1.1 Michigan Skilled Trades Regulation Act (PA 407 Article 11) & Licensing Hierarchy

1.1 Michigan Skilled Trades Regulation Act (PA 407 Article 11) & Licensing Hierarchy

Quick Reference: In Michigan, plumbing licensing and administration are governed by Article 11 of the Skilled Trades Regulation Act, 2016 PA 407 (MCL 339.6101 to 339.6133), which repealed and replaced the former State Plumbing Act of 2002 (PA 733). Regulatory authority is vested in the Michigan Department of Licensing and Regulatory Affairs (LARA) and its Bureau of Construction Codes (BCC), working in conjunction with the State Plumbing Board.

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Statutory and Administrative Framework: 2016 PA 407

Prior to 2017, each skilled construction trade in Michigan operated under individual, fragmented statutes. The enactment of the Skilled Trades Regulation Act, 2016 PA 407 (effective April 4, 2017) consolidated the licensing, examination, enforcement, and disciplinary procedures for multiple construction trades into a unified code.

Within PA 407, plumbing is regulated under two core layers:

1. Articles 1 through 6 (General Provisions, MCL 339.5101–339.5611): Establishes standardized department powers, board rules, fee structures, investigation procedures, citation authorities, hearings, and penalties across all licensed trades.
2. Article 11 (Plumbing, MCL 339.6101–339.6133): Prescribes the specific qualifications, examination criteria, scopes of practice, and supervisory ratios for apprentice plumbers, journey plumbers, master plumbers, and plumbing contractors.

Administrative Roles: LARA, BCC, and the State Plumbing Board

• Department of Licensing and Regulatory Affairs (LARA): The principal executive department of Michigan state government responsible for occupational licensing and business regulation.
• Bureau of Construction Codes (BCC): The specialized bureau within LARA that directly oversees code administration, permit issuance, jobsite inspections, and trade examinations.
• State Plumbing Board (MCL 339.6105): Composed of three ex officio members (the LARA director or a representative, the EGLE director or a representative, and a member or employee of EGLE's drinking water and radiologic protection division) plus five members appointed by the governor for 3-year terms: two licensed plumbing contractors who hold a master's license, one licensed master plumber who secures permits, one licensed journey plumber, and one member who represents the general public. E.R.O. No. 2024-2 abolished the 10-year experience membership requirement and made the ex officio members non-voting.

The Board's statutory duties include assisting the department in promulgating administrative rules, reviewing licensing qualifications, approving continuing education programs, and conducting disciplinary hearings against licensees who violate the act or code.

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The Michigan Plumbing Licensing Hierarchy

Michigan establishes a progressive four-tier licensing structure designed to ensure that all individuals installing, altering, or designing plumbing systems possess verified competencies.

+-------------------------------------------------------------+
|                     PLUMBING CONTRACTOR                     |
|  (Business Entity / Employs Full-Time Master Plumber;       |
|   Pulls Permits, Signs Contracts, Holds Liability & WC)     |
+-------------------------------------------------------------+
                              ^
                              |
+-------------------------------------------------------------+
|                        MASTER PLUMBER                       |
|  (Age 18+; 2+ Yrs as Journey; 4,000 Hrs as Journey Plumber; |
|   Passes Master Exam; Plans/Designs/Supervises Installs)    |
+-------------------------------------------------------------+
                              ^
                              |
+-------------------------------------------------------------+
|                       JOURNEY PLUMBER                       |
|  (Age 18+; 6,000 Hrs & 3+ Yrs as Registered Apprentice;     |
|   Passes 125-Q Written [75%, 180 min] & Hands-On Practical)   |
+-------------------------------------------------------------+
                              ^
                              |
+-------------------------------------------------------------+
|                     APPRENTICE PLUMBER                      |
|  (Age 18+; Registered with LARA Within 30 Days of Hire;     |
|   Works Under Direct On-Site Supervision of Journey/Master)  |
+-------------------------------------------------------------+

1. Apprentice Plumber (MCL 339.6117)

An apprentice plumber is an individual registered with LARA who is engaged in learning the plumbing trade by assisting and working under the immediate personal direction and supervision of a licensed journey plumber or master plumber.

• Registration Window: An apprentice must apply for registration with LARA within 30 days after beginning employment in the trade.
• Age Requirement: Must be at least 18 years of age (or enrolled in a recognized secondary vocational or work-study program approved by the department).
• Hour Requirement: To qualify for the journey examination, the apprentice must document not less than 6,000 hours of practical experience in plumbing work acquired over a period of not less than 3 years.
• Supervision Standard: All work performed by an apprentice must occur under the direct, on-site supervision of a licensed journey or master plumber.
• Registration Renewal: Apprentice registration fees under MCL 339.6121 are annual ($15.00). Under MCL 339.6117(2), an apprentice registration becomes invalid 5 years after the date of initial registration unless the apprentice applies for and takes the journey examination; the board may grant an extension on request.

2. Journey Plumber (MCL 339.6115)

A journey plumber is an individual licensed under Article 11 to install, alter, or repair plumbing systems as an employee under the direction and supervision of a licensed plumbing contractor. A journey plumber is certified to work without continuous direct supervision, but cannot pull permits or contract independently.

• Eligibility Criteria:
  1. Minimum age of 18 years.
  2. Completion of not less than 6,000 hours of practical experience over a minimum of 3 years as a registered apprentice under the supervision of a licensed journey or master plumber.
  3. Submission of an application with documented employer affidavits verifying hours and trade experience.
• Application Validity: An approved examination application remains valid for 1 year from the date of department approval. If an applicant fails to take and pass the exam within this 1-year window, a new application and fee must be submitted.
• Examination Format: The examination consists of two distinct components, both administered through PSI and the Bureau of Construction Codes:
  • Written Examination (PSI): 125 multiple-choice questions, 180 minutes, delivered at a PSI test center. The PSI candidate bulletin states that the written examination covers plumbing theory, the practice of plumbing, and knowledge of the state plumbing code, rules and regulations, with questions drawn from drainage systems, vent systems, fixtures, water distribution, backflow prevention, special waste systems, testing and inspections, and the ability to gather information from an isometric drawing. The examination is open book; the three permitted references are the 2021 Michigan Plumbing Code book (chapter tabs only), the State Construction Code Act (1972 PA 230), and the Skilled Trades Regulation Act (2016 PA 407). Online (remote) testing is not available for the Journey Plumber examination.
  • Hands-On Practical Skills Examination (LARA): Required for all journey applications submitted after December 15, 2021. It consists of a copper project and an isometric workbook, and is scheduled by emailing your name and applicant ID to LARA-BCC-Licensing@Michigan.Gov for one of the published examination dates.
• Passing Score: The PSI candidate information bulletin sets the minimum passing score for the Journey Plumber written examination at 75% (94 of 125 questions).
• License Renewal: Under MCL 339.6121(2), the journey plumber license fee is annual ($40.00); journey licenses expire April 30 each year.

3. Master Plumber (MCL 339.6113)

A master plumber is an individual licensed to plan, layout, design, supervise, and install plumbing systems, and who may serve as the designated qualifying master for a plumbing contractor license.

• Eligibility Criteria (MCL 339.6113):
  1. Minimum age of 18 years.
  2. Must hold a journey plumber license issued under Article 11 (or former 2002 PA 733).
  3. Must have gained 4,000 hours of experience in work as a journey plumber over a period of not less than 2 years immediately preceding the date of application.
• Examination: A 130-question written examination, 180 minutes, covering the science and practice of plumbing and knowledge of the state plumbing code, laws, rules and regulations, plus a material take-off practical portion built on a drawing of back-to-back rest rooms, on which the applicant lists the required fittings, vent and drain sizes, and identifies venting methods.
• Passing Score: 75% (PSI candidate information bulletin).
• License Renewal: Under MCL 339.6121(6)-(7), master plumber and plumbing contractor licenses are issued and renewed for 3-year periods at $300.00; they expire April 30 of the renewal year.

4. Plumbing Contractor (MCL 339.6111)

A plumbing contractor is an individual, sole proprietorship, partnership, association, corporation, or other legal entity licensed to engage in the business of contracting for plumbing installation, alteration, or servicing.

• Qualifying Master Requirement: A plumbing contractor must either be a licensed master plumber or designate and employ at least one full-time licensed master plumber of record who represents the contractor in all matters concerning code compliance, permit applications, and jobsite execution.
• Operational Restrictions (MCL 339.6111(7)): If the licensed master plumber who represents a plumbing contractor ceases to represent that contractor, the plumbing contractor has 30 days to designate another licensed master plumber as its representative and must notify the department in writing of the change. A licensed master plumber may represent only one plumbing contractor at a time (MCL 339.6113(3)).
• Permit Authority (MCL 339.6125): The state or a governmental subdivision issues a plumbing permit only to a licensed plumbing contractor, except that (a) a full-time employed master plumber may secure permits for plumbing on premises owned or occupied by the business that employs him or her, under an annual affidavit; (b) a homeowner may secure a permit to install his or her own plumbing in his or her single-family dwelling (MCL 339.6107(2)(d)); and (c) where licensed work is performed without compensation for a charitable organization on a 1- to 4-family dwelling, the property owner may obtain the permit.

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Licensing Hierarchy Summary Table

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Jobsite Apprentice Ratios: MCL 339.6117a Mandate

One of the most critical regulatory provisions tested on the Michigan Journeyman Plumber examination is the statutory ratio governing jobsite apprentice supervision. To ensure public safety, structural integrity, and rigorous field training, Michigan enacted MCL 339.6117a, establishing strict legal limits on the number of apprentices a licensed tradesperson may supervise on a jobsite.

+-------------------------------------------------------------------------+
|                   MICHIGAN JOBSITE APPRENTICE RATIO                     |
|                           (MCL 339.6117a)                               |
|                                                                         |
|   1 Licensed Journey OR Master Plumber  :  NOT MORE THAN 2 Apprentices  |
|                                                                         |
|   Example A: 1 Journeyman on site  -> Max 2 Registered Apprentices      |
|   Example B: 2 Journeymen on site  -> Max 4 Registered Apprentices      |
|   Example C: 1 Journeyman + 3 Apprentices -> STATUTORY VIOLATION!       |
+-------------------------------------------------------------------------+

Key Provisions of the Ratio Statute:

1. Effective Date: Effective April 2, 2025, the ratio established under MCL 339.6117a is mandatory statewide across all residential, commercial, and industrial construction projects.
2. Ratio Limit: On any jobsite where plumbing work is being performed, there shall be a ratio of not more than 2 registered apprentice plumbers to 1 licensed journey plumber or master plumber.
3. Direct Physical Supervision: The licensed journey or master plumber must be physically present on the jobsite and providing direct personal direction and oversight. An off-site master plumber or a journey plumber operating at another location cannot be counted to satisfy the ratio for working apprentices.
4. Enforcement and Penalties (MCL 339.6117a(2)): The statute imposes escalating penalties on the plumbing contractor that violates the ratio:
   • First violation: a $5,000.00 administrative fine.
   • Second violation: a $10,000.00 administrative fine.
   • Third violation: suspension of the plumbing contractor license for not less than 90 days; after 90 days the license may be reinstated if the contractor passes the plumbing contractor examination described in MCL 339.6111. Money collected as an administrative fine is paid to the enforcing agency that discovered the violation, and the department is entitled to actual costs and attorney fees related to the investigation and adjudication.

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License Renewal, Continuing Education & Disciplinary Actions

Triennial Renewal System

Michigan does not use a single renewal cycle for all plumbing credentials. Under MCL 339.6121:

• Journey plumbers and apprentices renew annually. The annual fee is $40.00 for a journey plumber license and $15.00 for an apprentice registration. Journey licenses expire April 30 each year.
• Master plumber and plumbing contractor licenses are issued and renewed for periods of up to 3 years at $300.00, expiring April 30 of the renewal year. Where an initial license or relicensure is issued at a time other than between April 30 and June 30 of the year the department issues renewal licenses, the fee is prorated yearly.
• Late Renewal (60 days): A license or apprentice registration must be renewed not more than 60 days after the renewal date. A holder that does not renew within 60 days of expiration may be relicensed only by applying to the board and paying the annual renewal fee plus a relicensure fee of $50.00 (journey), $20.00 (apprentice), or $100.00 (master or plumbing contractor).
• Reinstatement vs. Reexamination: An individual requesting renewal within 3 years after the license expired is not subject to reexamination but must pay the relicensure fee and the annual renewal fee for each year the license was not renewed. An individual who fails to renew for more than 3 consecutive years must again meet the experience requirements and take the examination for that class of license.

Code Update Continuing Education

Whenever the Bureau of Construction Codes formally updates and promulgates a new edition of the Michigan Plumbing Code (such as the transition to the 2021 MPC / Part 7 Rules), the State Plumbing Board requires licensed journey and master plumbers to complete mandatory code update courses approved by the Board within a prescribed timeframe. These hours ensure that all practitioners understand Michigan-specific amendments and national code revisions.

Unlicensed Practice Violations (MCL 339.5601)

MCL 339.5601(1) prohibits a person from engaging in, or attempting to engage in, the practice of an occupation regulated under the act, or using a title designated in the act, without a license. A person whose license is suspended, revoked, or lapsed is considered unlicensed. Penalties escalate:

• First violation: misdemeanor punishable by a fine of not more than $500.00 or imprisonment for not more than 90 days, or both.
• Second violation: misdemeanor punishable by a fine of not more than $1,000.00 or imprisonment for not more than 1 year, or both.
• Third or subsequent violation: felony punishable by a fine of not more than $25,000.00 or imprisonment for not more than 5 years, or both.
• Restitution and injunctive relief: Penalties may include restitution, and an affected person may pursue injunctive relief; a successful plaintiff is entitled to actual costs and attorney fees.

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Realistic Exam Scenario: Jobsite Supervision & Ratio Compliance

Exam Scenario: Great Lakes Mechanical Contractors holds a plumbing contract for a new five-story medical office building in Lansing. On a Tuesday morning, the jobsite has the following personnel installing sanitary drainage stacks and water distribution risers:

• 1 Licensed Master Plumber (acting as general superintendent for the entire region, spends 45 minutes on site, then departs for another jobsite)
• 2 Licensed Journey Plumbers (actively working on site the entire shift)
• 5 Registered Apprentice Plumbers (installing copper supply lines and PVC drainage piping)

A BCC plumbing inspector arrives at 1:30 PM to conduct a rough-in inspection. How will the inspector evaluate the jobsite ratio under MCL 339.6117a?

Code Analysis:

1. Active Licensed Personnel: The Master Plumber is off-site and cannot be counted toward jobsite supervision. Only the 2 Journey Plumbers physically present on site can supervise apprentices.
2. Statutory Maximum: Under MCL 339.6117a, the legal ratio is not more than 2 apprentices per 1 licensed journey or master plumber present. With 2 journey plumbers on site, the maximum allowable number of apprentices is: $\text{Max Apprentices} = 2 \times 2 = 4 \text{ apprentices}$
3. Violation Determination: There are 5 apprentices performing plumbing work, which exceeds the statutory limit by 1.
4. Inspector Action: The inspector will cite the contractor for an illegal apprentice-to-journeyman ratio under MCL 339.6117a, issue a Stop Work Order on uninspected or improperly supervised work, and report the violation to the State Plumbing Board for administrative sanctions under MCL 339.5601.