Guide · Updated 2026-10-30

Michigan journey plumber exam: format and study plan

Practice for the Michigan journey plumber written exam with original questions referenced to the 2021 Michigan Plumbing Code: drainage, venting, fixtures, water distribution, backflow, special waste, testing, and isometrics.

The format

125 questions
180 minutes
75% to pass
Open book 2021 MPC, PA 230, PA 407
Exam fee: $100 (PSI).

Test-day rules

Computer-based at PSI test centers, after LARA approves your application.
Open book: the 2021 Michigan Plumbing Code with chapter tabs only, plus printed PA 230 and PA 407, each bound with three staples and unmarked.
A separate practical exam is also required; LARA schedules it by email.

What’s on it

PSI lists the content areas but not how many questions come from each. Our practice uses these estimated weights:

Topic	Our estimated weight	In our mock	Bank
Michigan law and code administration (PA 407, PA 230) Licensing (PA 407) Apprentices (PA 407) Permits (PA 407) State construction code (PA 230) Code administration	6%	8	16
General regulations, definitions, and protection of piping Protection of piping Building sewer depth Pipe support Trenching and backfill Freezing protection Definitions Health and safety Structural safety	8%	10	21
Fixtures, faucets, and fixture fittings Water closets Showers Lavatories and sinks Floor drains Bathtubs Drinking fountains Required facilities Clothes washers Fixture materials	9%	11	22
Water heaters Relief valves Water heater pans Thermal expansion Valves Hot water supply	5%	6	12
Water supply and distribution Water pressure Water service Water distribution Fixture supplies Valves Pipe labeling Materials and joints Disinfection	12%	15	27
Backflow prevention Air gaps Device selection Testing Hazards Device installation	8%	10	19
Sanitary drainage Slope Fixture units Pipe sizing Fittings Cleanouts Sumps and ejectors Building drain	13%	16	32
Indirect and special waste Indirect waste Waste receptors Special wastes	4%	5	10
Vents Vent terminals Vent grades Vent connections Vent sizing Trap-to-vent distance Common vents Wet venting Waste stack vents Circuit venting Combination waste and vent Island venting Air admittance valves Relief vents	12%	15	28
Traps, interceptors, and separators Trap seals Prohibited traps Trap location Building traps Interceptors Trap sizing	6%	8	16
Storm drainage Storm connections Roof drains Secondary drainage Storm sizing Subsoil drains Storm materials	4%	5	10
Inspection and testing DWV tests Final tests Water supply tests Sewer tests Shower liner test Test gauges Responsibilities	6%	7	13
Isometrics and plumbing math Isometric drawings Offsets Pipe volume Slope and grade Hot water math Measuring Fixture unit math	7%	9	15

A study plan

Learn where the tables live in the 2021 Michigan Plumbing Code: fixture units, trap sizes, vent sizing, and water supply sizing.
Practice drainage fixture unit (DFU) totals and pipe sizing until they’re quick.
Know trap and vent rules cold: trap seals, trap arm distances, and vent connections.
Review backflow devices and where each one is required.
Do timed mocks. 125 questions in 180 minutes leaves under 90 seconds per question.

Try 10 free Journey Plumber questions Journey Plumber practice page

Sources: PSI Candidate Information Bulletin 4605 (plumbing, effective Apr 29, 2026) · LARA plumbing exam information. Checked October 30, 2026. Rules and fees change, so confirm with LARA and PSI.

FAQ

How many questions are on the Michigan journey plumber exam?

PSI’s bulletin lists 125 questions in 180 minutes, and you need 75% to pass.

Is the journey plumber exam open book?

Yes. You may bring the 2021 Michigan Plumbing Code (chapter tabs only) and printed copies of PA 230 and PA 407, with no highlighting, marks, or tabs.

Is there a practical exam?

Yes. PSI says journey plumber applicants who applied after December 15, 2021 complete two exams: the written exam and a practical exam you request from LARA by email.

What does the exam cost?

PSI lists a $100 exam fee, valid for one year.

MI Trade Prep is an independent study tool, not affiliated with LARA or PSI.