- How TX-ME Passing Actually Works
- The 70% Threshold on Each Portion
- NEC Knowledge Portion: Domain-by-Domain Scoring
- Calculations Portion: Domain-by-Domain Scoring
- Why You Can't Average the Two Portions
- Fees, Retakes, and the Approval Window
- What FY2025 Results Say About the Score Bar
- Reference Materials and Calculator Rules
- A Domain-Weighted Prep Timeline
- FAQ
- You must score 70% on the NEC Knowledge portion AND 70% on the Calculations portion - separately.
- NEC Knowledge has 70 scored questions (of 75 administered) in 150 minutes; Calculations has 30 scored (of 33) in 170 minutes.
- Services and Branch Circuit Conductors each carry 11 of 70 scored Knowledge questions - the two heaviest domains.
- Services is also the largest Calculations domain at 8 of 30 scored questions.
How TX-ME Passing Actually Works
The Texas Master Electrician License Exam (TX-ME), administered through PSI on behalf of the Texas Department of Licensing and Regulation (TDLR), is not scored as one combined exam. It is two separately timed, separately scored portions: NEC Knowledge and Calculations. Each portion has its own pass/fail outcome, and both must be passed to earn your Master Electrician license.
NEC Knowledge administers 75 questions - 70 scored and 5 unscored - within 150 minutes. Calculations administers 33 questions - 30 scored and 3 unscored - within 170 minutes. Combined administered testing time is 320 minutes, and time cannot be shifted from one portion to the other. If you finish Calculations early, that leftover time does not carry over to NEC Knowledge, and vice versa.
For a deeper breakdown of what each of the 20 content areas actually covers, see the TX-ME Exam Domains 2026: Complete Guide to All 20 Content Areas.
The 70% Threshold on Each Portion
TDLR requires a score of 70% on each portion separately. On NEC Knowledge, that means correctly answering roughly 49 of the 70 scored questions. On Calculations, it means correctly answering roughly 21 of the 30 scored questions. The unscored items - 5 on Knowledge and 3 on Calculations - are mixed in without identification, so you should treat every question on the screen as if it counts.
NEC Knowledge Portion: Domain-by-Domain Scoring
NEC Knowledge draws its 70 scored questions from Domains 1 through 10. The official scored-item allocation is not evenly distributed - some domains carry nearly three times the weight of others.
| Domain | 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 |
Domains 2 & 4: The Two Heaviest Knowledge Areas
Services (Domain 2) and Branch Circuit Conductors (Domain 4) are jointly the largest content areas on NEC Knowledge, each contributing 11 of 70 scored questions - nearly a third of the portion combined.
- Service equipment sizing, grounding/bonding, and separately derived systems rules
- Conductor sizing, ampacity adjustment/correction, and overcurrent protection for branch circuits
- Cross-referencing NEC tables quickly under time pressure, since this is an open-book exam
Calculations Portion: Domain-by-Domain Scoring
Calculations pulls its 30 scored questions from Domains 11 through 20 - the same subject names as the Knowledge portion, but applied through math-based problems rather than code-lookup questions.
| Domain | 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 is the single largest domain on the Calculations portion at 8 of 30 scored questions - over a quarter of the entire portion. Expect load calculations tied to service sizing, demand factors, and service-entrance conductor requirements.
- Practice both dwelling and commercial service load calculations
- Know how demand factors apply to different occupancy types
- Motors and Generators (Domain 17) is the second-heaviest at 6 of 30 - don't neglect motor calculation formulas
Because Domains 12 and 17 together account for nearly half of the scored Calculations questions, candidates who allocate study time evenly across all ten calculation domains often shortchange the two areas that matter most. The TX-ME Exam Domains 2026 guide walks through each domain's typical question style in more depth.
Why You Can't Average the Two Portions
A common misconception is that a strong Knowledge score can offset a weak Calculations score. It can't. Each portion is passed or failed on its own 70% threshold. Scoring 90% on NEC Knowledge and 60% on Calculations still results in a failed exam attempt requiring a retake of the Calculations portion.
Key Takeaway
Prepare for both portions as if they were two separate exams with two separate pass bars. Don't let confidence in NEC Knowledge - an open-book, code-lookup-heavy portion - create a false sense of security about Calculations, which demands active math skill under time pressure.
If you want a candid assessment of which portion trips up more candidates and why, How Hard Is the TX-ME Exam? Complete Difficulty Guide 2026 compares the two portions side by side.
Fees, Retakes, and the Approval Window
Before you can sit for either portion, TDLR must approve your application - this requires a $45 license application fee, plus verification of 12,000 supervised on-the-job hours under a Texas-licensed Master Electrician and at least two years holding a Journeyman Electrician license (a Journeyman Industrial license does not satisfy this requirement). Full eligibility details are covered in TX-ME Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Once approved, PSI charges $78 to take both portions in one sitting. If you fail one or both, the retake fee is also $78, whether you're retaking a single portion or both. Because each portion is scored independently, you only need to retake the portion(s) you failed - but you'll still pay to schedule that session. A complete accounting of every fee in the process, including renewal costs, is in TX-ME Certification Cost 2026: Complete Pricing Breakdown.
What FY2025 Results Say About the Score Bar
TDLR's official FY2025 examination-result data shows a 22.21% pass rate on Master NEC (771 passes among 3,472 completed examinations) and a 19.08% pass rate on Master Calculations (753 passes among 3,946 completed examinations). These figures are historical portion-level results predating the 2026 code transition, and they are not first-attempt or combined-candidate rates - but they make one thing clear: a fixed 70% cutoff on each portion is a genuinely difficult bar to clear, not a formality.
For more context on how these numbers should shape your prep intensity, read TX-ME Pass Rate 2026: What the Data Shows.
Reference Materials and Calculator Rules
The TX-ME is open-book, but only in a specific way that affects how efficiently you can hit the 70% marks. You may bring an approved softbound NEC - NEC Handbooks, loose-leaf, spiral or ring-bound copies, and any added papers are prohibited. Notes, highlighting, and underlining prepared before test day are allowed, and tabs must be permanent, NEC-publisher-manufactured or supplied tabs. You cannot write in your reference during the actual test session.
A silent, battery-operated, nonprinting, nonprogrammable calculator without alphabetic capability is permitted - critical for the Calculations portion's 170-minute window. Because the PSI bulletin revised July 9, 2026 requires the 2026 NEC for examinations from September 1, 2026, make sure your softbound code book, tabs, and annotations are built around the correct edition before test day.
A Domain-Weighted Prep Timeline
Rather than studying all 20 domains equally, allocate time in proportion to their scored-question weight. This timeline assumes you've already confirmed TDLR approval and are focused purely on the exam content.
High-Weight Knowledge Domains
- Services (Domain 2) and Branch Circuit Conductors (Domain 4) - 11 scored questions each
- Build and index your NEC tabs around these two domains first
Mid-Weight Knowledge Domains
- Equipment and Devices, Special Occupancies (8 scored questions each)
- Definitions/Theory/Plans, Wiring Methods, Motors and Generators (7 each)
High-Weight Calculations Domains
- Services calculations (Domain 12) - 8 scored questions, largest on this portion
- Motors and Generators calculations (Domain 17) - 6 scored questions
- Practice under the calculator restrictions you'll actually use on test day
Timed Full Simulations
- Run full 150-minute and 170-minute timed sessions separately, since time can't transfer between portions
- Review misses by domain to see if you're below 70% pace anywhere
For a structured, week-by-week plan built entirely around this exam's format, see the TX-ME Study Guide 2026: How to Pass on Your First Attempt. If you want a condensed reference of the highest-yield facts to review the night before, the TX-ME Cheat Sheet 2026 covers the essentials in one page. You can also run through full-length TX-ME practice tests that mirror the real question distribution across all 20 domains before locking in your exam date.
Frequently Asked Questions
You need 70% on the NEC Knowledge portion and 70% on the Calculations portion, scored separately. Passing one portion does not carry over or compensate for failing the other.
NEC Knowledge has 70 scored questions, so 70% is roughly 49 correct. Calculations has 30 scored questions, so 70% is roughly 21 correct. Unscored items (5 on Knowledge, 3 on Calculations) don't count toward this but aren't identified during the test.
No. Because each portion is scored independently, you only need to retake the portion(s) you failed. PSI's $78 retake fee applies whether you retake one portion or both.
On NEC Knowledge, prioritize Services and Branch Circuit Conductors (11 scored questions each). On Calculations, prioritize Services calculations (8 scored questions) and Motors and Generators calculations (6 scored questions).
The passing score itself - 70% per portion - is unaffected. However, the PSI bulletin revised July 9, 2026 requires the 2026 NEC for exams administered from September 1, 2026, so make sure your softbound code book and tabs match the correct edition before test day.