- TX-ME Exam Overview: Two Portions, Two Passing Scores
- Eligibility Before You Can Even Schedule
- NEC Knowledge Portion: Domains 1-10
- Calculations Portion: Domains 11-20
- The 2026 NEC Transition and What It Means for You
- Reference Material Rules You Cannot Afford to Miss
- A TX-ME-Specific Study Timeline
- Registration, Fees, and Scheduling Mechanics
- After You Pass: Licensing and Renewal
- Frequently Asked Questions
- The exam has 108 total questions split into NEC Knowledge (75 questions, 150 minutes) and Calculations (33 questions, 170 minutes).
- You must score 70% on each portion separately - a strong Knowledge score cannot offset a weak Calculations score.
- Services and Branch Circuit Conductors tie as the largest Knowledge domains at 11 of 70 scored questions each.
- Exams from September 1, 2026 use the 2026 NEC per the PSI bulletin revised July 9, 2026.
TX-ME Exam Overview: Two Portions, Two Passing Scores
The Texas Master Electrician License Exam, administered by PSI on behalf of the Texas Department of Licensing and Regulation (TDLR), is not one test - it is two separately timed and separately passed portions taken in a single testing appointment. The NEC Knowledge portion administers 75 questions (70 scored, 5 unscored) in 150 minutes. The Calculations portion administers 33 questions (30 scored, 3 unscored) in 170 minutes. Combined, that is 108 questions and 320 minutes of testing time.
The unscored items are seeded throughout each portion and are indistinguishable from scored ones, so every question deserves full attention. Time also does not carry over: if you finish NEC Knowledge in 100 minutes, you cannot bank the remaining 50 minutes for Calculations. Each portion runs on its own clock and requires its own 70% passing score. If you want a deeper breakdown of exactly what "passing" means numerically, see our dedicated TX-ME Passing Score guide.
Eligibility Before You Can Even Schedule
TDLR requires 12,000 hours of supervised on-the-job experience under a Texas-licensed Master Electrician, combined with holding a Journeyman Electrician license for at least two years. A Journeyman Industrial license does not count toward this requirement - a distinction that trips up applicants who worked primarily in industrial settings. Your supervising master must verify the experience, and TDLR must approve your application before you're permitted to test.
Once TDLR receives your application, you have one year to complete all licensing requirements, including passing both exam portions. For the full breakdown of hours, license prerequisites, and documentation, read our TX-ME Requirements guide.
NEC Knowledge Portion: Domains 1-10
The NEC Knowledge portion draws its 70 scored questions from ten subject areas, each with an official allocation. Understanding these weights lets you prioritize study hours where the points actually are, rather than spreading effort evenly across topics that carry very different scoring weight.
| Domain | Subject Area | Scored Questions (of 70) |
|---|---|---|
| 1 | Definitions, Theory, and Plans | 7 |
| 2 | Electrical Services, Service Equipment, and Separately Derived Systems | 11 |
| 3 | Electrical Feeders | 4 |
| 4 | Branch Circuit Conductors | 11 |
| 5 | Electrical Wiring Methods and Electrical Materials | 7 |
| 6 | Electrical Equipment and Devices | 8 |
| 7 | Motors and Generators | 7 |
| 8 | Electrical Control Devices and Disconnecting Means | 3 |
| 9 | Special Occupancies, Equipment, and Conditions | 8 |
| 10 | Renewable Energy Technologies | 4 |
Domain 2 & Domain 4: The Anchor Domains
Electrical Services, Service Equipment, and Separately Derived Systems (Domain 2) and Branch Circuit Conductors (Domain 4) jointly carry the most weight in the Knowledge portion at 11 scored questions each. Together they account for nearly a third of the scored NEC Knowledge exam.
- Service entrance sizing, grounding electrode systems, and separately derived system bonding rules
- Conductor ampacity adjustments, derating for conduit fill and temperature, and conductor protection rules
Domains 8 (Electrical Control Devices and Disconnecting Means) and 3 (Electrical Feeders) carry the lightest scored weight on the Knowledge side, at 3 and 4 questions respectively - still worth reviewing, but not where you should spend disproportionate study time. For a full walkthrough of every domain with study notes, see the TX-ME Exam Domains 2026 guide.
Calculations Portion: Domains 11-20
The Calculations portion reuses many of the same subject names as the Knowledge portion (Domains 12-19 mirror the titles of Domains 2-9), but they are distinct domains testing your ability to apply formulas and NEC tables rather than recall definitions. Domain 11, Calculations and Theory, and Domain 17, Motors and Generators, are unique additions on this side.
| Domain | Subject Area | Scored Questions (of 30) |
|---|---|---|
| 11 | Calculations and Theory | 2 |
| 12 | Electrical Services, Service Equipment, and Separately Derived Systems | 8 |
| 13 | Electrical Feeders | 3 |
| 14 | Branch Circuit Calculations and Conductors | 4 |
| 15 | Electrical Wiring Methods and Electrical Materials | 2 |
| 16 | Electrical Equipment and Devices | 2 |
| 17 | Motors and Generators | 6 |
| 18 | Electrical Control Devices and Disconnecting Means | 1 |
| 19 | Special Occupancies, Equipment, and Conditions | 1 |
| 20 | Renewable Energy Technologies | 1 |
Domain 12: Services (Calculations)
Services, Service Equipment, and Separately Derived Systems is the single largest Calculations domain at 8 of 30 scored questions.
- Standard and optional calculation methods for dwelling services
- Demand factor tables applied to feeder and service load calculations
- Neutral load calculations and unbalanced load reductions
Domain 17: Motors and Generators (Calculations)
At 6 of 30 scored questions, motor calculations are the second-heaviest Calculations domain and frequently the deciding factor between passing and failing this portion.
- Motor branch-circuit conductor sizing using full-load current tables
- Overload and short-circuit protection device sizing
- Multiple-motor feeder calculations
The 2026 NEC Transition and What It Means for You
PSI's exam bulletin, revised July 9, 2026, confirms that examinations administered from September 1, 2026 forward will be based on the 2026 National Electrical Code. This dated transition notice supersedes any residual references to the 2023 code cycle that may still circulate in older study material. If your test date falls on or after September 1, 2026, make sure every code reference, tab set, and practice question you study from is aligned to the 2026 NEC - studying from an outdated code edition is one of the most avoidable ways to fail a portion you were otherwise prepared for.
Check the official PSI candidate bulletin directly before finalizing your study materials, and cross-reference against our TX-ME Exam Dates 2026 guide to confirm which code edition applies to your scheduled test window.
Reference Material Rules You Cannot Afford to Miss
The TX-ME exam is open-book, but "open-book" comes with strict conditions. Only an approved softbound NEC is permitted at the testing center - NEC Handbooks, loose-leaf binders, spiral-bound copies, ring-bound copies, and any added papers are prohibited. Bring the wrong format and you may not be allowed to test.
- Preparation before test day is allowed: notes, highlighting, and underlining written into your code book before the exam are permitted.
- Tabs must be manufacturer-supplied: only permanent NEC-publisher-manufactured or supplied tabs are allowed; homemade tabs added during the test are not permitted, and writing in the reference during testing itself is prohibited.
- Calculators are restricted: a silent, battery-operated, nonprinting, nonprogrammable calculator with no alphabetic capability is permitted - check your calculator's keypad before test day.
- Language options: the computer-based, multiple-choice exam is available in English and Spanish at PSI test centers.
Key Takeaway
Tab your approved softbound NEC in advance using publisher-supplied tabs only, and rehearse locating tables (like Table 310.16 and demand factor tables) under time pressure - you cannot annotate or re-tab during the actual test.
A TX-ME-Specific Study Timeline
Generic study techniques like spaced repetition work, but only when mapped to the actual scored weight of each TX-ME domain. Below is a sample sequencing that front-loads the heaviest-weighted domains on both portions rather than moving through the code book cover to cover.
Heaviest Knowledge Domains
- Domain 2 (Services) and Domain 4 (Branch Circuit Conductors) - 11 questions each
- Build code-lookup speed for grounding, bonding, and conductor sizing tables
Mid-Weight Knowledge Domains
- Domain 6 (Equipment/Devices) and Domain 9 (Special Occupancies) - 8 questions each
- Domain 1 (Definitions, Theory, Plans), Domain 5, and Domain 7 - 7 questions each
Lighter Knowledge Domains + First Calculations Pass
- Domain 3, Domain 10, Domain 8 - lower-weight but still testable
- Introduce Domain 12 (Services, Calculations) - 8 of 30 scored
Calculations Core
- Domain 17 (Motors and Generators) - 6 of 30 scored, heavy formula practice
- Domain 14 (Branch Circuit Calculations) and Domain 13 (Feeders)
Timed Full-Length Simulation
- Simulate both portions under real time limits: 150 minutes for Knowledge, 170 for Calculations
- Practice with your actual tabbed, approved softbound NEC - no substitutions
Use full-length, timed practice tests on our TX-ME practice platform to simulate the 320-minute combined testing experience before test day, and revisit any domain where your simulated score sits below 70%. For a broader look at how challenging candidates generally find each portion, see How Hard Is the TX-ME Exam?.
Registration, Fees, and Scheduling Mechanics
Before you can schedule a testing appointment, TDLR must approve your application - this happens after your $45 license application fee is processed and your supervising master's verification of your 12,000 hours is confirmed. Once approved, PSI charges $78 to take both exam portions in one appointment, or $78 to retake one or both portions if you need to retest.
Because you have one year from TDLR's receipt of your application to complete all requirements, plan your study timeline backward from that deadline rather than treating it as a soft target. Full fee breakdowns, including renewal costs, are covered in our TX-ME Certification Cost 2026 guide.
After You Pass: Licensing and Renewal
Passing both portions doesn't automatically make you licensed forever - the individual Master Electrician license is valid for one year and renews for $45. Each renewal cycle requires four TDLR-approved continuing education hours covering the NEC, Texas law and rules, and NFPA 70E electrical safety.
It's also worth noting that your individual Master Electrician license is separate from an Electrical Contractor business license - passing the TX-ME exam and holding the individual license does not by itself authorize you to operate as a licensed electrical contracting business. If you're evaluating whether pursuing licensure fits your career goals, our ROI analysis and salary guide dig into the practical upside, and TX-ME Jobs covers who typically hires licensed Master Electricians in Texas.
Frequently Asked Questions
Yes. Each portion is scored independently at a 70% threshold. If you pass NEC Knowledge but fail Calculations (or vice versa), you retake only the failed portion, paying the $78 retake fee for that portion.
No. The two portions are separately timed - 150 minutes for NEC Knowledge and 170 minutes for Calculations - and unused time from one cannot transfer to the other.
Per the PSI bulletin revised July 9, 2026, examinations administered from September 1, 2026 onward use the 2026 NEC. Confirm your specific test date against the current bulletin, since this supersedes older 2023 code references.
No. Only an approved softbound NEC is permitted. Handbooks, loose-leaf, spiral-bound, and ring-bound copies, along with any added papers, are prohibited.
No. TDLR requires a Journeyman Electrician license held for at least two years, plus 12,000 supervised hours under a Texas-licensed Master Electrician. A Journeyman Industrial license does not satisfy this requirement.
For a condensed, single-page reference of every fact covered here - fees, timing, domain weights, and reference-material rules - bookmark our TX-ME Cheat Sheet 2026, and revisit this study guide as your primary roadmap while you prepare on our practice test platform.