Maryland Master Plumber / Gas Fitter

Maryland Master Plumber / Gas Fitter Exam: Complete 2026 Study Guide

You've put in the hours. You've worked under a licensed master plumber, logged your time as a journey plumber, and completed your backflow prevention course. Now the Maryland Master Plumber / Gas Fitter exam stands between you and your license. This guide covers exactly what's on the test, what to bring, what to study, and how to walk in ready. Start with our free practice exam to see where you stand right now.

Exam Overview

The Maryland Master Plumber Gas Fitter exam is administered by PSI and consists of 100 scored questions. You have 240 minutes (4 hours) to complete it. Be aware that a small number of experimental items may also appear — these count against your time but are not scored. The passing score is 70%, meaning you need at least 70 correct answers on the scored questions.

This is an open-book exam. You may bring approved reference books: the International Plumbing Code (2018), the International Fuel Gas Code (2018), Mathematics for Plumbers and Pipefitters (Lee Smith, 8th Edition), a standard backflow text, and 29 CFR Part 1926 (OSHA). Study guides are not permitted. Books must be clean — no handwritten notes, no loose papers, no attached tabs with written labels.

The exam is offered at PSI testing centers. Check the official exam bulletin for center locations and scheduling details.

What Topics Are Covered

The exam spans ten topic areas. Here's how the real exam weights them — this is where your study time should go:

• Gas Appliances and Piping — 40 items (40% of the exam). This is the heaviest section by far. Gas piping materials, pipe sizing with capacity tables, pressure testing, combustion air, and venting systems.
• Drain, Waste, and Vent Systems — 13 items. DFU calculations, drain sizing, slope requirements, cleanout placement, and vent types.
• Water Supply Systems — 8 items. Pipe materials, joining methods, pressure regulation, flow rates, and valve requirements.
• Plumbing Mathematics — 7 items. Offset calculations, fitting allowances, unit conversions, volume and weight problems, pressure and head calculations.
• Backflow Prevention — 10 items. Device types and standards, hazard classification, cross-connection control, and specific application requirements.
• Materials, Uses, and Specifications — 6 items. Approved and prohibited piping materials, identification markings, and joining specifications.
• Plumbing Fundamentals and Safety — 5 items. IPC and IFGC scope, code administration, defined terms, OSHA responsibilities, and jobsite sanitation.
• Plumbing Fixtures, Fixture Fittings, and Plumbing Appliances — 4 items. Minimum fixture counts, installation clearances, fixture standards, and flushing devices.
• Traps, Interceptors, and Backwater Valves — 4 items. Trap distance limits, prohibited trap types, grease interceptors, and oil separators.
• Special Topics — 3 items. Storm drainage sizing, roof drains, subsoil drains, and nonpotable water systems.

Gas Appliances and Piping alone accounts for 40% of the test. Don't shortchange that section.

Sample Questions

Here are a few examples of what you'll see. Try to answer them yourself — then take our free practice exam to check your knowledge.

Question 1 — Plumbing Fixtures

What is the maximum percentage of required water closets that urinals may replace in an educational occupancy?

• A) 50 percent
• B) 67 percent
• C) 75 percent
• D) 25 percent

Question 2 — Plumbing Mathematics

A master plumber needs to determine the weight of water in a tank that has a capacity of 80 cubic feet. Using the standard weight of water per cubic foot, how many pounds of water does this tank hold when full?

• A) 5,000 pounds
• B) 4,000 pounds
• C) 5,500 pounds
• D) 6,000 pounds

Question 3 — Gas Appliances and Piping

What is the minimum burial depth for underground gas piping systems?

• A) 6 inches below grade
• B) 8 inches below grade
• C) 12 inches below grade
• D) 18 inches below grade

Question 4 — Gas Appliances and Piping

Which of the following is NOT an approved type of overpressure protection device for gas piping systems?

• A) Pressure relief valve
• B) Automatic shutoff device installed in series with the line pressure regulator
• C) Backflow preventer
• D) Monitoring regulator

Question 5 — Plumbing Fixtures

As a master plumber, you are installing a gas clothes dryer in a residential laundry room. Which of the following statements about the exhaust duct termination is correct?

• A) The exhaust duct must terminate on the outside of the building with a backdraft damper, and screens shall not be installed at the termination
• B) The exhaust duct may terminate in an attic space provided a lint trap is installed at the termination point
• C) A 1/4-inch mesh screen is required at the exterior termination to prevent pest entry
• D) The exhaust duct may connect to the building's vent or chimney system if the dryer input is below 30,000 Btu/h

Don't guess — know the answers cold before test day.

What Types of Questions to Expect

Our full practice pool contains 515 questions across all ten topic areas. Here's what each section tests and how many practice questions we offer:

• Plumbing Fundamentals and Safety (27 practice questions): IPC/IFGC scope, code administration, permit requirements, OSHA employer responsibilities, and jobsite sanitation rules.
• Materials, Uses, and Specifications (29 practice questions): Identifying approved vs. prohibited materials, reading pipe markings, and selecting the right fitting type for each joint method.
• Traps, Interceptors, and Backwater Valves (20 practice questions): Trap distance limits from fixture to trap, prohibited trap configurations, seal depth requirements, and grease interceptor sizing.
• Plumbing Fixtures, Fixture Fittings, and Plumbing Appliances (20 practice questions): Minimum fixture counts from Table 403.1, installation clearances, fixture standards, and flushing device requirements.
• Water Supply Systems (40 practice questions): Matching pipe materials to joining methods, sizing fixture supply pipes, pressure regulation, and valve placement rules.
• Backflow Prevention (43 practice questions): Selecting the right backflow device for a given hazard level, cross-connection restrictions, and installation requirements by application.
• Drain, Waste, and Vent Systems (61 practice questions): DFU value assignments, drain and branch sizing, minimum slope, cleanout spacing, and vent sizing and developed length.
• Special Topics (14 practice questions): Storm drainage sizing based on rainfall rates, roof drain installation, secondary overflow systems, and nonpotable water system requirements.
• Gas Appliances and Piping (162 practice questions): Approved gas piping materials, pipe sizing from capacity tables for natural gas and LP-gas, pressure testing procedures, combustion air calculations, and venting system selection and termination.
• Plumbing Mathematics (99 practice questions): Offset calculations at 45°, 60°, and 22½° angles; fitting allowances by material; volume and weight problems; and pressure and head conversions.

Study Materials

This exam is open book, so having the right references with you matters. These are the materials you need:

Required References:

• 2018 International Fuel Gas Code (IFGC) — Gas Appliances and Piping alone covers 40 items on this exam. Know this code cold. Tabs help you find sections fast under time pressure.
• OSHA 29 CFR 1926 — Standards for the Construction Industry — Tested on Fundamentals and Safety. Not a huge section, but the questions are straightforward if you've read it.

Study Tools:

• Sharpie Tank Highlighters — Fluorescent ink that resists smearing. Use multiple colors to code different code sections. The wide barrel holds up through heavy use. Pack includes 12 highlighters in assorted colors.
• Redi-Tag Permanent White Tabs — 375 laser tabs per pack. Create a clean index in your code books so you can flip straight to combustion air tables, pipe sizing charts, or venting requirements without burning time. Strong adhesive keeps them in place.

Remember: books must be free of handwriting. Use tabs and highlights, not written notes.

Study Tips That Actually Help

Simulate real test conditions. Our full practice exam matches the real exam format — same number of questions, same time limit, same topic breakdown. A PDF study guide gives you the material but doesn't prepare you for the clock. Practice under pressure.

Trust your preparation on unfamiliar answer choices. If you've genuinely studied and an option looks completely foreign, it's probably a distractor. A choice you don't recognize at all is rarely the right answer.

Manage the clock without watching it obsessively. 240 minutes for 100 questions is 2.4 minutes per question — that's workable. Set a pace and check yourself at regular intervals. If you're at question 50 with 120 minutes left, you're on track. Don't let the final stretch feel like a crisis if you're exactly where you should be.

Front-load your gas code prep. With 40 out of 100 exam items on Gas Appliances and Piping, that section alone determines whether you pass or fail. Pipe sizing tables, combustion air, and venting terminations are all fair game — know them well.

Use the PSI Maryland Master Plumber and Gas prep exam format. The official exam bulletin outlines topic weights. Our practice exam is built around those same weights.

FAQs

How much does the Maryland Master Plumber/Gas Fitter exam cost?
The exam fee is $65. That fee covers one attempt only — it's non-refundable and non-transferable. If you need to retake, you pay another $65, which is valid for one year.

How many questions are on the exam and how long do I have?
The exam has 100 scored questions. You have 240 minutes (4 hours). A small number of experimental items may also appear — they count against your time but are not scored.

What is the passing score?
You need 70% — that's 70 correct answers out of 100 scored questions.

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

What experience do I need to qualify?
For Maryland residents or applicants with Maryland work experience: at least two years of approved experience under a licensed Maryland Master Plumber, including 3,750 working hours as a licensed Maryland Journey Plumber, plus a completed non-expired 32-hour Backflow Prevention Device Testing course. Different documentation requirements apply if your experience was outside Maryland — check the official exam bulletin for the full breakdown.

Is the exam open book?
Yes. You may bring the IPC (2018), IFGC (2018), Mathematics for Plumbers and Pipefitters (Lee Smith, 8th Edition), a standard backflow text, and 29 CFR Part 1926. No study guides. Books must have no handwriting and no loose or attached papers.

What ID do I need?
One valid, non-expired, signature-bearing government-issued photo ID. Driver's license, state ID, US passport, military ID, alien registration card, or Canadian government ID all work. The name must match your registration exactly.

Can I bring a calculator?
No. All electronic devices are prohibited. You'll do the math by hand — which is exactly why practicing those offset and volume calculations matters.

What happens if I fail?
You'll receive a score report showing which areas you missed. You also get 30 minutes right after the exam to review missed items at no charge. Then pay a new $65 fee and reschedule.

Can I reschedule?
Yes, if you give at least 48 hours' notice before your scheduled time. Cancel via the PSI website or by speaking directly with a PSI rep — voicemail and email don't count. Miss the window and you forfeit your fee.

Ready to Start?

You've already done the hard part — years of hands-on work, your journey license, your backflow course. The exam is one more step. Study the gas code hard, work through your math calculations until they're automatic, and practice under timed conditions.

Start with our free practice exam — 10 questions, no account needed, no cost. See where you stand. Then move to the full practice exam when you're ready to train at real exam difficulty and duration. The state licensing website has additional licensing information if you need it. Go earn that master's license.