- Why the Two-Part Format Makes TX-ME Hard
- What the Pass Rate Numbers Actually Tell You
- NEC Knowledge Portion: The 10 Domains That Decide Your Score
- Calculations Portion: Why 170 Minutes Isn't as Generous as It Sounds
- The Open-Book Trap Most Candidates Underestimate
- The Hardest Part Might Be Getting to the Testing Center
- What a Failed Attempt Actually Costs You
- Sequencing Your Prep Around the Hard Domains
- Frequently Asked Questions
- TX-ME is two separately timed, separately scored portions: NEC Knowledge (75 questions, 150 minutes) and Calculations (33 questions, 170 minutes).
- You need 70% on each portion independently - a strong Knowledge score cannot offset a weak Calculations score.
- FY2025 TDLR data shows 22.21% passed Master NEC and 19.08% passed Master Calculations, reflecting how demanding both portions are.
- Eligibility itself is a barrier: 12,000 supervised hours plus two years holding a Journeyman Electrician license (not Journeyman Industrial).
Why the Two-Part Format Makes TX-ME Hard
The Texas Master Electrician License Exam isn't one long test - it's two exams administered back-to-back under one appointment. TDLR and PSI structure it as 108 total administered questions: 75 on the NEC Knowledge portion (70 scored, 5 unscored) in 150 minutes, and 33 on the Calculations portion (30 scored, 3 unscored) in 170 minutes. Combined, that's 320 minutes of testing time, but here's the detail that trips people up: unused time cannot transfer between portions. If you finish Knowledge in 100 minutes, those extra 50 minutes are gone - you can't apply them to Calculations.
That separation is also how the exam is scored. You must hit 70% independently on NEC Knowledge and 70% independently on Calculations. A candidate who scores 95% on Knowledge but 65% on Calculations still fails the exam overall and typically must retake the failed portion. This dual-hurdle design is one of the biggest reasons TX-ME has a reputation for difficulty - you're not studying for one passing threshold, you're studying for two, and they test genuinely different skill sets: code lookup and comprehension versus applied math under the NEC.
What the Pass Rate Numbers Actually Tell You
TDLR's official FY2025 examination-result statistics put Master NEC at a 22.21% pass rate (771 passes out of 3,472 completed examinations) and Master Calculations at 19.08% (753 passes out of 3,946 completed examinations). These are portion-level completion statistics - not first-attempt rates and not a combined pass rate for candidates who cleared both portions in the same sitting. Even read cautiously, the numbers make one thing clear: most completed attempts on either portion did not result in a pass that testing year.
It's worth noting these figures predate the 2026 NEC code transition. The PSI bulletin revised July 9, 2026 requires the 2026 NEC for examinations administered from September 1, 2026 onward, so candidates testing under the new code cycle are working from updated code references and numbering. If you want a deeper breakdown of how these statistics are calculated and what they mean for your own odds, see TX-ME Pass Rate 2026: What the Data Shows.
Key Takeaway
Don't treat "70% to pass" as a low bar. The published portion-level pass rates suggest most completed exam attempts fall short of that threshold, so treat every domain as scoring-relevant, not just the ones you find intuitive.
NEC Knowledge Portion: The 10 Domains That Decide Your Score
The NEC Knowledge portion draws its 70 scored questions from ten subject domains, and the allocation is not even. Two domains - Electrical Services, Service Equipment, and Separately Derived Systems, and Branch Circuit Conductors - are tied as the largest, each contributing 11 of the 70 scored questions. Together they represent nearly a third of the scored Knowledge portion.
Domain 2: Electrical Services, Service Equipment, and Separately Derived Systems (11/70)
Candidates need fluency in service sizing, service equipment rules, and how separately derived systems are bonded and grounded - this is the single most heavily weighted knowledge area alongside Domain 4.
- Service entrance conductor sizing and clearance requirements
- Grounding and bonding rules for separately derived systems
- Disconnecting means requirements at the service
Domain 4: Branch Circuit Conductors (11/70)
This domain covers conductor sizing, ampacity adjustments, and the rules governing branch circuit design - a favorite area for scenario-style questions that combine multiple NEC tables.
- Conductor ampacity and derating factors
- Branch circuit rating and load calculations tied to conductor selection
- Overcurrent protection coordination with conductor size
The remaining scored allocation runs: Definitions, Theory, and Plans (7), Electrical Feeders (4), Electrical Wiring Methods and Electrical Materials (7), Electrical Equipment and Devices (8), Motors and Generators (7), Electrical Control Devices and Disconnecting Means (3), Special Occupancies, Equipment, and Conditions (8), and Renewable Energy Technologies (4). Special Occupancies and Electrical Equipment and Devices are both mid-weight domains worth real study time even though they don't top the list. For a full domain-by-domain breakdown with study priorities across all 20 domains, see TX-ME Exam Domains 2026: Complete Guide to All 20 Content Areas.
Calculations Portion: Why 170 Minutes Isn't as Generous as It Sounds
The Calculations portion has fewer scored questions - 30 out of 33 administered - but it runs longer (170 minutes) because each question typically requires working through NEC tables and formulas rather than recalling a rule. The domain names mirror the Knowledge portion's structure but the content is applied math: sizing, loads, and derating rather than definitions.
Services is the single largest Calculations domain at 8 of 30 scored questions, followed by Electrical Control Devices and Disconnecting Means and Motors and Generators, each weighted at 6 and... actually here the official allocation runs Calculations and Theory (2), Services (8), Feeders (3), Branch Circuit Calculations and Conductors (4), Wiring Methods and Electrical Materials (2), Electrical Equipment and Devices (2), Motors and Generators (6), Electrical Control Devices and Disconnecting Means (1), Special Occupancies, Equipment, and Conditions (1), and Renewable Energy Technologies (1).
Domain 12: Electrical Services, Service Equipment, and Separately Derived Systems (8/30)
This is the highest-weighted Calculations domain by a wide margin - a quarter of the scored questions on this portion. Expect multi-step service load calculations that require careful table lookups under time pressure.
- Standard and optional service load calculation methods
- Demand factor application across dwelling and commercial services
- Service-derived system sizing scenarios
Domain 17: Motors and Generators (6/30)
Motor calculations - full-load current, branch circuit sizing, and overload protection - form the second-largest chunk of the Calculations portion, so time spent here compounds directly into score.
- Motor branch circuit conductor and short-circuit protection sizing
- Full-load current table lookups and multiple-motor circuits
Because both Services domains (Domain 2 in Knowledge and Domain 12 in Calculations) are the heaviest-weighted content in their respective portions, mastering service calculations pays off twice. This is exactly the kind of cross-portion pattern the TX-ME Study Guide 2026: How to Pass on Your First Attempt walks through in more sequencing detail.
| Feature | NEC Knowledge Portion | Calculations Portion |
|---|---|---|
| Administered questions | 75 | 33 |
| Scored / unscored | 70 scored, 5 unscored | 30 scored, 3 unscored |
| Time allotted | 150 minutes | 170 minutes |
| Passing threshold | 70%, scored separately | 70%, scored separately |
| Largest domain(s) | Services & Branch Circuit Conductors (11/70 each) | Services (8/30) |
| FY2025 pass rate (TDLR data) | 22.21% (771/3,472) | 19.08% (753/3,946) |
The Open-Book Trap Most Candidates Underestimate
TX-ME is open-book, which sounds like it should make the exam easier. In practice, it's one of the reasons candidates underprepare. You're allowed an approved softbound NEC - not the NEC Handbook, not loose-leaf, spiral, or ring-bound versions, and no added papers. Tabs must be permanent, publisher-manufactured or publisher-supplied tabs; you cannot write in the code book during the test, though notes, highlighting, and underlining prepared before test day are permitted.
The trap: with 150 minutes for 75 questions and 170 minutes for 33 questions, you don't have time to look up every answer from scratch. Successful candidates use the open-book format to verify, not to learn on the fly. If you're flipping through an unfamiliar table structure during the exam, you've already lost the time advantage the open-book format was supposed to give you. A silent, battery-operated, nonprinting, nonprogrammable calculator without alphabetic capability is permitted for the math-heavy Calculations portion - bring one you've actually practiced with.
The Hardest Part Might Be Getting to the Testing Center
Difficulty conversations about TX-ME usually focus on the exam content, but the eligibility path is arguably the bigger filter. Applicants need 12,000 supervised on-the-job hours under a Texas-licensed Master Electrician, plus a Journeyman Electrician license held for at least two years. A Journeyman Industrial license does not satisfy this requirement - a distinction that catches applicants off guard. Supervising masters must verify the hours, and TDLR approval is required before you can even schedule a test date.
There's also a clock running once you apply: licensing requirements must be completed within one year after TDLR receives the application. That means the 12,000-hour requirement and license verification need to be locked in well before you submit, not worked out afterward. For the complete breakdown of hours, license prerequisites, and verification steps, see TX-ME Requirements 2026: Eligibility, Prerequisites & How to Qualify.
What a Failed Attempt Actually Costs You
Beyond the $45 TDLR license application fee, PSI charges $78 to sit for both portions, and $78 again to retake one or both portions if you don't clear the 70% threshold on the first try. Because the two portions are scored independently, a retake fee applies even if you only failed one side of the exam - Knowledge or Calculations. That's the financial argument for treating both portions with equal seriousness rather than leaning on the one that feels more comfortable.
Once licensed, the individual Master Electrician license is valid for one year and renews for $45, with four TDLR-approved continuing education hours required each cycle covering the NEC, Texas law and rules, and NFPA 70E electrical safety. That's a separate, ongoing commitment from the individual license - and distinct from the Electrical Contractor business license, which is its own credential entirely. For a full cost breakdown across application, testing, retakes, and renewal, see TX-ME Certification Cost 2026: Complete Pricing Breakdown.
Sequencing Your Prep Around the Hard Domains
Generic study techniques only matter if you point them at the right targets. Given that Services (Domains 2 and 12), Branch Circuit Conductors (Domain 4), and Motors and Generators (Domains 7 and 17) carry the heaviest scored weight across both portions, your prep calendar should front-load those areas rather than moving through the NEC cover to cover in article order.
Services and Branch Circuit Fundamentals
- Drill service sizing and grounding/bonding rules (Domain 2) alongside branch circuit conductor sizing (Domain 4) - the two largest Knowledge domains
- Practice locating these tables quickly in your approved NEC to build open-book speed
Calculations Heavy Hitters
- Work full service load calculations repeatedly (Domain 12, 8/30 scored) using both standard and optional methods
- Move into motor branch circuit and overload calculations (Domain 17, 6/30 scored)
Mid-Weight Domains and Timed Practice
- Cover Electrical Equipment and Devices, Special Occupancies, and Motors and Generators (Knowledge side) at 7-8 scored questions each
- Run full-length timed practice sessions respecting the 150- and 170-minute limits separately, since time cannot transfer between portions
For a structured week-by-week plan with more detail on pacing and review cycles, the TX-ME Study Guide 2026: How to Pass on Your First Attempt expands on this approach, and the TX-ME Cheat Sheet 2026: One-Page Review of Must-Know Facts is useful for rapid final review before test day. You can also run realistic timed sessions on our TX-ME practice tests to get a feel for pacing on both portions before you sit for the real exam.
Frequently Asked Questions
TX-ME adds a dedicated Calculations portion scored separately from NEC Knowledge, plus a 12,000-hour supervised experience requirement and a two-year Journeyman license prerequisite - layers of difficulty beyond content alone.
Both portions are administered in the same appointment, but each is timed and scored separately at 70%. If you fail one portion, PSI's $78 retake fee applies to retesting on the failed portion(s).
Focus on Services (heaviest domain in both portions), Branch Circuit Conductors, and Motors and Generators - these carry the largest scored-question allocations across the 20 domains.
No. Only an approved softbound NEC is allowed; handbooks, loose-leaf, spiral, and ring-bound versions along with added papers are prohibited at PSI test centers.
Yes - the PSI bulletin revised July 9, 2026 requires the 2026 NEC for exams from September 1, 2026 onward, so candidates testing after that date should study the updated code rather than relying on older references.