Journeyman Plumber Practice Test: Can You Pass These Code Questions?

The Uniform Plumbing Code family of journeyman exams is written board by board, and each board publishes its own format, code edition and passing score — so the first questions to pass are the ones about your own exam.

Work through these seven, then drill the code tables in the edition your board names.

If you have not yet confirmed what your state requires before you can sit the exam at all, start with our plumbing license requirements guide, then come back to practice.

Question 1: What is on New Mexico's journeyman written exam?

Answer: 70 questions in 185 minutes, and you need 75% — 53 points — to pass, per the state's PSI content outline (2023 bulletin).

The blueprint: drainage, waste and vents 21 of the 70; general knowledge and regulations 10; fixtures including water heaters 8; water supply 6; backflow 6; storm drainage 6; isometric analysis 5; interceptors and traps 4; septic and sewer 4.

Question 2: Which code books does New Mexico's exam use?

Answer: The 2023 PSI bulletin lists the 2021 Uniform Plumbing Code (IAPMO) and the New Mexico Plumbing Code (NMAC 14.8.2, 2015 edition).

State plumbing codes get revised — confirm the current reference list with the board before you buy a book.

Question 3: Which of these journeyman exams is closed book — Washington's or Alaska's?

Answer: Washington's.

Its plumber exams are administered by PSI on the 2015 Uniform Plumbing Code with Washington amendments, and the journey-level and residential exams are closed book.

Alaska's Plumber Journeyman exam is open book on the 2018 Uniform Plumbing Code, and its plumbing COF exams require 70% to pass, with a 30-day wait after a failed attempt.

Question 4: Describe Montana's journeyman written exam.

Answer: 100 multiple-choice questions on the 2021 Uniform Plumbing Code (as amended) plus board statutes and rules — open book, with a 3-hour limit.

A separate practical adds three virtual diagrams, limited to 2.5 hours.

Question 5: How does the NBOPE journeyman exam split its two parts?

Answer: Part one is 50 open-book questions in 2 hours; part two is 100 closed-book sizing questions in 2 more hours.

The exam is based on the currently adopted Uniform Plumbing Code, and you need 75% or 113 cumulative points to pass.

Question 6: What is Oregon's journeyman plumber exam format?

Answer: A 4-hour, 64-question open-book exam, per the Oregon Building Codes Division.

Question 7: True or false — an open-book exam means you can look up every answer during the test.

Answer: False.

ICC's own candidate bulletin warns that because of the time constraints, you will not have time to look up all of the answers — you have to know your references well.

The same bulletin notes there is no guessing penalty, so it is to your advantage to answer every question.

The International Plumbing Code family is the second branch of the map.

Indiana's journeyman plumber exam runs 90 questions in 3 hours — vents 17 of the 90, sanitary drainage 15, water supply and distribution 14, fixtures 10, developed length/isometric analysis 8, general requirements 7, water heaters 7, storm water 6, Indiana business 6 — at a $75 exam fee, per the May 2026 Prov bulletin.

Philadelphia's journeyman exam is 75 questions, closed book, 3 hours and $115, on the 2018 Philadelphia Plumbing Code, with plan reading and analysis worth 25% of the exam, drainage 15% and venting 15%.

The three questions below are worked from the 2024 International Plumbing Code, whose tables are published and citable.

Work each one before reading on — then check the answer against the table it names, because that habit, not memory, is what the questions test.

Question 8: Under the 2024 IPC, what is the minimum slope for a 4-inch horizontal drainage branch?

Answer: 1/8 inch per foot.

Table 704.1 sets 1/4 inch per foot for pipe 2-1/2 inches or smaller, 1/8 inch per foot for 3- to 6-inch pipe, and 1/16 inch per foot for 8-inch and larger.

The classic wrong answer is "1/4 inch per foot" — it is the minimum only for the small sizes.

Question 9: Your line drains to a grease interceptor. What slope does the 2024 IPC require upstream of it?

Answer: At least 1/4 inch per foot — a 2 percent slope — regardless of the pipe's size.

Upstream of an interceptor, the flatter minimums larger pipe otherwise gets do not apply.

Question 10: A plan sheet calls for 8-inch horizontal drainage. What is its minimum slope?

Answer: 1/16 inch per foot — Table 704.1's row for 8-inch and larger.

Reading the row for the size in front of you is the whole skill: the same table that lets a 2-inch line fall 1/4 inch per foot asks for far less fall on the big pipe.

One more trap worth naming: editions differ.

Indiana's plumbing exams still reference the 2006 International Plumbing Code (Indiana edition) with 2012 Indiana amendments, per the May 2026 Prov bulletin — so a practice answer keyed to the 2021 or 2024 IPC may not match the answer keyed to Indiana's exam.

Prov sells practice exams for $25 each if you want questions built to its bulletin; the free alternative is to re-derive every answer from the edition your board names.

Sizing is where closed-book exams earn their reputation: the NBOPE exam devotes its entire 100-question second part to sizing, closed book, and the blueprints weight it elsewhere too — New Mexico gives isometric analysis 5 of its 70 questions, Indiana gives developed length/isometric analysis 8 of 90.

Work these four from the 2024 IPC's tables.

Question 11: How many drainage fixture units is a lavatory, and what minimum trap size does the 2024 IPC assign it?

Answer: 1 DFU on a 1-1/4-inch minimum trap, per Table 709.1.

Question 12: And a residential bathroom group with a 1.6-gpf water closet?

Answer: 5 DFU.

The same table lists a bathtub at 2 DFU (1-1/2-inch minimum trap), a domestic kitchen sink at 2 DFU (1-1/2-inch), a residential clothes washer at 2 DFU (2-inch) and a private 1.6-gpf water closet at 3 DFU.

Question 13: How far can a 2-inch fixture trap sit from its vent?

Answer: 8 feet at 1/4 inch per foot of slope, per Table 909.1.

The ladder runs 5 feet for a 1-1/4-inch trap, 6 feet for 1-1/2-inch, 8 feet for 2-inch, 12 feet for 3-inch and 16 feet for 4-inch — the two larger sizes at 1/8 inch per foot — and self-siphoning fixtures such as water closets are not limited.

Question 14: A 45-degree offset rises 12 feet. How much pipe does the travel consume?

Answer: Multiply the offset by the 45-degree multiplier, 1.414: 12 x 1.414 = 16.97 feet of pipe.

The offset multipliers are 1.414 for 45 degrees, 2.000 for 30, 1.155 for 60, 2.613 for 22-1/2 and 5.126 for 11-1/4.

Score the set honestly: 14 questions, marked answer by answer.

Then put every miss into a bucket — slope, fixture units, trap-arm distances, offsets — and weight the buckets the way your board does.

New Mexico counts drainage, waste and vents at 21 of its 70 questions, so a miss in that bucket costs more study time than a storm-drainage one (6 questions); Indiana counts vents at 17 and sanitary drainage at 15 of its 90.

Know which style you are walking into, too: formats run from fully open book to fully closed.

New York City's master plumber written exam — the step above journeyman — is multiple-choice on the NYC Construction Codes with no reference materials permitted, needs 70% to pass and costs $585, and its $530 practical must be passed within 24 months of the written-exam notification.

For the exam's full anatomy — practical portions, isometric drawing, pass scores and retake waits — read our guide to the journeyman plumber test, and for the supervised hours and application that get you a seat, see the journeyman plumber license guide.

When you have passed, put the license to work: browse plumber jobs to see what contractors are hiring journeymen for right now.

Career information, not legal advice. Exam formats, code editions, fees and passing scores are set by each licensing board — and, in some places, by the city or county — and they change; confirm yours with your board before you book or buy.