Guide · Updated 2026-10-30

Michigan master plumber exam: format and study plan

Practice for the Michigan master plumber exam with original questions on the 2021 Michigan Plumbing Code and the Skilled Trades Regulation Act: sizing, storm drains, special waste, backflow, testing, and Michigan plumbing law.

The format

130 questions
180 minutes
75% to pass
Open book 2021 MPC (PA 230 and 407 on screen)
Exam fee: $100 (PSI).

Test-day rules

Computer-based at PSI test centers, after LARA approves your application.
Open book: bring the 2021 Michigan Plumbing Code with chapter tabs only. PA 230 and PA 407 are provided on screen.
The exam includes a material take-off: a back-to-back restroom drawing where you list fittings, size drains and vents, and identify venting methods.

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: licensing, contractors, and permits (PA 407, PA 230) Master licensing (PA 407) Contractor licensing (PA 407) Fees and renewal (PA 407) Permits (PA 407) Exemptions (PA 407) Inspectors (PA 407) State construction code (PA 230) Complaints (PA 407)	9%	12	22
Code administration and general regulations Code scope Code adoption Permits Health and safety General regulations	7%	9	17
Fixture requirements and facilities Fixture calculations Separate facilities Access to facilities Compartments and partitions Fixture substitution Floor drains Tempered water Emergency fixtures Flushing devices Fixture fittings Drinking fountains	9%	12	21
Water heaters and hot water systems Relief valve discharge Hot water systems Hot water math Thermal expansion Water heater pans Relief valves	5%	7	12
Water supply design and distribution Pressure design Pipe sizing Valves Materials Non-potable systems Water tanks Disinfection Thermal expansion Water service	11%	14	26
Backflow protection Hazard assessment Device selection Device installation Testing Air gaps Cross connections	8%	10	19
Sanitary drainage design Drain sizing Stack sizing Branch sizing Stack offsets Fixture units Future fixtures Building sewer Sumps and ejectors Cleanouts Fittings	13%	17	30
Venting design Vent terminals Stack offsets Relief vents Vent sizing Wet venting Circuit venting Combination waste and vent Island venting Air admittance valves Trap-to-vent distance Common vents Waste stack vents Single stack Vent connections	12%	16	28
Storm drainage Storm sizing Secondary drainage Storm connections Roof drains Storm math Subsoil drainage Storm materials Controlled flow	7%	9	17
Interceptors, special waste, and indirect waste Grease interceptors Oil and sand Interceptor rules Indirect waste Special wastes	7%	9	17
Inspection and testing Required tests Inspections Backflow inspection Water service test	5%	6	12
Material take-off: back-to-back restrooms Fixture count DFU take-off Carriers and fittings Pipe take-off Cost take-off Tempered water take-off Vent take-off	7%	9	15

A study plan

Practice storm drain sizing by roof area and rainfall rate, and building drain and sewer sizing by fixture units.
Know the special waste rules: interceptors, separators, and chemical waste.
Read PA 407’s plumbing sections. It’s on screen during the exam, but you need to know where to look.
Work a back-to-back restroom take-off by hand: fittings, drain and vent sizes, and venting methods.
Do timed mocks at test-day pace.

Try 10 free Master Plumber questions Master 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 master plumber exam?

PSI’s bulletin lists 130 questions in 180 minutes. You need 75% to pass.

Can I bring PA 407 to the master plumber exam?

No. PSI provides PA 230 and PA 407 on screen for the master exam. You bring only the 2021 Plumbing Code with chapter tabs.

What is the material take-off?

A drawing of back-to-back restrooms with all needed data. Using the plumbing code, you list the fittings, size the drains and vents, and identify venting methods.

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.