How to Pass the Mississippi Mechanical Contractor Exam
You don't have to guess how to prepare for the Mississippi Mechanical Contractor exam. This guide lays it out: the key facts from the official bulletin, the topics on the test, the books you need, sample questions with answers, and a study plan you can follow. PSI gives the exam.
Mississippi Mechanical Contractor Exam Basics
Here's what the official bulletin says about the exam:
| Questions | 100 questions |
| Time limit | 4 hours |
| Passing score | 70% correct |
| Books in the exam room | Open book |
| Exam fee | The examination fee is $120 for one examination portion and $240 for two examination portions, charged for each registration whether it is a first attempt or a retake. |
On exam day
- You must bring one valid, unexpired identification bearing your signature and photograph whose name matches your registration.
- Arrive at the examination site at least 30 minutes before your appointment.
- Candidates bring their own approved references, which may not be written in and may not contain any additional loose or attached papers.
- Highlighting, underlining and indexing done before the exam are allowed, writing in the book is not, and only permanent tabs may be used.
- A silent, battery-operated, nonprinting, non-programmable calculator without an alphabet keyboard may be used.
- Personal items, including electronic devices, reading material and writing devices, must be left in secure storage outside the examination room.
References you may bring
- Modern Refrigeration and Air Conditioning, Althouse, Turnquist, Bracciano (20th, 21st, or 22nd edition (Starting 8/1/2026 the 20th and 21st editions will no longer be used))
- Code of Federal Regulations - 29 CFR Part 1926 (OSHA), with latest available amendments
- Code of Federal Regulations - 29 CFR Part 1926 Selections by PSI, with latest available amendments
- International Fuel Gas Code (2021)
- HVAC Duct Construction Standards, Metal and Flexible (2005, 3rd edition)
- Manual N - Load Calculation for Small Commercial Buildings (Fifth Edition, 2008)
- International Mechanical Code (2021)
- International Plumbing Code (2021)
- NFPA 58 Liquefied Petroleum Gas Code (2020 Edition, 2001)
- NFPA 13: Installation of Sprinkler Systems (2019)
- ACCA Ductulator
- Manual D (2016 4th Ed)
- Pipefitters Handbook (3rd Edition, 1967)
Scheduling, changes and retakes
- You schedule your examination online at https://test-takers.psiexams.com/mscontlb or by calling PSI at (855) 557-0619.
- The Board must find you eligible and notify PSI before you test, and eligibility lasts 6 months from the date of eligibility.
- Fees are never refunded, but you may cancel and reschedule without forfeiting your fee if PSI receives notice 2 days before the exam date, and unused funds are held for one year from the initial registration date.
- Missing the appointment, arriving after the start time, cancelling late, or not presenting proper ID forfeits your registration and fee, and you must re-register.
- Results are given immediately on screen, with a performance summary for passers and a diagnostic report of strengths and weaknesses for those who fail.
- You may retest an unlimited number of times during your 6-month eligibility period, paying the fee each time.
- After passing and meeting all licensing requirements, the Board reviews complete applications weekly and successful candidates receive their Certificate of Responsibility or Residential License about one week after Board approval.
Source: State of Mississippi Contractor Examinations Candidate Information Bulletin, Updated 4/23/2026. Check the bulletin before test day: fees and rules can change.
What's on the Mississippi Mechanical Contractor Exam
The official content outline splits the exam into 23 topics:
| Topic | Questions | Share of the exam |
|---|---|---|
| Boilers and Hydronics | 6 | 6% |
| Gas Systems | 10 | 10% |
| Cleanouts | 3 | 3% |
| Plumbing Fixtures and Equipment | 5 | 5% |
| Water Heaters | 2 | 2% |
| Piping, valves, controls | 5 | 5% |
| Sheet Metal and Ducts | 6 | 6% |
| Water Supply | 5 | 5% |
| Hangers and Supports | 4 | 4% |
| Drain, Waste, and Vent | 5 | 5% |
| Backflow | 2 | 2% |
| Traps and Interceptors | 4 | 4% |
| Developed length | 3 | 3% |
| Isometric Analysis | 8 | 8% |
| Safety | 4 | 4% |
| Joints and Connections | 3 | 3% |
| General Plumbing Regulations | 3 | 3% |
| Fire Sprinklers | 4 | 4% |
| Refrigerants and Refrigeration | 4 | 4% |
| Heating and Cooling Principles | 4 | 4% |
| Load Calculations | 5 | 5% |
| Testing, Adjusting and Balancing | 1 | 1% |
| HVAC Equipment | 4 | 4% |
Your Mississippi Mechanical Contractor Study Plan
Your books are your best friend on this exam. It's open book, so the references on the bulletin's list are what you'll use on test day. Get your own copies in the editions the bulletin names.
Get to know them early. Spend time with each book's table of contents and index until you can find any major subject quickly. On an open-book exam, finding answers fast is the skill that counts.
Make the books yours. Highlight the sections you keep coming back to. The exam facts above list the bulletin's rules on tabs and markings, so follow them exactly.
Put your energy where the points are. Gas Systems and Isometric Analysis make up 18% of the exam, so start there.
Practice with the clock running. Our timed practice exams help you build the pace the real exam needs: about 2 minutes 24 seconds per question. Every attempt is another rep.
Keep going until you pass practice exams consistently. One good score is a great start. A few passing scores in a row is how you know you're ready.
Books You'll Need for the Mississippi Mechanical Contractor Exam
The Mechanical Contractor reference list names the materials allowed in the examination center, beginning with Modern Refrigeration and Air Conditioning.
Where to get them:
- IFGC 2021
- IMC 2021
- IPC 2021
- OSHA 29 CFR 1926
- HVAC Duct Construction Standards
- Manual N - Load Calculation for Small Commercial Buildings
- NFPA 13: Installation of Sprinkler Systems
- Pipefitter's Handbook
- NFPA 58 2020
- ACCA Manual D 3rd
- MR&AC 22nd
Test Day Tips
Start with a quick pass through the whole exam. Answer every question you're sure about and bookmark the rest. Every exam lets you return to bookmarked questions, so nothing is lost by moving on.
Then come back to your bookmarks and work through them one at a time. Keep an eye on the clock: you have 4 hours for 100 questions, which is about 2 minutes 24 seconds per question. Before you finish, make sure every question has an answer. A blank can't earn a point.
Study Tips
On an open-book exam, the winners aren't the smartest people in the room — they're the fastest at finding answers. Buy the required book, practice with it open, and tab and highlight each section the first time a question sends you there. Learn the index and table of contents until you can land on any topic in seconds. That speed is what separates a pass from a fail.
On an open-book exam, work through every question once: answer the ones you know and skip the ones you don't. Then go back to the ones you flagged. You can bookmark questions for later review, just like on our exams — and don't sink too much time into any single question. The clock is still running.
Give yourself at least three to six weeks. Use your exam's candidate bulletin as your roadmap for what's tested, and spend your time on finding-it-fast skills over rote memorization. In practice, aim for three clean passes at 80% or higher — setting your practice bar above the real cut score gives you a comfortable margin on test day.
Practicing against a ticking clock is the best way to beat exam-clock anxiety. Use these timed tests to build your pacing, so you learn to move steadily and never burn too long on a single question. By test day, the format feels routine.
Our practice exam is specifically designed to mimic the testing conditions at all exam centers. While untimed PDF study guides might help with studying, they don’t prepare you for the challenge of managing your time during an actual test.
Know your way around each book's index and table of contents. Open-book exams reward speed: you need to find specific items quickly.
Try These Mississippi Mechanical Contractor Practice Questions
Give these a try. They come from our practice question bank, each with its answer and reference.
Sample 1 — Sheet Metal and Ducts
Question: Horizontal rigid rectangular metal duct must be supported to maintain alignment. In addition to the normal hanger spacing, a support is required within what distance of each branch intersection?
- A. 4 ft (1.2 m)
- B. 3 ft (0.91 m)
- C. 6 ft (1.8 m)
- D. 2 ft (0.61 m)
Correct Answer: A
Per SMACNA HVAC Duct Construction Standards, S4.0 (Hanging and Supporting Systems), horizontal ducts shall have a support within 2 ft (0.61 m) of each elbow and within 4 ft (1.2 m) of each branch intersection.
Reference: SMACNA HVAC Duct Construction Standards (3rd ed.), Page 5.1 (Section 5.1.1, S4.0)
Sample 2 — Plumbing Fixtures and Equipment
Question: A combination temperature and pressure relief valve serving a storage water heater must bear the label of an approved agency and have a temperature setting of not more than:
- A. 210°F
- B. 180°F
- C. 160°F
- D. 200°F
Correct Answer: A
IPC 504.5 requires temperature and pressure relief valves to have a temperature setting of not more than 210°F (99°C) and a pressure setting not exceeding the manufacturer's rated working pressure or 150 psi, whichever is less.
Reference: IPC 2021 Section 504.5
Sample 3 — Piping, valves, controls
Question: In a zoned hydronic heating system using a mercury switch thermostat to control a motorized zone valve, what must a journeyman technician verify about the thermostat mounting to ensure proper operation?
- A. That the thermostat is mounted at least 5 feet above the floor
- B. That the thermostat subbase is secured to a metal junction box
- C. That the thermostat is mounted on an exterior wall for accurate readings
- D. That the thermostat is mounted level, since tilt affects mercury switch calibration
Correct Answer: D
If a thermostat with a mercury switch is mounted at an angle, its set point calibration can be off. On every service call, a technician should check that a thermostat is mounted level, as this will affect the temperature at which the mercury flows from one end of the tube to the other, which directly affects zone valve operation.
Reference: Modern Refrigeration and Air Conditioning (22nd ed.), Chapter 17 - Electrical Control Systems, Page 328 (20th ed.: Pages 944–945)
Sample 4 — Water Supply
Question: What is the minimum diameter required for a water service pipe?
- A. 1 1/4 inches
- B. 1/2 inch
- C. 1 inch
- D. 3/4 inch
Correct Answer: D
Per IPC Section 603.1, the water service pipe shall be not less than 3/4 inch (19.1 mm) in diameter. This is the minimum size required to supply water to the structure in the quantities and at the pressures required by the code.
Reference: IPC 2021 Section 603.1
Why Practice Online?
Reading questions in a PDF is a start, but it doesn't prepare you for the clock. Our practice exams are timed and on a screen, so you build speed along with knowledge. Each attempt draws a new set of questions from our bank, and your results show your score by topic so you know where to focus next.
Ready to Start?
Take the free Mississippi Mechanical Contractor practice exam and see where you stand today. Then focus on the topics that need the most work. For the official rules, read the exam bulletin, and see the licensing board's website.