Trade License Exam Preparation Reference

Why this matters

Most trades require a state or local license to perform work legally. The journeyman exam after the apprenticeship qualifies you to work unsupervised; the master/contractor exam several years later qualifies you to pull permits, run a crew, or own a business. Failing the exam costs a meaningful retest fee plus weeks of work time. Knowing what's on the exam and how to study efficiently is the difference between passing first time and dragging through retests.

Exam structure (typical, varies by state)

Journeyman exam - taken after the apprenticeship hours requirement is met:

  • Trade theory: 60-100 multiple choice questions on code, math, materials, theory
  • Trade practical: sometimes included (NEC tabulation, IPC sizing problems, plan reading)
  • Pass rate: typically 60-75% first attempt
  • Time: 2-4 hours

Master / Contractor exam - taken 3-5+ years after journeyman:

  • Trade portion: deeper code knowledge, project planning
  • Business + law: 30-50 questions on contracts, lien law, insurance, project management, employee rights, OSHA
  • Pass rate: typically 50-65% first attempt
  • Time: 4-6 hours

Continuing education (CE): most states require 4-16 hr/year of continuing education to maintain the license. Code-cycle updates count.

What to study (trade-specific)

Plumbing journeyman / master:

  • IPC (or UPC, depending on state) - the bulk of exam content
  • Plumbing math: pipe sizing, drainage fixture units, slope calculations
  • Fixture installation requirements
  • Backflow prevention
  • Gas piping (where part of the plumbing exam)
  • ADA requirements for plumbing
  • Lien law and contractor business basics (master only)

Electrical journeyman / master:

  • NEC (heaviest content) - the exam is essentially "can you look things up in NEC accurately and quickly"
  • Conductor ampacity, conduit fill, raceway sizing
  • Branch circuit calculations
  • Box fill, voltage drop, motor sizing
  • Specific articles: 110 (general), 210 (branch), 220 (loads), 230 (services), 240 (overcurrent), 250 (grounding), 300 (wiring methods), 310 (conductors), 314 (boxes), 408 (panels), 422 (appliances), 430 (motors), 700 (emergency)
  • Business law (master only)

HVAC journeyman / master:

  • Mechanical code (IMC or UMC)
  • Refrigerant handling (EPA Section 608 cert may be separate)
  • Manual J / Manual S / Manual D fundamentals
  • Fuel gas code (NFPA 54) for gas-fired equipment
  • Combustion air, venting, indoor air quality
  • Business law (master only)

Roofing contractor:

  • IRC roofing requirements
  • ASTM material standards (asphalt shingle, metal roofing)
  • Underlayment, flashing, ventilation
  • Workers' comp, OSHA fall protection
  • Lien law, contract basics

Specialty (Garage door, low-voltage, etc.):

  • Specific industry code or AHJ rules
  • Listed-product knowledge
  • Safety standards (UL 325 for garage doors)

Study materials

Official:

  • Your state's licensing board exam content outline (free, online; this is what's actually on the test)
  • The specific edition of the code book your state has adopted (NEC 2020 vs NEC 2023; IPC 2018 vs 2021)
  • Sometimes a sample test from the licensing board

Commercial:

  • Mike Holt (electrical) - gold standard. Practice exams, study guides, video courses.
  • NASCLA (multi-state contractor business exams)
  • Stewart's Plumbing Code Study (plumbing)
  • PSI / Prometric (the testing companies; sometimes have study materials)
  • Tab books / Tabbed code books (allowed on most open-book exams)

Free / web:

  • Mike Holt Forum, Reddit r/electricians, Plumbing Zone, HVAC Talk - practice questions and discussion
  • YouTube channels (e.g., Electrician U for NEC)
  • Apps with flashcards (Anki decks for code citations)

How to study

Phase 1 - Read the code book (4-8 weeks):

  • Read each article relevant to the exam
  • Highlight (where allowed) and tab (always)
  • Don't memorize numbers; learn what each table contains and where it is

Phase 2 - Practice problems (4-6 weeks):

  • Start with low-difficulty (textbook level) problems
  • Time yourself - exams have time pressure
  • For each missed question, find the answer IN THE CODE BOOK so you build navigation speed
  • Track which question types you miss; focus study there

Phase 3 - Practice exams (2-4 weeks):

  • Full-length, timed
  • Simulate exam conditions (no breaks if the real exam doesn't allow them, only the materials you'll have)
  • After each, review every missed question
  • Take 3-6 practice exams; aim for 85%+ before scheduling the real one

Open-book vs closed-book

Most trade exams are open-book - you bring tabbed code books and reference materials. This sounds easy but is misleading:

  • You have ~1.5 minutes per question
  • If you have to search for every answer, you'll run out of time
  • The point is to test whether you can navigate the code, not whether you've memorized it
  • A well-tabbed code book that you've used in study is faster than an unfamiliar pristine one

Some exams (especially business law portions) are closed-book. Memorize key concepts.

Day-of-exam tips

  • Sleep before, not study. Cramming the night before reduces retention. Last-night study should be light review of weak topics only.
  • Arrive early. Account for traffic and check-in time. The testing centers are strict.
  • Bring required ID and materials. State licensing board's checklist tells you exactly what to bring.
  • Don't bring banned items. Phone, smartwatch - locker required. Sometimes hand-written notes in code books are challenged.
  • Read carefully. Multiple choice questions often have one "obviously right" answer and one "almost right" answer; the difference is a code citation or a definition detail.
  • Mark and move on. Don't spend 5 minutes on one question. Mark it, move forward, return at the end.
  • Use your time. If you finish 30 minutes early, review the marked questions. Don't leave early just because you can.

If you fail

  • Most states allow a retest after 30-60 days
  • Identify what you missed (some states provide a topic breakdown; some don't)
  • Focus retake study on weak areas, not the full curriculum again
  • Many techs pass second attempt with focused study; third attempt is unusual

After you pass

  • License renewal: typically 1-3 year cycles, depending on state. Some require photo update, fingerprints, background check at renewal.
  • CE requirements: plan for 4-16 hours per year of continuing education. Code-cycle update courses count.
  • Insurance and bonding: master / contractor license usually requires general liability insurance and bond posting.
  • Business registration: if you'll be self-employed, register the business with the state and obtain a tax ID.

State-specific differences

References

  • State licensing board websites (the actual exam content outline lives here)
  • Mike Holt Enterprises (electrical exam prep - industry standard)
  • NASCLA (multi-state contractor exam prep)
  • IAPMO (UPC plumbing materials)
  • ICC (IPC plumbing materials)
  • NFPA 70 (NEC) and NFPA 54 (Fuel Gas Code) - the code books themselves