Maryland Master Natural Gas Fitter

Maryland Master Natural Gas Fitter Exam: Complete 2026 Study Guide

You've put in the hours as a journeyman natural gas fitter. Now it's time to make it official. Passing the Maryland Master Natural Gas Fitter exam opens the door to running your own jobs, pulling permits, and taking your career to the next level. But this is a 40-question, open-book exam with a 70% passing requirement — and "open book" doesn't mean easy. You still need to know where to look and how to work the problems quickly. This guide covers everything: what's on the exam, how to study, what to bring, and how to register.

Maryland Master Natural Gas Fitter Exam Overview

The exam is administered by PSI and consists of 40 scored questions with a 90-minute time limit. To pass, you need to answer at least 28 questions correctly — that's the 70% minimum passing score.

This is an open-book exam, which is good news. You can bring your reference books and even have them tabbed and highlighted. What you can't bring: study guides, loose papers, or books with handwritten notes. More on allowed materials below.

The exam is computer-based at a PSI test center. You'll get your score immediately after finishing — no waiting around for results. If you pass, you walk out with a successful score report. If you don't, you'll receive a failure report with instructions on how to apply for a retake.

For official exam details and to verify current requirements, check the official exam bulletin.

Topics Covered on the Maryland Natural Gas Fitter Exam

The exam is built around five topic areas. Here's how they break down by number of questions — and where you should focus your prep time:

General Piping — 15 questions (heaviest-weighted topic)
This is the largest section. Expect questions on approved piping materials (steel, copper, CSST, polyethylene), joint and fitting standards, installation requirements including burial depth and physical protection, and pressure testing and purging procedures. Know your allowable pressure drops and maximum operating pressures cold.

Pipe Sizing/Math — 10 questions
The second-biggest section and the one that trips up the most candidates. You'll work through gas pipe sizing using the longest-length and branch-length methods, pressure drop calculations, BTU/h-to-CFH conversions, and equivalent pipe length for fittings. Calculator skills and table-reading speed matter here.

Chimney and Flues — 5 questions
Covers vent types (Type B, BW, L, single-wall, direct-vent), appliance categories (I–IV), termination location rules, vent connector materials and slope, and masonry chimney requirements.

Combustion — 5 questions
Expect questions on combustion air requirements (the standard method: 50 cu ft per 1,000 Btu/h), opening sizing and placement for one- and two-opening methods, and mechanical supply systems.

Appliances — 5 questions
Listing and labeling standards, installation clearances for heaters and furnaces, unvented room heater rules, dryer exhaust requirements, and cooking appliance restrictions.

Sample Maryland Natural Gas Fitter Exam Prep Questions

Here are five questions similar to what you'll see on the real exam. Think through each one — but don't expect any answers here. That's what the free practice exam is for.

Question 1 — Pipe Sizing/Math
For a 45° parallel offset, the difference in pipe length between two parallel assemblies equals ______ × the spread (center-to-center distance between the two parallel pipe runs).
- A) 0.707
- B) 1.414
- C) 0.414
- D) 0.577

What it tests: Your ability to apply pipe offset geometry — the kind of calculation you'll find in your math reference book if you know where to look.

Question 2 — Chimney and Flues
A gas vent terminates on a rooftop near a building's forced-air intake. What is the minimum height the gas vent must terminate above a forced-air inlet located within 10 feet of the vent?
- A) 4 feet
- B) 3 feet
- C) 2 feet
- D) 5 feet

What it tests: Code-specific termination clearances from the IFGC — a straight table lookup if your book is well-tabbed.

Question 3 — Combustion
You are investigating a reported gas odor in a commercial kitchen. A gas detector reads a natural gas concentration of 3 percent in the air. Based on the flammable limits of natural gas, which of the following is correct?
- A) The mixture is within the flammable range and could ignite immediately
- B) The mixture is below the lower flammable limit and will not ignite, but the space must be ventilated to prevent reaching the 5 percent threshold
- C) The mixture is above the upper flammable limit and is too rich to ignite
- D) The mixture is at the ideal stoichiometric ratio for combustion

What it tests: Applied combustion theory — understanding flammable limits of natural gas in a real-world scenario.

Question 4 — Pipe Sizing/Math
You are surveying elevations on a gas piping project. The engineer's plan shows a fitting at elevation 96.38 feet. When converting this to builder's measure (feet, inches, and fractions), what is the equivalent measurement?
- A) 96 feet 4½ inches
- B) 96 feet 3⅞ inches
- C) 96 feet 4⅜ inches
- D) 96 feet 4⅝ inches

What it tests: Decimal-to-fractional conversion — a core skill covered in your math reference.

Question 5 — General Piping
According to the fuel gas code definitions, "tubing" is classified as a semirigid conduit and may be made of copper, copper-alloy, aluminum, plastic, or which other material?
- A) Steel
- B) Cast iron
- C) Brass
- D) Galvanized iron

What it tests: Definitions straight from the IFGC — easy points if you've read the definitions section.

Not sure on a few of these? Try our free practice exam to get a feel for the format before you sit for the real thing.

What Types of Questions to Expect (by Topic)

Here's a breakdown of what our practice question bank covers — and what skills each area actually tests:

General Piping — 75 practice questions
This is the largest topic on both the real exam and our practice bank. Questions cover material approvals, fitting and thread specifications, prohibited installation locations, burial depth rules, pressure testing procedures, and purging. Expect a mix of code lookups and scenario-based installation questions.

Pipe Sizing/Math — 44 practice questions
These problems require actual calculation: converting BTU/h to CFH, sizing pipe using code tables, computing equivalent lengths for fittings, and working through pressure drop scenarios. You'll also see decimal-to-fraction conversions and offset geometry.

Chimney and Flues — 25 practice questions
Questions here test your knowledge of vent system types, appliance categories, termination clearances, vent connector slope and material requirements, and masonry chimney code details.

Combustion — 25 practice questions
Expect scenario-based questions about combustion air volumes, opening sizing calculations using the standard method, and mechanical supply system requirements including appliance interlock rules.

Appliances — 25 practice questions
These cover installation clearances, listing requirements, unvented heater restrictions, dryer duct length limits, and cooking appliance placement rules.

In total, we offer 194 practice questions across all five topic areas. Start free, then upgrade to the full practice exam for the complete timed experience that mirrors the real thing.

Required Study Materials for the Maryland Natural Gas Fitter Exam

Since this is an open-book exam, your reference books ARE your tools — not just study aids. PSI specifies exactly which books are allowed. You need to own them and bring them to the test center.

2018 International Fuel Gas Code (IFGC) — This is your primary code reference and the source of most exam questions. Tab it thoroughly: definitions, pipe sizing tables, venting tables, combustion air sections, and appliance requirements. Know how the tables are organized before test day.

Mathematics for Plumbers and Pipefitters (8th Edition) — Required for the pipe sizing and math section. This book covers decimal conversions, offset calculations, equivalent lengths, and everything you'll need for the 10 math questions on the exam. Practice navigating it quickly — you don't want to be hunting for formulas under time pressure.

The third allowed reference is The Pipe Fitters and Pipe Welders Handbook (Revised Edition) by Thomas Frankland. All three books must be brought by you — PSI does not provide references at the test center.

Study Tips for the PSI Maryland Gas Fitter Practice Test and Beyond

Give yourself three to six weeks. Use the official exam bulletin as your roadmap, and focus your energy on learning your books — not memorizing answers. On test day, speed of reference is everything.

Set your practice bar at 80%. The real passing score is 70%, but if you're consistently hitting 80% or higher in practice, you'll have a solid cushion. Aim for three clean passes at that level before you schedule.

Rank your study time by exam weight. General Piping (15 questions) and Pipe Sizing/Math (10 questions) together make up more than half the exam. Put your heaviest prep there. The remaining three topics split the other 15 questions equally — don't ignore them, but don't let them crowd out the big two.

Manage exam anxiety like a pro. A little nervousness is normal and can actually sharpen your focus. If you feel stuck on a question, take a few slow breaths and reset. Don't spiral — flag the question and move on. The clock keeps running.

Work through the exam in two passes. Answer every question you're confident about first, flag the ones you're unsure of, then go back. Don't burn five minutes on one hard question when you could be banking points on ten easier ones.

Frequently Asked Questions

How many questions are on the Maryland Master Natural Gas Fitter exam, and how long do I have?
The exam has 40 questions and a 90-minute time limit. That's about 2 minutes and 15 seconds per question — tight but manageable if you're not hunting through unorganized books.

What is the passing score?
You need 70% — that's 28 correct out of 40. There's no partial credit, so every question matters.

What is the exam fee?
The examination fee is $65. It's non-refundable, non-transferable, and valid for one attempt only. Pay attention to that cancellation window if your plans change.

What are the eligibility requirements?
You must hold a current Maryland HVACR master or master restricted heating license in good standing, plus two years of work experience as a licensed journeyman natural gas fitter — working under a licensed master plumber, master gas fitter, or qualifying master/master restricted heating license holder.

How do I register?
Apply through the exam registration page and upload your documentation. PSI typically takes up to one week to process applications. Once approved, you'll get an email with instructions to pay and schedule online or by calling PSI at (855) 746-8173.

Is the exam open book?
Yes. You may bring your reference books tabbed and highlighted. Books cannot have handwritten notes or loose/attached papers, and study guides are not permitted.

What references can I bring?
Only three books are allowed: the 2018 IFGC, Mathematics for Plumbers and Pipefitters (8th Edition), and The Pipe Fitters and Pipe Welders Handbook by Thomas Frankland. Bring your own — PSI does not provide them.

What ID do I need?
One valid, non-expired, government-issued photo ID with your signature. A driver's license, state ID, US passport, military ID, Alien Registration Card, or Canadian government-issued ID all qualify.

Can I reschedule?
Yes — cancel or reschedule at least 48 hours before your appointment and your fee stays intact. The cancellation must go through the PSI website or a live PSI Customer Service Representative. Voicemail and email don't count.

When do I get my results?
Immediately after you complete the exam. You'll receive either a passing score report or a failing one with retake instructions — right there at the test center.

For the most current requirements and licensing information, visit the state licensing website.

Ready to Start Your Maryland Natural Gas Fitter Exam Prep?

You've got the experience. Now it's about translating that field knowledge into exam performance. Get familiar with the question style, sharpen your book navigation, and hit your practice sessions hard over the next few weeks.

Start with our free practice exam — no account required, no payment, just 10 questions to get a real feel for what you're facing. When you're ready to go deeper, upgrade to the full practice exam: same 40-question format, same time limit, detailed scoring by topic, and a large question pool so each attempt stays fresh.

You've done the work in the field. Let's make sure that shows up on your score report.