The Texas Master Electrician Guide

What Is the Texas Master Electrician License?

The master electrician license verifies that an electrician can design, install, alter and repair electrical systems in full compliance with the National Electrical Code (NEC) — and can take responsibility for that work. In Texas, the license is regulated by TDLR and the exam is administered at PSI computer-based testing centers. It is the top of the field-license ladder: the license that lets you supervise journeymen and apprentices, sign off on work, pull permits in your own name, and run an electrical contracting business.

You are already a licensed electrician — this is the step from journeyman to master, from working under someone else's license to holding your own. The hours you documented on the way to your journeyman license form the foundation of the master application, and the exam assumes journeyman-level command of the code before it tests the master-level judgment on top.

Eligibility: 2 Years as a Journeyman + 12,000 Hours

Texas does not let you walk into the master exam. TDLR requires documented field experience at journeyman level before you can even schedule:

• Journeyman license: you must have held a journeyman electrician license for at least 2 years.
• On-the-job training: you must document 12,000 hours of on-the-job training performed under the supervision of a Texas-licensed master electrician, who attests to the work.
• Documentation: keep a running log of dates, hours, job types and tasks. TDLR reviews this documentation when you apply.
• Application: submit the TDLR master application with your experience records and the applicable fee, then await your eligibility notice before scheduling the exam with PSI.

Exam Format: Two Separately-Scored Portions, Open Book

The Texas Master Electrician exam is open book and split into two portions that are scored independently — you can pass one portion and fail the other, and you only retake the portion you failed. Both portions run against the NEC 2026:

• NEC Knowledge (TX-MST-KNOW) — 75 items, 150 minutes: 70 scored questions plus 5 unscored pretest items. Tests code administration, wiring and protection, wiring methods, equipment, motors, special occupancies and renewable energy — the “where is it in the code” portion. Pass line: 70%.
• Calculations (TX-MST-CALC) — 33 items, 170 minutes: 30 scored questions plus 3 unscored pretest items. Tests service and feeder calculations, branch circuits, ampacity, wiring methods math, motors and the Chapter 9 tables. Pass line: 70%.

The open-book rules matter as much as the content. You bring a soft-bound NEC 2026; it may be highlighted and tabbed, but only manufacturer tabs are permitted. Unless a question states otherwise, all conductors are considered copper. Because the code is in your hands, the exam does not reward memorization — it rewards knowing which chapter covers which topic, using the index efficiently, and reading sections with their exceptions and tables.

NEC Knowledge Subject Areas (TX-MST-KNOW)

TDLR publishes the subject-area weights for the 70 scored items. Study time should track these weights:

The pattern is clear: Services/Service Equipment/SDS (11) and Branch Circuit Conductors (11) together account for nearly a third of the scored items. Renewable Energy and Control Devices are tested, but lightly — master the heavy columns first.

Calculations Subject Areas (TX-MST-CALC)

On the Calculations portion, Services & SDS (8) and Motors & Generators (6) are the load-bearing subjects — together they are nearly half the scored items. That is where most calculation reps should go.

Fees, Retakes & Pass Rates

• Fee: $78 for both portions of the exam.
• Retakes: $78 per failed portion. Because each portion is scored separately, you only re-sit the portion you failed — a retake machine, not a full-exam reset.
• Volume & pass rate: TDLR reported roughly 7,400 master exam attempts per year (2025) with a pass rate of about 19–22%. Most candidates do not clear both portions on the first try.
• Vendor: exams are delivered by PSI (test-takers.psiexams.com/tdlnrp) after TDLR confirms eligibility.

A 19–22% pass rate is not a warning to skip the exam — it is a warning to prepare like the exam is scored: against the official subject-area weights, with the code open, under full-length timed conditions, until 70% is routine rather than aspirational.

How to Prepare

1. Confirm your TDLR eligibility. Verify your journeyman license tenure (2+ years) and 12,000 documented hours under a Texas-licensed master before you invest in exam prep.
2. Get the soft-bound NEC 2026. Buy the edition named in the exam bulletin. Tab the chapters and the most-used tables — ampacity tables, the service/feeder sections, the Chapter 9 conduit and box-fill tables. Manufacturer tabs only.
3. Learn the chapter map. Know where each topic lives — grounding in Article 250, services in 230, feeders in 215, branch circuits in 210 — before you open a practice question.
4. Drill the heavy columns first. Services/SDS and Branch Circuits on NEC Knowledge; Services/SDS and Motors on Calculations. Get those areas to exam-day speed before touching Renewable Energy or Control Devices.
5. Practice calculations separately. Service and feeder loads, ampacity adjustments, motor calcs and conduit fill need dedicated reps — they carry their own scored portion.
6. Simulate under exam conditions. Full-length, timed, open-book runs of both portions (75 items/150 min and 33 items/170 min) at least once a week in the final month, aiming past the 70% line.

Master Electrician Practice is built for this exact exam: both master portions (TX-MST-KNOW and TX-MST-CALC) with code-referenced questions aligned to the TDLR blueprint, timed simulations, full open-book NEC 2026 theory and an AI tutor. Start with free practice questions to feel the format before you commit.

Frequently Asked Questions

Ready to Become the Boss?

The master license is the difference between working under someone's license and holding the one that signs the permits. Start with the official blueprint: learn the code with our Master Electrician NEC theory guides, try free Texas Master practice questions, and see the all-inclusive pricing — one bundle covering both exam lines, so you never buy trade and calculations prep separately.