- The WI-MP exam has exactly two domains: Part 1 (110 questions, 4 hours) and Part 2 (132 questions, 4 hours).
- Each part costs $95, is open book, and requires a 70% passing score.
- Part 2 carries the larger content share, so it deserves more of your prep time.
- Only DSPS-approved bound references are allowed - no loose paper, tabs, sticky notes, or practice exams in the room.
WI-MP Exam Structure Overview
The Wisconsin Master Plumber License Examination (WI-MP) is administered on behalf of the Wisconsin Department of Safety and Professional Services (DSPS) through Pearson VUE, with testing available at six in-state Pearson centers. Unlike single-sitting licensing exams in other trades, the WI-MP is split into two distinct, separately scheduled parts. Understanding what each part covers - and how the two differ in scope and length - is the foundation of any serious prep plan. If you haven't yet mapped out your overall study approach, the WI-MP Study Guide 2026: How to Pass on Your First Attempt is a good companion to this domain breakdown.
Both parts are computer-based, open book, and scored against a 70% passing threshold. Each part costs $95 to sit, and each is allotted 4 hours to complete. The exam is organized into exactly two content areas rather than a long list of weighted subtopics, which simplifies planning but raises the stakes for each domain - there's no diluting a weak area across five or six smaller sections.
Domain 1: Master Plumber - Part 1
Domain 1 is the first of the two WI-MP content areas and consists of 110 questions administered over 4 hours. As the shorter of the two parts, Part 1 is often where candidates build early momentum, but it should not be treated as a warm-up. Because the passing score of 70% applies independently to each part, a strong Part 1 score doesn't offset a weak Part 2 attempt, and vice versa.
Domain 1: Master Plumber - Part 1
Candidates should treat Part 1 as a full, standalone licensing exam that draws on the same code knowledge and field experience required by the journeyman-to-master pathway. Success here depends on comfort navigating your approved reference materials quickly under a fixed 4-hour clock.
- 110 scored questions to complete within the 4-hour window
- Open-book format built around DSPS-approved bound references
- Requires efficient reference navigation, not memorization of code text
- Scored independently against the 70% passing threshold
Because the exam is open book, raw memorization matters less than the ability to locate the right section of your approved materials quickly. Candidates who spend their prep time building a mental index of where key rules live in their reference book - rather than trying to memorize page contents outright - tend to move through Part 1's 110 questions with less time pressure. For a deeper look at how tough this pacing actually is in practice, see How Hard Is the WI-MP Exam? Complete Difficulty Guide 2026.
Domain 2: Master Plumber - Part 2
Domain 2 is the second content area and the larger of the two parts, with 132 questions administered over the same 4-hour time limit as Part 1. Because Part 2 has more questions in the same amount of time, the average time-per-question is tighter, which makes reference-navigation speed even more important here than in Part 1.
Domain 2: Master Plumber - Part 2
As the domain with the larger share of exam content, Part 2 typically requires more study hours than Part 1. Candidates should expect the question volume to demand sharper time management even though the open-book format remains the same.
- 132 scored questions within a 4-hour session
- Largest content share of the two-part WI-MP structure
- Same open-book rules and 70% passing score as Part 1
- Tighter average time per question than Part 1 due to higher question count
Key Takeaway
Because Domain 2 (Part 2) has 22 more questions than Domain 1 (Part 1) within the same 4-hour limit, allocate proportionally more review time to Part 2 and rehearse your reference-lookup speed specifically against that tighter pace.
Part 1 vs. Part 2 at a Glance
Seeing both domains side by side makes it easier to plan your registration and study calendar. Both parts share the same fee structure, format, and passing standard - the differences are in volume and, correspondingly, the depth of review each one demands.
| Feature | Domain 1: Part 1 | Domain 2: Part 2 |
|---|---|---|
| Number of Questions | 110 | 132 |
| Time Allotted | 4 hours | 4 hours |
| Exam Fee | $95 | $95 |
| Format | Open book, computer-based | Open book, computer-based |
| Passing Score | 70% | 70% |
| Content Share | Smaller | Larger |
For a full walkthrough of exactly how the 70% threshold is applied on each part, read WI-MP Passing Score 2026: Exactly What You Need to Pass. And if you're curious how these two domains combine to affect overall outcomes across the candidate pool, WI-MP Pass Rate 2026: What the Data Shows looks at that pattern in more detail.
Registration, Fees, and Reference Materials
Each domain is registered and paid for separately: $95 per part, for a combined $190 if you sit both in the same testing cycle. Both parts are scheduled through Pearson VUE at one of the six in-state testing centers, and passing results remain valid for one year - so if you pass Part 1 first, plan to sit Part 2 within that window rather than letting the clock run out.
Because both domains are open book, what you're allowed to bring into the testing room matters as much as what you study. DSPS permits only approved bound references and notes; loose paper, removable tabs, sticky notes, paperclips, and practice exams are explicitly prohibited. Architect and engineer scale rulers are permitted, which is worth knowing if either domain touches drawing-based or measurement-based questions.
For a complete breakdown of every fee associated with the license - including what happens after you pass both domains - see WI-MP Certification Cost 2026: Complete Pricing Breakdown. The license itself runs on a four-year term, expiring March 31, and renews for $500 with 24 approved continuing education hours required - details worth knowing before you even sit for Part 1.
Who Qualifies and Who Hires Master Plumbers
Before registering for either domain, candidates must meet DSPS eligibility requirements. The standard pathway requires at least 1,000 hours per year working as a licensed Wisconsin Journeyman Plumber for three years, or an approved plumbing-related engineering degree. Separate comity pathways exist for applicants with qualifying out-of-state apprenticeships, licenses, or experience, which can shorten the road to sitting for Domain 1 and Domain 2 if you're relocating to Wisconsin. A full explanation of each pathway is available in WI-MP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Once licensed, Master Plumbers are typically sought by mechanical contractors, plumbing firms, municipal utilities, and design-build companies that need a credentialed professional to pull permits, supervise journeyman crews, and sign off on installations that fall under DSPS oversight. If you're weighing whether the credential is worth the two-part exam investment, Is the WI-MP Certification Worth It? Complete ROI Analysis 2026 and WI-MP Salary Guide 2026: Complete Earnings Analysis both dig into that question in depth.
Scheduling Your Domain Prep
Because the WI-MP only has two domains, your prep calendar doesn't need dozens of subtopic blocks - it needs a clear split between Part 1 and Part 2, weighted toward the larger domain. A short spaced-repetition cycle works well here specifically because each domain is self-contained: review your reference book's index for one domain, take a break, then switch.
Domain 1: Part 1 Foundations
- Build a personal index of your approved bound reference for Part 1 topics
- Practice locating code sections under time pressure to simulate the 4-hour, 110-question pace
- Confirm your reference materials meet DSPS's approved, bound-only standard
Domain 2: Part 2 Deep Dive
- Extend your index to the larger Part 2 content share
- Drill pacing against 132 questions in 4 hours - tighter than Part 1's ratio
- Re-test reference lookup speed since Part 2 leaves less slack per question
Cross-Domain Review
- Rotate between Domain 1 and Domain 2 materials in short blocks
- Confirm your Pearson VUE appointments are scheduled within the one-year passing-result window
- Review exact testing dates and center locations
For exact dates, deadlines, and how far in advance to book each Pearson VUE session, check WI-MP Exam Dates 2026: Testing Windows, Deadlines & Scheduling. If you want a condensed reference for last-minute review of both domains, the WI-MP Cheat Sheet 2026: One-Page Review of Must-Know Facts summarizes the highest-value facts in one page. And once you're ready to test your recall under realistic time constraints for both Part 1 and Part 2, practicing with timed questions before exam day is one of the simplest ways to confirm your pacing plan actually holds up.
Beyond the exam itself, ongoing skill-building matters for renewal and career growth. Formal coursework and apprenticeship-adjacent programs are covered in WI-MP Training, while current openings for licensed professionals are tracked in WI-MP Jobs. Reviewing both can help you see how Domain 1 and Domain 2 content map onto real job responsibilities after licensure.
Frequently Asked Questions
Exactly two: Domain 1 (Master Plumber - Part 1) with 110 questions in 4 hours, and Domain 2 (Master Plumber - Part 2) with 132 questions in 4 hours.
No. Part 1 and Part 2 are scheduled and paid for separately at $95 each, though passing results remain valid for only one year, so both should be completed within that timeframe.
Part 2 has more questions (132 versus 110) in the same 4-hour window, which tightens the average time per question and makes it the larger content share to prepare for.
Only DSPS-approved bound references and notes are allowed for both parts. Loose paper, removable tabs, sticky notes, paperclips, and practice exams are prohibited, though architect and engineer scale rulers are permitted.
Each part requires a 70% passing score, scored independently - passing Part 1 does not carry over or offset your Part 2 result.