- MI-JP is the Michigan Journey Plumber written exam: 125 questions, 180 minutes, open-book, 75% to pass.
- LARA (Bureau of Construction Codes) licenses; PSI Services LLC administers the computer-based test at physical centers only.
- Candidates need 6,000+ hours over at least three years of documented, notarized apprenticeship experience before applying.
- PSI charges $100 per written attempt; LARA's initial license fee is $40, with $40 annual renewal by April 30.
What Is MI-JP?
MI-JP stands for the Michigan Journey Plumber License Exam - the written examination that licensed plumbing apprentices in Michigan must pass to move up to journey plumber status. It is not a trade association credential or a national certificate; it is a state-regulated licensing exam tied directly to Michigan's Skilled Trades Regulation Act and the 2021 Michigan Plumbing Code. Passing MI-JP is one of two required steps toward the journey plumber license, the other being a separate hands-on practical examination administered by the Bureau of Construction Codes (BCC).
If you're just starting to research this credential, it helps to separate the written exam from everything else attached to the license. This page focuses specifically on the PSI-administered written test. For a deeper breakdown of what's tested, see the MI-JP Exam Domains 2026: Complete Guide to All 3 Content Areas, and for a structured prep plan, check the MI-JP Study Guide 2026: How to Pass on Your First Attempt.
Who Runs the MI-JP Exam
Two organizations control different halves of this process, and understanding the split matters for scheduling and troubleshooting:
- Michigan Department of Licensing and Regulatory Affairs (LARA), Bureau of Construction Codes (BCC): Owns licensing. LARA reviews and approves your application, verifies your apprenticeship hours, and issues the license once both exams are passed.
- PSI Services LLC: The third-party testing vendor. PSI delivers the written exam at physical test centers and manages scheduling once LARA has approved you to test.
You cannot schedule with PSI on your own initiative - LARA approval comes first. This two-stage gate trips up a lot of first-time applicants, which is why the MI-JP Requirements 2026: Eligibility, Prerequisites & How to Qualify guide walks through the sequence in detail.
Exam Format and Question Style
The MI-JP written exam has a specific, fixed structure:
- 125 questions, multiple-choice, computer-based
- 180 minutes total testing time
- Open-book - approved code books and statutes are allowed at the workstation
- 75% minimum score required to pass
- Administered in person at a PSI test center - there is no remote or online-proctored version for Journey Plumber candidates
Because the exam is open-book, the questions are written to test whether you can locate and correctly apply code language under time pressure, not just recall it from memory. That changes how you should prepare - knowing the table of contents and index of the Michigan Plumbing Code cold is often more valuable than memorizing exact section numbers. The How Hard Is the MI-JP Exam? Complete Difficulty Guide 2026 article covers why open-book format doesn't necessarily make this exam easy, and the MI-JP Passing Score 2026: Exactly What You Need to Pass page breaks down exactly what 75% means in practice across 125 questions.
Key Takeaway
Open-book does not mean open-note. Highlighting, underlining, and handwritten annotations in your code books are prohibited - practice navigating a clean, untabbed-beyond-chapter-tabs code book before test day.
The Three MI-JP Domains
PSI's candidate bulletin organizes the written exam into three broad content areas. Each one draws from the 2021 Michigan Plumbing Code, the State Construction Code Act (1972 PA 230), and the Skilled Trades Regulation Act (2016 PA 407).
Domain 1: Plumbing Theory
Covers the underlying scientific and engineering principles behind how plumbing systems function - hydraulics, venting theory, pressure and flow relationships, and the reasoning behind code requirements rather than just the requirements themselves.
- Why traps, vents, and drainage slopes are sized the way they are
- Pressure and siphonage effects on trap seals
- Material properties relevant to water distribution and waste systems
Domain 2: The Practice of Plumbing
Focuses on real-world application - installation methods, fixture setup, testing procedures, and reading job documentation correctly.
- Interpretation of isometric drawings and plumbing plans
- Fixture installation and water distribution layout
- Testing and inspection procedures for completed systems
Domain 3: Knowledge of the State Plumbing Code, Rules and Regulations
Tests direct familiarity with the Michigan Plumbing Code and the statutes governing plumbing work in the state.
- Backflow prevention and special waste system requirements
- Vent system and drainage system code provisions
- Licensing rules under the Skilled Trades Regulation Act
Beyond the three named domains, the PSI bulletin's broader coverage notes make clear that detailed preparation must also include drainage systems, vent systems, fixtures, water distribution, backflow prevention, special waste systems, testing and inspections, and isometric drawing interpretation - these threads run through all three domains rather than sitting in isolated buckets. For a question-by-question breakdown of how these topics map to each domain, see MI-JP Exam Domains 2026: Complete Guide to All 3 Content Areas.
Eligibility and Apprenticeship Hours
You can't sit for MI-JP casually - LARA requires documented field experience before you're eligible to apply:
- Minimum age of 18
- At least 6,000 hours of plumbing work
- Accumulated over at least three years
- As an actively registered plumbing apprentice working under a licensed master or journey plumber
- Supported by notarized employer experience statements
LARA reviews and approves this documentation before PSI will schedule you. This is often the slowest part of the whole process, since gathering notarized statements from past and current employers takes coordination. Full instructions on assembling this paperwork are covered in MI-JP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Fees, Application, and Scheduling
MI-JP involves two separate fee streams that candidates frequently conflate:
| Item | Amount | Paid To |
|---|---|---|
| Written exam attempt | $100 | PSI Services LLC |
| Initial license application | $40 | LARA |
| Annual license renewal | $40 | LARA (due by April 30 each year) |
PSI allows repeat attempts on the written exam, each requiring a new $100 fee, but repeat attempts must still fall within your active one-year application window. A passing score does not transfer forward to a future application - if your window closes before you pass both the written and practical exams, you'll need to reapply and start the clock again. For a full cost picture including renewal cycles, see MI-JP Certification Cost 2026: Complete Pricing Breakdown.
The PSI candidate bulletin governing this exam is effective April 29, 2026, so if you're scheduling around that date, confirm which version of the bulletin applies to your application window. Scheduling logistics, deadlines, and how far in advance you need to book are detailed in MI-JP Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Approved References and Code Books
Because MI-JP is open-book, what you're allowed to bring into the test center is tightly controlled:
- 2021 Michigan Plumbing Code
- State Construction Code Act (1972 PA 230)
- Skilled Trades Regulation Act (2016 PA 407)
Code-book chapter tabs are permitted, but highlighting, underlining, handwritten notes, and any other markings inside the books are prohibited. If you print statutory references from the BCC website instead of using a bound code book, those printouts must be separate documents, each bound with three staples along the left edge, with no markings or tabs, and no additional loose or attached papers. Bringing an improperly prepared reference set can create problems at check-in, so build your reference materials well before test day rather than the night before.
Key Takeaway
Set up your code books and any printed statutes exactly per PSI's binding and marking rules weeks in advance - test center staff will inspect materials at check-in, and non-compliant references can be rejected on the spot.
The Practical Examination
Passing the written MI-JP exam is only half the licensing requirement. BCC also administers a separate hands-on practical examination, and the published practical session runs from 10:00 a.m. to 12:30 p.m. Scheduling requests for the practical must meet a 30-day cutoff, so this isn't something you can arrange at the last minute. Both exams - written and practical - need to be completed and passed within the same one-year application period tied to your LARA approval.
This article focuses on the PSI written exam specifically, but if you're mapping out your full path to licensure, treat the practical as a parallel project with its own scheduling deadline, not an afterthought once you've cleared the written portion.
Who Needs MI-JP and Who Hires For It
MI-JP is required for any registered plumbing apprentice in Michigan who has completed the required hours and wants to move into a journey plumber role - a step up in scope of work, supervisory responsibility, and typically pay. Employers who hire journey plumbers include mechanical contractors, plumbing and HVAC firms, municipal utilities, and property management or facilities companies that need licensed staff to sign off on plumbing work without direct master-plumber supervision on every task.
Because the license is state-issued and tied to Michigan code specifically, it doesn't automatically transfer the way some national certifications do - it's a Michigan-specific credential recognized by Michigan employers and inspectors. If you're weighing whether pursuing this license makes sense for your career stage, Is the MI-JP Certification Worth It? Complete ROI Analysis 2026 and MI-JP Salary Guide 2026: Complete Earnings Analysis go deeper on that decision, and MI-JP Jobs looks at where journey plumbers typically work after licensing.
Scheduling Your Study Around the Two-Gate Process
Because MI-JP requires LARA approval before PSI scheduling, and because the practical and written exams share one deadline, it's worth timing your domain review around your application status rather than an arbitrary calendar. A simple approach: while your LARA application and notarized experience statements are under review, spend that waiting period on Domain 1 (plumbing theory) and Domain 3 (code and rules), since those benefit most from slow, repeated reading of the actual code text. Once you have a confirmed testing window from PSI, shift toward Domain 2 (the practice of plumbing) - isometric drawings, fixture layouts, and testing/inspection procedures - because that domain rewards recent, active practice more than long-term memorization.
Build Code Familiarity
- Read through the 2021 Michigan Plumbing Code sections on drainage, venting, and water distribution
- Set up chapter tabs (no markings) in your code books
- Review the Skilled Trades Regulation Act provisions relevant to licensing
Sharpen Application Skills
- Practice reading and interpreting isometric drawings under a timer
- Run through backflow prevention and special waste system scenarios
- Take timed practice questions to build 125-question, 180-minute pacing
For a broader library of timed questions across all three domains, the practice tests on MI-JP Exam Prep are built specifically around this exam's format rather than generic plumbing trivia.
If you want a condensed, one-page reference of the facts most likely to trip up candidates - fee amounts, hour requirements, and domain boundaries - the MI-JP Cheat Sheet 2026: One-Page Review of Must-Know Facts is built for quick review in the days before your test date. And for a data-grounded look at how candidates typically perform, see MI-JP Pass Rate 2026: What the Data Shows.
Frequently Asked Questions
No. MI-JP as covered here refers to the PSI-administered written exam. A separate BCC hands-on practical examination is also required, and both must be passed within the same one-year application period.
No. Journey Plumber candidates test in person at a PSI test center; there is no remote-proctoring option for this exam.
PSI allows repeat attempts, each requiring a new $100 exam fee, but you must still pass within your active one-year LARA application window since a pass does not transfer between applications.
Yes, the exam is open-book using the 2021 Michigan Plumbing Code, the State Construction Code Act, and the Skilled Trades Regulation Act. Chapter tabs are allowed; highlighting, underlining, or handwritten notes are not.
Annually, by April 30, for a $40 renewal fee. A board-approved code-update course is also required within one year after Michigan adopts a new plumbing code.
MI-JP is a state-controlled licensing milestone, not a generic trade quiz - every fee, deadline, and content area traces back to LARA and PSI's specific rules for Michigan journey plumbers. For related definitional questions, see MI-JP Meaning, What Does MI-JP Stand For?, and MI-JP Certification, or start practicing directly at MI-JP Exam Prep.