Michigan Plumbing Contractor Exam – 400
Practice Questions with Verified Answers &
Detailed Rationales (2026 Updated)
1. Which Michigan agency administers plumbing contractor licensing requirements?
A. Michigan Department of Transportation
B. Michigan Department of Licensing and Regulatory Affairs (LARA)
C. Michigan Department of Treasury
D. Michigan Department of Education
Answer: B
Rationale: LARA's Bureau of Construction Codes handles Michigan plumbing licensing and
examination information.
2. What code is currently identified by Michigan LARA as the Michigan Plumbing Code?
A. 2015 IPC
B. 2018 IPC
C. 2021 Michigan Plumbing Code
D. 2024 Michigan Plumbing Code
Answer: C
Rationale: LARA currently identifies the 2021 Michigan Plumbing Code as the current code,
effective March 12, 2024.
3. Which organization administers the written plumbing licensing examinations for Michigan?
A. OSHA
B. ICC
C. PSI
D. NFPA
Answer: C
Rationale: Michigan LARA states that PSI schedules and proctors the examinations, while the
Bureau of Construction Codes creates the exams.
,4. Which person must be associated with a Michigan plumbing contractor license?
A. Licensed apprentice
B. Licensed Master Plumber
C. Licensed building inspector
D. Licensed electrician
Answer: B
Rationale: A plumbing contractor must hold a Master Plumber license or employ a Master
Plumber as the representative.
5. Can a Michigan plumbing contractor license be issued without Master Plumber
representation?
A. Yes
B. Only for residential work
C. Only for commercial work
D. No
Answer: D
Rationale: LARA specifically states that the contractor license will not be issued without Master
Plumber representation.
6. Which person may apply for a Michigan plumbing contractor license?
A. Any plumbing apprentice
B. Only a licensed journey plumber
C. A sole proprietor, qualifying partner, corporate officer, or LLC member as specified by statute
D. Any employee of a plumbing company
Answer: C
Rationale: Michigan's licensing information identifies these business roles as eligible applicants
under the statutory requirements.
7. How old must an applicant generally be for a Michigan plumbing contractor license?
A. 16
B. 18
C. 21
D. 25
Answer: B
Rationale: The current Michigan contractor application states that the applicant must be at
least 18 years old.
,8. How long must a Michigan Master Plumber have worked as a journey plumber before
applying for the Master Plumber license?
A. 6 months
B. 1 year
C. 2 years
D. 5 years
Answer: C
Rationale: LARA states that a Master Plumber applicant needs 4,000 hours of journey-plumber
experience over at least two years immediately preceding the application.
9. How many hours of experience are required for the Michigan Master Plumber pathway
described by LARA?
A. 2,000 hours
B. 3,000 hours
C. 4,000 hours
D. 6,000 hours
Answer: C
Rationale: LARA specifies 4,000 hours of journey-plumber experience over at least two years.
10. What experience requirement does LARA list for a Journey Plumber applicant?
A. 2,000 hours over 1 year
B. 4,000 hours over 2 years
C. 6,000 hours over at least 3 years as a registered plumbing apprentice
D. 10,000 hours over 5 years
Answer: C
Rationale: Michigan lists at least 6,000 hours over not less than three years as an actively
registered plumbing apprentice under appropriate supervision.
11. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Remove minerals from water
, Answer: B
Rationale: A trap maintains a water seal that prevents sewer gases from entering occupied
spaces through the drainage system.
12. What is the water held in a plumbing trap commonly called?
A. Pressure seal
B. Hydraulic seal
C. Water seal
D. Air lock
Answer: C
Rationale: The water retained in the trap forms the water seal between the drainage system
and the fixture.
13. What is the primary purpose of a drainage-system vent?
A. Increase hot-water temperature
B. Supply combustion air
C. Protect trap seals and allow proper drainage-system airflow
D. Increase pipe pressure
Answer: C
Rationale: Proper venting allows air movement in the drainage system and helps protect trap
seals from pressure conditions that could cause siphonage or backpressure.
14. What can happen when a trap is siphoned?
A. Its water seal can be lost
B. Its pipe becomes larger
C. Water pressure increases
D. The fixture becomes electrically grounded
Answer: A
Rationale: Siphonage can remove water from the trap, destroying the water seal and
potentially allowing sewer gases into the building.
15. What is backflow?
A. Normal downstream flow
B. Reverse flow of water or other substances into the potable-water system
C. Flow through a vent
D. Flow from a fixture to a drain
Practice Questions with Verified Answers &
Detailed Rationales (2026 Updated)
1. Which Michigan agency administers plumbing contractor licensing requirements?
A. Michigan Department of Transportation
B. Michigan Department of Licensing and Regulatory Affairs (LARA)
C. Michigan Department of Treasury
D. Michigan Department of Education
Answer: B
Rationale: LARA's Bureau of Construction Codes handles Michigan plumbing licensing and
examination information.
2. What code is currently identified by Michigan LARA as the Michigan Plumbing Code?
A. 2015 IPC
B. 2018 IPC
C. 2021 Michigan Plumbing Code
D. 2024 Michigan Plumbing Code
Answer: C
Rationale: LARA currently identifies the 2021 Michigan Plumbing Code as the current code,
effective March 12, 2024.
3. Which organization administers the written plumbing licensing examinations for Michigan?
A. OSHA
B. ICC
C. PSI
D. NFPA
Answer: C
Rationale: Michigan LARA states that PSI schedules and proctors the examinations, while the
Bureau of Construction Codes creates the exams.
,4. Which person must be associated with a Michigan plumbing contractor license?
A. Licensed apprentice
B. Licensed Master Plumber
C. Licensed building inspector
D. Licensed electrician
Answer: B
Rationale: A plumbing contractor must hold a Master Plumber license or employ a Master
Plumber as the representative.
5. Can a Michigan plumbing contractor license be issued without Master Plumber
representation?
A. Yes
B. Only for residential work
C. Only for commercial work
D. No
Answer: D
Rationale: LARA specifically states that the contractor license will not be issued without Master
Plumber representation.
6. Which person may apply for a Michigan plumbing contractor license?
A. Any plumbing apprentice
B. Only a licensed journey plumber
C. A sole proprietor, qualifying partner, corporate officer, or LLC member as specified by statute
D. Any employee of a plumbing company
Answer: C
Rationale: Michigan's licensing information identifies these business roles as eligible applicants
under the statutory requirements.
7. How old must an applicant generally be for a Michigan plumbing contractor license?
A. 16
B. 18
C. 21
D. 25
Answer: B
Rationale: The current Michigan contractor application states that the applicant must be at
least 18 years old.
,8. How long must a Michigan Master Plumber have worked as a journey plumber before
applying for the Master Plumber license?
A. 6 months
B. 1 year
C. 2 years
D. 5 years
Answer: C
Rationale: LARA states that a Master Plumber applicant needs 4,000 hours of journey-plumber
experience over at least two years immediately preceding the application.
9. How many hours of experience are required for the Michigan Master Plumber pathway
described by LARA?
A. 2,000 hours
B. 3,000 hours
C. 4,000 hours
D. 6,000 hours
Answer: C
Rationale: LARA specifies 4,000 hours of journey-plumber experience over at least two years.
10. What experience requirement does LARA list for a Journey Plumber applicant?
A. 2,000 hours over 1 year
B. 4,000 hours over 2 years
C. 6,000 hours over at least 3 years as a registered plumbing apprentice
D. 10,000 hours over 5 years
Answer: C
Rationale: Michigan lists at least 6,000 hours over not less than three years as an actively
registered plumbing apprentice under appropriate supervision.
11. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Remove minerals from water
, Answer: B
Rationale: A trap maintains a water seal that prevents sewer gases from entering occupied
spaces through the drainage system.
12. What is the water held in a plumbing trap commonly called?
A. Pressure seal
B. Hydraulic seal
C. Water seal
D. Air lock
Answer: C
Rationale: The water retained in the trap forms the water seal between the drainage system
and the fixture.
13. What is the primary purpose of a drainage-system vent?
A. Increase hot-water temperature
B. Supply combustion air
C. Protect trap seals and allow proper drainage-system airflow
D. Increase pipe pressure
Answer: C
Rationale: Proper venting allows air movement in the drainage system and helps protect trap
seals from pressure conditions that could cause siphonage or backpressure.
14. What can happen when a trap is siphoned?
A. Its water seal can be lost
B. Its pipe becomes larger
C. Water pressure increases
D. The fixture becomes electrically grounded
Answer: A
Rationale: Siphonage can remove water from the trap, destroying the water seal and
potentially allowing sewer gases into the building.
15. What is backflow?
A. Normal downstream flow
B. Reverse flow of water or other substances into the potable-water system
C. Flow through a vent
D. Flow from a fixture to a drain
