. |
| Testing Provider | PSI | Schedule only after Board approval. |
| Contractor Business | Applicant Entity | Provide correct business identification. |
| Qualifying Party | Required | Identify the qualifying owner, officer, or employee. |
| Business Relationship | Board Rules Apply | Provide supporting qualifying-party information. |
| Experience Documentation | Application Review | Document relevant plumbing projects and responsibilities. |
| Financial Information | As Applicable | Submit the financial documents requested by MSBOC. |
| Insurance Records | As Applicable | Provide current coverage documentation. |
| Board Application | Required | Submit a complete contractor license application. |
| Examination Eligibility | MSBOC Approval | Wait for PSI authorization. |
| Exam Scheduling | PSI Appointment | Follow the emailed scheduling instructions. |
| Trade Examination | 70 Questions | Study all 14 PSI topics. |
| Trade Exam Time | 180 Minutes | Practice three-hour examinations. |
| Trade Passing Score | 70% | Answer at least 49 scored questions correctly. |
| Trade Exam Format | Open Book | Bring permitted reference books. |
| Code Reference | 2021 IPC | Practice plumbing code lookups. |
| Safety Reference | OSHA 29 CFR 1926 | Review relevant construction hazards. |
| Mathematics Reference | Lee Smith, 8th Edition | Practice plumbing and pipefitting calculations. |
| Trade Books | Three Approved References | Confirm approved titles and editions. |
| Business Exam | Required | Prepare for Mississippi Law and Business Management. |
| Business Questions | 50 | Study licensing, contracts, finance, taxes, and management. |
| Business Exam Time | 120 Minutes | Take timed business practice exams. |
| Business Passing Score | 70% | Answer at least 35 scored questions correctly. |
| Business Reference | Mississippi NASCLA, 6th Edition | Review the approved state business manual. |
| Examination Eligibility Window | Generally Six Months | Complete assigned testing on time. |
| Final Board Review | Required | Resolve all outstanding licensing conditions. |
| License Validity | One Year | Track issuance and expiration dates. |
| Renewal | Annual | Renew through MSBOC before expiration. |
| Residential Plumbing | Separate Classification | Do not confuse it with the Plumbing trade exam. |
The current published PSI candidate bulletin identifies the Plumbing trade examination as a 70-question, three-hour, open-book exam with a 70% passing requirement.
| Exam Detail | Category | Published Information |
|---|---|---|
| Official Trade Name | License | Plumbing |
| State | License | Mississippi |
| Regulator | Authority | Mississippi State Board of Contractors |
| Exam Provider | Testing | PSI |
| Trade Questions | Testing | 70 Scored Questions |
| Trade Time | Testing | 180 Minutes |
| Passing Percentage | Testing | 70% |
| Correct Scored Answers Needed | Testing | 49 |
| Exam Format | Testing | Computer-Based and Open Book |
| Experimental Items | Testing | Possible Additional Unscored Questions |
| Approved Code | Reference | 2021 International Plumbing Code |
| Safety Book | Reference | OSHA 29 CFR Part 1926 |
| Trade Math Book | Reference | Mathematics for Plumbers and Pipefitters, 8th Edition |
| Approved Trade References | Reference | Three |
| Personal Approved Books | Reference | Candidate Must Bring Them |
| Permanent Tabs | Reference | Permitted Under PSI Conditions |
| Temporary Tabs | Reference | Not Permitted |
| Pre-Exam Highlighting | Reference | Permitted |
| Loose Notes | Reference | Not Permitted |
| Silent Calculator | Reference | Nonprinting, Nonprogrammable Calculator Permitted |
| Drain, Waste and Vent | Blueprint | 15 Questions |
| Isometric Analysis | Blueprint | 12 Questions |
| Water Supply | Blueprint | 6 Questions |
| Fixtures and Equipment | Blueprint | 5 Questions |
| General Regulations | Blueprint | 4 Questions |
| Safety | Blueprint | 4 Questions |
| Cleanouts | Blueprint | 4 Questions |
| Traps and Interceptors | Blueprint | 4 Questions |
| Piping, Valves and Controls | Blueprint | 3 Questions |
| Hangers and Supports | Blueprint | 3 Questions |
| Backflow | Blueprint | 3 Questions |
| Joints and Connections | Blueprint | 3 Questions |
| Water Heaters | Blueprint | 2 Questions |
| Developed Length | Blueprint | 2 Questions |
| Fuel Gas | Scope | Excluded From This Trade Exam |
| Boiler Systems | Scope | Excluded From This Trade Exam |
| Law and Business Questions | Business | 50 Scored Questions |
| Law and Business Time | Business | 120 Minutes |
| Law and Business Passing | Business | 70%, 35 Correct |
| Business Reference | Business | Mississippi NASCLA Guide, 6th Edition |
| License Renewal | Business | Annual |
Plumbing trade: 70 scored questions, 180 minutes, 49 correct to pass.
Business and Law: 50 scored questions, 120 minutes, 35 correct to pass.
Trade references: 2021 IPC, OSHA, and Mathematics for Plumbers and Pipefitters.
Exam preparation: Prioritize DWV and isometric analysis.
The current PSI Plumbing examination contains 14 subject categories. The following question counts come from the official PSI outline.
Study sanitary drainage systems, pipe sizing, drainage slopes, horizontal branches, stacks, building drains, fixture units, vent sizing, and code-compliant vent arrangements.
Practice interpreting three-dimensional piping diagrams. Trace flow paths, fixture connections, developed lengths, vertical stacks, horizontal branches, and pipe sizing.
Review water services, water distribution, fixture demand, available pressure, pipe sizing, potable water requirements, and supply arrangements.
Study plumbing fixture requirements, fixture installations, connections, clearances, supports, and related plumbing equipment.
Review general code requirements, materials, workmanship, testing, inspections, definitions, prohibited installations, and pipe protection.
Study OSHA 29 CFR Part 1926, including excavation hazards, ladders, scaffolding, personal protective equipment, jobsite tools, and material handling.
Review drainage system cleanout locations, access requirements, permitted arrangements, and maintenance considerations.
Study trap seals, trap requirements, grease interceptors, separators, and approved plumbing waste arrangements.
Review piping-system components, valves, equipment controls, approved uses, and installation requirements.
Study pipe-support methods, hanger placement, attachment, spacing, and protection against movement or damage.
Review cross-connection protection, air gaps, vacuum breakers, backflow prevention devices, and potable-water safety.
Study approved pipe joining methods, compatible materials, transitions, fittings, and code-compliant connections.
Review water heater installations, connections, safety requirements, temperature and pressure relief provisions, and equipment protection.
Practice determining total piping length along the centerline, including changes in direction and relevant pipefitting measurements.
Largest topic: Drain, Waste and Vent, 15 questions.
Second-largest: Isometric Analysis, 12 questions.
Combined: 27 of 70 questions, approximately 38.6%.
Exam scope: Plumbing without fuel-gas or boiler systems.
Start by downloading the official Mississippi PSI Candidate Information Bulletin.
Read the Plumbing examination outline, approved reference list, and reference-book rules.
Next, gather the three approved books.
Organize your International Plumbing Code, OSHA Part 1926, and Mathematics for Plumbers and Pipefitters.
Begin studying with Drain, Waste and Vent.
This is the largest trade topic, with 15 questions.
Review drainage slopes, fixture units, pipe sizing, vent systems, cleanouts, stacks, and building drains.
Then focus on Isometric Analysis.
Practice reading piping diagrams, understanding system layouts, identifying fixture connections, and calculating developed lengths.
Next, review Water Supply.
Study water service piping, distribution systems, sizing, pressure, fixture demand, and backflow protection.
Continue with plumbing fixtures, water heaters, traps, interceptors, valves, hangers, supports, and joints.
Practice OSHA safety questions using the actual construction regulations.
Important safety subjects include excavation hazards, ladders, scaffolds, protective equipment, and material handling.
Practice mathematics regularly.
Use the 8th Edition of Mathematics for Plumbers and Pipefitters for measurement conversions, geometry, pipe offsets, areas, volumes, and pressure calculations.
Then prepare for the Mississippi Law and Business Management examination separately.
Review contractor licensing, estimating, financial management, contracts, tax laws, labor laws, project management, and lien law.
Use the Mississippi PSI Plumbing Contractor Online Course for additional structured review.
During the final week, practice 70-question tests using a 180-minute timer.
Review incorrect answers and improve how quickly you locate the supporting code rule.
Highest priority: DWV, 15 questions.
Second priority: Isometric Analysis, 12 questions.
Core code: 2021 IPC.
Additional references: OSHA Part 1926 and plumbing mathematics.
Final practice: 70 scored questions in three hours.
The following simplified diagram shows how water supply, plumbing fixtures, sanitary drainage, traps, and venting connect within a building.
Understanding these connections helps candidates prepare for both Drain, Waste and Vent and Isometric Analysis questions.
Simplified educational illustration only. Actual plumbing installations must follow applicable codes and approved designs.
Verify that the MSBOC Plumbing specialty classification matches your intended commercial or residential plumbing work.
Gather ownership information, business records, project experience, financial documents, and required supporting information.
Identify the person who will satisfy the applicable examination requirements for the company.
Wait for the Board to send eligibility information to PSI before scheduling.
Prepare the 2021 International Plumbing Code, OSHA Part 1926, and Mathematics for Plumbers and Pipefitters.
Study the 14 plumbing topics and the separate Mississippi Law and Business Management subjects.
Earn at least 49 correct answers on Plumbing and 35 on Law and Business Management.
Finish final Board review, receive your license, and maintain applicable contractor requirements.
The percentages below are calculated from the current PSI Plumbing trade examination blueprint of 70 scored questions.
Total: 70 scored questions.
Passing: 70%, requiring 49 correct answers.
Largest two categories: DWV and Isometric Analysis.
Combined: 27 questions, approximately 38.6% of the examination.
Source: PSI Mississippi Plumbing content outline.
The Plumbing examination is open book, but only the three approved trade references listed by PSI are permitted.
The Mississippi Law and Business Management examination has its own separate approved reference.
| Reference Book | Edition | Purpose |
|---|---|---|
| International Plumbing Code | 2021 | Plumbing fixtures, water distribution, drainage, venting, traps, cleanouts, backflow, piping materials, testing, and installation requirements. |
| Code of Federal Regulations, OSHA Construction Standards | 29 CFR Part 1926, Latest Permitted Amendments | Excavation safety, protective equipment, ladders, scaffolding, jobsite hazards, tools, and construction worker safety. |
| Mathematics for Plumbers and Pipefitters, Lee Smith | 8th Edition, 2013 | Measurements, fractions, decimals, conversions, geometry, pipe calculations, offsets, volumes, areas, and pressures. |
| NASCLA Contractor's Guide to Business, Law and Project Management, Mississippi | 6th Edition | Separate Mississippi Law and Business Management examination. |
Plumbing trade: Three approved references.
Business and Law: Separate Mississippi NASCLA guide.
Book rules: Highlighting, underlining, and compliant permanent indexing before the exam.
Not permitted: Temporary tabs, loose sheets, and unauthorized attachments.
Edition rule: The 2021 IPC is the exam's specifically listed code edition.
Open-book plumbing exams reward knowledge and efficient reference navigation.
The current Mississippi Plumbing examination allows 180 minutes for 70 scored questions.
That is approximately two minutes and 34 seconds per question on average.
Begin by identifying the subject of each question.
A code question about vent sizing should lead to the International Plumbing Code.
An excavation-safety question should lead to OSHA Part 1926.
A plumbing measurement or offset calculation may require Mathematics for Plumbers and Pipefitters.
Use compliant permanent tabs to make locating key reference areas easier.
Practice finding specific definitions, tables, and provisions without reading unrelated sections.
Always check the conditions and exceptions surrounding a code rule.
Mississippi's Plumbing specialty classification covers commercial and residential plumbing installation, maintenance, and repair.
Its stated scope includes sanitary drainage, storm drainage facilities, vents, public and private water supplies, septic systems, wells, swimming pool piping, and irrigation piping.
The classification definition also includes certain additional specialty piping and related systems.
Contractors must determine whether special permits, additional licensing, inspections, or agency approvals are required for particular work.
The PSI Plumbing trade exam does not include fuel-gas or boiler systems.
Do not interpret the trade examination's limited tested topics as permission to ignore other regulations affecting actual projects.
Mississippi also has a separate Residential Plumbing classification.
That license applies to its own residential scope and has a different examination.
MSBOC makes final determinations about classification boundaries.
Local building officials may require permits and inspections before plumbing work can begin or be concealed.
Contractors should check local adopted codes, water utility requirements, and applicable environmental or health regulations.
Plumbing classification: Commercial and residential plumbing specialty work.
Trade exam exclusion: Fuel-gas and boiler systems.
Residential Plumbing: Separate license classification.
Final scope authority: Mississippi State Board of Contractors.
| Classification | Authority | Main Difference |
|---|---|---|
| Plumbing | MSBOC | Specialty classification covering broad commercial and residential plumbing work. |
| Plumbing PSI Trade Exam | PSI | 70 scored questions, three hours, 70% passing, 2021 IPC. |
| Residential Plumbing | MSBOC | Separate residential-only plumbing classification. |
| Residential Plumbing PSI Exam | PSI | 80 questions, four hours, 70% passing, and a different exam blueprint. |
| Mechanical Contractor | MSBOC | Separate broader mechanical classification, including HVAC-related systems and associated work. |
| Mechanical PSI Exam | PSI | 100 questions, four hours, 70% passing, and broader mechanical and plumbing topics. |
| Water and Sewer Utility Work | MSBOC | May require a separate utility-related classification depending on project scope. |
| Mississippi Law and Business Management | PSI | 50-question contractor business exam normally required in addition to trade testing. |
Business and Eligibility
70 Questions and Three Approved Books
Separate Contractor Exam
Use this schedule to organize the 14 PSI Plumbing topics, approved books, calculation practice, and separate business-law preparation.
The Mississippi Plumbing Contractor examination can be challenging because it combines practical plumbing knowledge with code interpretation, construction safety, and mathematics.
It contains 70 scored questions and allows three hours.
Although it is an open-book examination, applicants still need to locate answers quickly.
Drain, Waste and Vent is the largest subject area.
Questions may involve fixture-unit loads, pipe sizes, slopes, vents, and drainage layouts.
Isometric Analysis is the next-largest category.
Applicants unfamiliar with three-dimensional plumbing drawings may need additional practice.
Together, these two topics account for approximately 38.6% of scored questions.
However, the exam also covers water supply, backflow protection, fixtures, valves, supports, traps, cleanouts, safety, and developed lengths.
These subjects require familiarity with the 2021 International Plumbing Code and its tables.
Construction-safety questions may require using OSHA Part 1926.
Mathematics problems may involve measurements, conversions, geometry, and pipe layout calculations.
The Mississippi Plumbing Contractor Book Package provides the three approved references.
The Mississippi PSI Plumbing Contractor Online Course supports additional structured review.
Use both knowledge and timed practice to develop better exam habits.
Understanding the plumbing concept before looking it up is often faster than searching blindly through a book.
Contractor Exam Preps offers matching plumbing reference books, an online trade examination course, and Mississippi Business and Law study materials.
All Three Approved Plumbing Trade References
Package note: Standard books only. Professional highlighting, tabbing, and online course access are not included.
Structured Online Trade Preparation
Package note: Physical reference books and licensing services are not included unless separately purchased.
Separate Contractor Business Examination
Trade books: Three-book Mississippi Plumbing Contractor package.
Digital preparation: Mississippi PSI Plumbing Contractor Online Course.
Business exam: Mississippi NASCLA Guide and PSI Business and Law Practice Questions.
Important: Match all reference editions to the current PSI bulletin.
Contractors preparing for multiple Mississippi license classifications can also browse the Mississippi Contractor Exam Prep Collection and the Mississippi Contractor Licensing Guide.
The book-package image is loaded from the matching ContractorExamPreps.com product listing. The accompanying Mississippi credential illustration is educational and is not an official state license.
This Mississippi-themed educational credential highlights the Plumbing specialty classification, plumbing systems, trade mathematics, PSI examination, and related licensing responsibilities.
The matching store product image is sourced from the Mississippi Plumbing Contractor Exam Book Package at ContractorExamPreps.com.
• Mississippi State Board of Contractors
• Plumbing Specialty Classification
• Mississippi PSI Examination
• 70 Scored Trade Questions
• 180-Minute Trade Examination
• 70% Passing Score
• 49 Correct Answers Required
• Open-Book Examination
• Three Approved Reference Books
• 2021 International Plumbing Code
• OSHA 29 CFR Part 1926
• Mathematics for Plumbers and Pipefitters
• General Plumbing Regulations
• Drain, Waste and Vent Systems
• Sanitary Drainage
• Vent Systems
• Drainage Pipe Sizing
• Fixture Units
• Plumbing Isometric Analysis
• Plumbing Diagrams
• Developed Pipe Lengths
• Plumbing Mathematics
• Pipe Offsets
• Water Supply
• Water Distribution
• Potable Water Systems
• Backflow Prevention
• Cross-Connection Control
• Plumbing Fixtures
• Water Heaters
• Plumbing Cleanouts
• Traps and Interceptors
• Piping and Valves
• Plumbing Controls
• Hangers and Supports
• Pipe Joints and Connections
• Plumbing Installation Requirements
• OSHA Construction Safety
• Excavation Safety
• Ladder and Scaffold Safety
• Personal Protective Equipment
• Codebook Navigation
• Compliant Permanent Reference Tabs
• Mississippi Qualifying Party
• Contractor Application
• MSBOC Exam Eligibility
• Mississippi Law and Business
• Business Organization
• Project Management
• Financial Management
• Construction Contracts
• Lien Law
• Annual License Renewal
• Contractor Exam Preps Study Books
• PSI Plumbing Online Preparation
Mississippi Plumbing Contractor Licensing
Mississippi identifies Plumbing as a specialty contractor classification regulated by the Mississippi State Board of Contractors.
The Mississippi State Board of Contractors, or MSBOC, administers the contractor licensing process.
The classification includes commercial and residential plumbing, water supplies, drainage, vents, fixtures, storm drainage, septic systems, and other specified plumbing work. MSBOC determines final classification scope.
No. Residential Plumbing is a separate Mississippi classification with a different examination and a residential-only scope.
Yes. MSBOC must review the application and establish examination eligibility before PSI scheduling.
The qualifying party is the person designated to satisfy examination requirements for the contracting business. The person must have an appropriate relationship with the applicant.
No. Passing the exams is one part of the licensing process. MSBOC must approve the completed application and all required documents.
Mississippi Plumbing PSI Trade Exam
The current Plumbing trade examination contains 70 scored questions.
The examination allows three hours, or 180 minutes.
A minimum score of 70%, or 49 correct scored answers out of 70, is required.
PSI administers the examination after the Mississippi State Board of Contractors approves the applicant's eligibility.
Yes. Candidates may bring the approved reference books while following the current PSI restrictions on book preparation and materials.
PSI may include a small number of unscored experimental questions in addition to the listed scored questions. They may count against the examination time.
Current guidance generally provides a six-month eligibility period for new applicants to complete required examinations.
Mississippi Plumbing Exam Topics
Drain, Waste and Vent is the largest category, with 15 scored questions.
The current PSI examination outline assigns 12 questions to Isometric Analysis.
Water Supply accounts for six questions.
Fixtures and Equipment accounts for five scored questions.
Yes. Four questions cover safety. OSHA Part 1926 is one of the three approved references.
No. The PSI Plumbing examination scope specifically excludes fuel-gas and boiler systems.
Yes. Drainage fixture units are important when sizing sanitary drainage piping and interpreting plumbing code tables.
Yes. Isometric drawings are a major exam topic, with 12 questions covering piping layouts and related analysis.
Yes. Developed Length is a separate category with two questions and also supports isometric drawing practice.
Reference Books and Open-Book Rules
The current PSI Plumbing trade reference list specifies the 2021 International Plumbing Code.
Three: the 2021 International Plumbing Code, OSHA 29 CFR Part 1926, and Mathematics for Plumbers and Pipefitters, 8th Edition.
Yes. PSI allows compliant permanent indexing before the examination. Review the current bulletin for exact conditions.
No. Temporary tabs and removable notes are not permitted in approved exam references.
Yes. PSI generally permits highlighting and underlining before testing, but writing inside references during the examination is prohibited.
The PSI bulletin permits a silent, nonprinting, nonprogrammable calculator. Confirm its current approval requirements before testing.
Mississippi Business and Law Examination
Yes. MSBOC requires the Law and Business Management examination for commercial and residential contractor applicants.
The examination contains 50 scored questions and allows 120 minutes.
A minimum score of 70% is required, meaning 35 correct scored answers out of 50.
The current approved reference is the Mississippi NASCLA Contractor's Guide to Business, Law and Project Management, 6th Edition.
Mississippi reciprocity may waive qualifying trade examinations, but the state still requires its contractor application and Business and Law examination.
Contractor License Maintenance
Mississippi contractor licenses are generally valid for one year and must be renewed annually.
Do not assume that a single statewide continuing-education requirement applies to every Plumbing Contractor classification. Verify the rule for your specific license with MSBOC.
Applicable local and state rules may require plumbing permits, inspections, and compliance with adopted plumbing codes. Check the authority having jurisdiction for each project.
Contractor Exam Preps Products
Yes. ContractorExamPreps.com offers a Mississippi Plumbing Contractor Exam Book Package with the three listed PSI trade references.
The package contains the 2021 IPC, OSHA 29 CFR Part 1926, and Mathematics for Plumbers and Pipefitters, 8th Edition.
No. The standard Mississippi Plumbing Contractor Book Package does not include professional highlighting and tabbing.
Yes. Contractor Exam Preps offers the Mississippi PSI Plumbing Contractor Online Course with one year of online access, practice-oriented study, and reference-navigation guidance.
No. Books are not included with the online course unless a separate purchased package specifically includes them.
Yes. The store offers Mississippi PSI Law and Business Management Online Practice Questions and the Mississippi NASCLA business reference.
No. Study materials support preparation, but examination performance and MSBOC approval depend on satisfying the state's requirements.
Watch this directly related 1ExamPrep video about the Mississippi Plumbing Contractor licensing process, PSI examination preparation, plumbing code study, reference books, safety, and open-book test strategies.
The video explains important preparation ideas for contractors pursuing Mississippi's Plumbing specialty classification.
Video title: How to Pass Mississippi Plumbing Contractor Exam.
Creator: 1ExamPrep.
Related subjects: Mississippi licensing, plumbing code preparation, approved books, PSI examination strategies, and contractor business responsibilities.
Current Plumbing trade exam: 70 scored questions, 180 minutes, 70% passing.
Reminder: The current PSI Candidate Information Bulletin controls examination rules.
Watch How to Pass Mississippi Plumbing Contractor Exam on YouTube
Use the Mississippi State Board of Contractors and PSI for official requirements. Explore Contractor Exam Preps for plumbing reference books, an online course, and business-law study materials.
Classification: Mississippi Plumbing Contractor.
Authority: MSBOC.
Testing: PSI.
Trade: 70 scored questions, three hours, 70% passing.
Approved trade books: 2021 IPC, OSHA 29 CFR Part 1926, and Mathematics for Plumbers and Pipefitters.
Law and Business: Separate 50-question examination.
Licensing: Board approval and annual renewal.
Preparing for the Mississippi Plumbing Contractor examination is an important step for professionals who want to operate a licensed plumbing contracting business.
The Mississippi State Board of Contractors regulates the Plumbing specialty classification.
This classification covers a wide range of commercial and residential plumbing work, including water supply, sanitary drainage, venting, storm drainage, and related systems.
Plumbing contractors help protect drinking water, safely remove wastewater, and keep buildings functioning properly.
The work requires an understanding of approved installation methods, plumbing materials, system sizing, testing, inspections, and construction safety.
Mississippi requires applicants to complete the contractor licensing process through MSBOC.
Applicants must choose the correct classification, submit the appropriate paperwork, designate a qualifying party, and meet the Board's application requirements.
Only after MSBOC approves examination eligibility can applicants schedule their PSI examinations.
The current Mississippi Plumbing trade examination contains 70 scored questions.
Candidates are given three hours to complete the test.
The passing score is 70%.
That means at least 49 correct scored answers are required.
The test is open book, but the rules governing approved references are important.
Candidates must bring the specific books listed by PSI.
Those include the 2021 International Plumbing Code, OSHA Part 1926, and Mathematics for Plumbers and Pipefitters, 8th Edition.
The approved books can be highlighted and permanently indexed before testing, subject to PSI restrictions.
Temporary tabs, loose notes, and unauthorized inserted materials are not allowed.
These rules make book preparation an important part of examination readiness.
Understanding plumbing concepts is essential, but so is knowing where to find supporting code provisions quickly.
The trade examination includes 14 subject categories.
Drain, Waste and Vent is the largest category, with 15 scored questions.
Isometric Analysis follows with 12 questions.
Together, these two areas represent approximately 38.6% of the examination.
That is a strong reason to spend additional study time reviewing drainage piping, venting requirements, fixture units, developed lengths, and plumbing diagrams.
Drainage questions may involve pipe size, slope, fixture-unit totals, horizontal branches, stacks, and building drains.
Venting questions may involve how plumbing vents connect to a drainage system and help protect fixture trap seals.
Isometric drawings require students to follow piping relationships in three dimensions.
Other important examination subjects include water supply, fixtures, general plumbing regulations, cleanouts, traps, interceptors, backflow protection, valves, hangers, supports, and joints.
Safety is also included.
OSHA construction safety helps protect workers from hazards such as unsafe trenches, falls, equipment injuries, and material-handling problems.
The plumbing mathematics reference supports measurement conversions, geometry, pipefitting offsets, and other calculations used during the examination.
Contractor Exam Preps offers the Mississippi Plumbing Contractor Exam Book Package.
This package contains the three approved trade references.
It is useful for contractors who want to organize their plumbing, construction safety, and mathematics study materials in one place.
The standard package contains the reference books without professional highlighting or tabbing.
That allows candidates to prepare the books according to their individual study preferences while following current PSI rules.
Contractor Exam Preps also offers the Mississippi PSI Plumbing Contractor Online Course.
The course provides structured instruction, test-taking guidance, reference-navigation strategies, and practice-oriented review.
Its one-year online access allows candidates to study around work schedules and other responsibilities.
Applicants should remember that the online course does not automatically include the physical reference books.
Those must be purchased separately unless a selected package specifically includes them.
The Mississippi licensing process also includes a separate Law and Business Management examination.
This test contains 50 scored questions and allows two hours.
Its passing score is 70%, or 35 correct scored answers.
The examination covers contractor licensing, estimating, bidding, contracts, lien law, financial management, tax obligations, employment requirements, project management, and risk management.
The Mississippi NASCLA Contractor's Guide, 6th Edition, is the approved reference for that examination.
Contractor Exam Preps sells the NASCLA business reference and Mississippi PSI Law and Business Management Online Practice Questions.
Preparing for the business examination matters because running a contractor business involves responsibilities beyond plumbing installation.
Contractors need to communicate with customers, organize projects, schedule work, manage finances, maintain insurance, and understand applicable laws.
A six-week study schedule can make preparation easier.
Begin by organizing the reference books and studying the official exam outline.
Use the second week for Drain, Waste and Vent.
Use the third week for Isometric Analysis and plumbing calculations.
Review water supply, fixtures, water heaters, and backflow during the fourth week.
Then study cleanouts, traps, pipe supports, joints, OSHA safety, and Business and Law.
During the final week, complete timed practice examinations.
Practice answering 70 scored questions within the 180-minute limit.
Review missed questions and repeat difficult code lookups.
Learn to identify which reference applies before opening a book.
This habit can reduce unnecessary searching and improve time management.
Applicants should also confirm that they are preparing for the correct Mississippi license classification.
Mississippi Plumbing and Residential Plumbing are separate classifications with different examination requirements.
The Plumbing trade examination covered in this guide specifically excludes fuel-gas and boiler systems.
After passing the required examinations, the contractor must still receive final MSBOC approval.
Once issued, Mississippi contractor licenses generally remain valid for one year and require annual renewal.
Contractors must continue following applicable insurance, permit, inspection, safety, business, and licensing obligations.
The purpose of Mississippi Plumbing Contractor exam preparation is not simply to memorize enough answers to pass a test.
It is to develop the technical knowledge and reference skills needed to plan, install, maintain, and evaluate plumbing systems responsibly.
With the correct PSI books, consistent plumbing mathematics practice, strong DWV and isometric skills, and related Contractor Exam Preps resources, applicants can approach the Mississippi Plumbing Contractor licensing examination with better preparation.
Find Mississippi Plumbing Contractor reference books, online exam preparation, plumbing-code resources, and contractor Business and Law materials at ContractorExamPreps.com.
