- What This Exam Is, and What the 12 Areas Are
- How the 50 Questions Are Allocated
- The Three Heaviest Areas
- Calculation Areas: Load and Wire Size
- Equipment and Wiring Areas
- Special Occupancies, Installations, Generators and Motors
- Open-Book Mechanics That Shape Your Prep
- Scheduling Your Weeks by Domain
- What Passing Does and Does Not Give You
- Frequently Asked Questions
- The exam has 12 subject areas and 50 questions; the bulletin publishes item counts, not percentage weights.
- Special Installations or Constructions carries the most questions (7); Load Calculations and Supply-Side Service each carry 6.
- Generators other than Dwellings has just 1 question, so it deserves a light but nonzero review.
- Format is open book, four-option multiple choice, two hours, with a cut-score of 70.
What This Exam Is, and What the 12 Areas Are
Electrical Plan Review (2C) is a computer-based, open-book examination built for people who review electrical construction documents against the National Electrical Code. It sits within the NCPCCI program (National Certification Program for Construction Code Inspectors) and is administered today by Prov, either at testing centers or through ExamRoom.AI remote proctoring. The legacy association with the International Association of Electrical Inspectors (IAEI), now doing business as the Independent Alliance of the Electrical Industry, is part of the exam's history, and IAEI still publishes a plan review study guide that explicitly targets this exam. If you are still sorting out terminology, our explainers on what 2C is and what 2C stands for cover the naming in detail.
The twelve headings below are the official written-exam subject areas from the candidate information bulletin. They are descriptions of what gets tested, not a prescribed curriculum, so how you study them is up to you. The bulletin lists both an NEC 2017 form and an NEC 2020 form with identical subject allocations; the 2020 form is the newer one. You may bring other editions of the same reference title, but the specified edition governs the answers, which matters more than most candidates expect.
- Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies
- Calculations of Load
- Calculations of Wire Size
- Conductors and Overcurrent Protection on the Load Side of the Service
- Generators other than Dwellings
- Lighting and Utilization Equipment
- Motors other than Dwellings
- Service Equipment and Conductors on the Supply Side of the Service
- Special Installations or Constructions
- Special Occupancies
- Switches, Disconnects and Controller
- Wiring Methods
Note that Domain 11 uses the singular "Controller" in the source, and we preserve that here. For the broader picture of how this fits with credentials and career paths, see our overview of 2C certification.
How the 50 Questions Are Allocated
The bulletin publishes how many questions come from each area, not what percentage of the exam each represents. We therefore stick to item counts. They total 50 across the twelve domains:
| Domain | Subject Area | Questions |
|---|---|---|
| 1 | Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies | 4 |
| 2 | Calculations of Load | 6 |
| 3 | Calculations of Wire Size | 3 |
| 4 | Conductors and Overcurrent Protection on the Load Side of the Service | 4 |
| 5 | Generators other than Dwellings | 1 |
| 6 | Lighting and Utilization Equipment | 4 |
| 7 | Motors other than Dwellings | 4 |
| 8 | Service Equipment and Conductors on the Supply Side of the Service | 6 |
| 9 | Special Installations or Constructions | 7 |
| 10 | Special Occupancies | 4 |
| 11 | Switches, Disconnects and Controller | 4 |
| 12 | Wiring Methods | 3 |
With a cut-score of 70, the count matters because every question carries real weight on a 50-item test. Spreading effort evenly across all twelve areas is a mistake: three domains account for 19 of the 50 questions, and five domains (Wire Size, Generators, Wiring Methods, plus the smaller blocks) account for very few. Allocate time in proportion to the item counts, then adjust for your own weaknesses. The exact meaning of the cut-score is covered in our passing score breakdown, and if you want a sense of how demanding the test is overall, read how hard the 2C exam is.
The Three Heaviest Areas
Special Installations or Constructions (7), Calculations of Load (6), and Service Equipment and Conductors on the Supply Side of the Service (6) together make up 19 questions, which is 38 percent of the exam by simple arithmetic on the published counts. That is the single best justification for front-loading your preparation here.
Domain 9: Special Installations or Constructions (7 questions)
The largest block, and also the broadest. "Special" in the NEC means chapter 6 style topics where general rules are modified or supplemented. Expect to move quickly between unrelated subjects.
- Learn the structure of the special-installation articles so you can find the right one in seconds with your tabs.
- Practice identifying which article applies from a one-sentence scenario before you attempt the calculation or requirement.
- Pay attention to where a special article overrides a general rule from chapters 1 through 4.
- Mobile-home and park-type installations appear in the bulletin's public sample questions, so they are worth deliberate practice.
Domain 2: Calculations of Load (6 questions)
These are the questions where plan reviewers earn their keep: given a building description, determine the demand load and what it implies for the equipment on the plans.
- Know when the standard method applies versus the optional method for the occupancy type in the question.
- Practice applying demand factors in the correct order; mistakes usually come from sequence errors, not arithmetic.
- Be fluent with the on-screen calculator, including the square root function, which is useful for three-phase work.
- Auditorium lighting branch-circuit calculations appear among the bulletin's public sample items.
Domain 8: Service Equipment and Conductors on the Supply Side of the Service (6 questions)
This domain covers what sits ahead of the main overcurrent device and how the service itself is built and sized.
- Service conductor sizing and the grounding and bonding rules that attach to the service.
- Service neutral load calculations, which appear in the bulletin's public samples.
- Distinguish clearly between supply-side and load-side rules; many wrong answers come from applying the wrong side's requirements.
These three areas also feed each other. A service neutral load question draws on load calculation knowledge, and a service sizing question depends on getting the load right first. Treat them as one connected block of preparation rather than three separate topics.
Calculation Areas: Load and Wire Size
Load (Domain 2) and Wire Size (Domain 3) are neighbors in the outline, but they test different skills. Load calculations determine how much current a system must carry; wire size calculations determine what conductor and protection can safely carry it. Together they are 9 of the 50 questions.
Domain 3: Calculations of Wire Size (3 questions)
Only three questions, but each one typically requires several steps: select a table, apply correction or adjustment factors, then confirm the conductor against terminal temperature ratings and overcurrent protection limits.
- Memorize the logic of the ampacity tables, not the values; you can look the values up.
- Practice questions that stack temperature correction and conductor-count adjustment in the same problem.
- Always verify the final answer against the overcurrent protective device rules, since the "obvious" conductor is sometimes protected incorrectly.
A useful practice rhythm is to work one worked example per day that crosses both domains. For instance, size a mobile-home park feeder (a scenario type the bulletin's public samples include): compute the demand load, select the conductor, then check the protection. That single exercise touches Domains 2, 3, 4, and 9 at once. Our 2C study guide includes more on structuring practice like this.
Equipment and Wiring Areas
The remaining "hardware" domains total 19 questions: Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies (4); Conductors and Overcurrent Protection on the Load Side of the Service (4); Lighting and Utilization Equipment (4); Switches, Disconnects and Controller (4); and Wiring Methods (3). Because they are shorter on calculation and heavier on code lookup, they reward open-book fluency more than raw math.
Domain 1: Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies (4 questions)
Plan reviewers constantly check enclosure and box requirements against the drawings.
- Box fill and conduit body sizing logic.
- Panelboard requirements, including circuit limits, protection, and marking.
- Working space and installation location rules as they relate to what shows on a plan.
Domain 4: Conductors and Overcurrent Protection on the Load Side of the Service (4 questions)
This is the downstream counterpart to Domain 8.
- Feeder and branch-circuit conductor requirements and protection.
- Tap rules and transformer secondary conductor protection.
- Rules that govern when the standard overcurrent device ratings can be rounded up.
Domain 6: Lighting and Utilization Equipment (4 questions)
Covers luminaires, appliances, and other equipment that connect to branch circuits.
- Luminaire installation and supporting requirements.
- Branch-circuit rules for loads such as appliances and fixed electric heating.
- Lighting load questions often overlap with Domain 2 calculations.
Domain 11: Switches, Disconnects and Controller (4 questions)
Where, how, and what rating of disconnecting means a plan must show.
- Disconnect location, rating, and grouping requirements.
- Switch types and their application limits.
- Controller-related requirements that connect to the motor rules in Domain 7.
Domain 12: Wiring Methods (3 questions)
Only three questions, but they reward knowing the chapter 3 structure cold.
- Where each wiring method is permitted or prohibited.
- Support, securing, and protection requirements.
- Raceway fill and bending-related rules as they apply to a given method.
Special Occupancies, Installations, Generators and Motors
Four domains deal with context-specific requirements: Special Occupancies (4), Special Installations or Constructions (7, discussed above), Motors other than Dwellings (4), and Generators other than Dwellings (1).
Domain 10: Special Occupancies (4 questions)
These questions turn on how the building use changes the rules, such as hazardous locations, healthcare, assembly, and similar occupancy-driven requirements.
- Learn to identify the occupancy first, then locate the governing article.
- Understand how special occupancy rules modify the general chapters 1 through 4 requirements.
Domain 7: Motors other than Dwellings (4 questions)
Motor questions are formulaic once you know the process, which makes them a good source of reliable points.
- Conductor sizing from motor full-load current tables rather than nameplate values.
- Branch-circuit short-circuit and ground-fault protection sizing.
- Overload protection and disconnect requirements that link to Domain 11.
Domain 5: Generators other than Dwellings (1 question)
A single question means low expected return per hour studied, but not zero. Read the core generator article once, learn its table of contents, and tab it. Over-investing here costs points elsewhere.
Open-Book Mechanics That Shape Your Prep
Because the exam is open book, the skill being tested is navigation plus judgment, not recall. The administration rules in the bulletin are specific, so confirm them against the current document before test day:
- Format: computer-based, four-option multiple choice, 50 questions in two hours.
- Cut-score: 70. This is the official passing standard, not a candidate pass-rate statistic. No authoritative current pass rate has been verified for this exact exam, and our pass rate article explains what the available data does and does not show.
- References: approved reference books may be highlighted and permanently tabbed before testing, and the applicable NEC Handbook is permitted.
- Calculator: an on-screen calculator is provided and includes square root.
- Fee: USD 130 per attempt, including retakes. A failed exam requires a 30-day wait before retaking. See the cost breakdown for the full pricing picture, including study materials.
- Prerequisites: NCPCCI imposes none to sit the exam, though your employer or jurisdiction may. Details in our requirements guide.
Two hours for 50 questions averages about two and a half minutes per item, but calculation questions in Domains 2, 3, 7, and 8 will eat more than their share. Plan to answer reference-light questions quickly and bank time for the multi-step problems. For scheduling and testing windows, consult our exam dates guide.
Scheduling Your Weeks by Domain
Rather than a generic plan, here is a domain-driven sequence that follows the item counts and the dependencies between areas. Adjust the length to your own timeline.
Calculation foundations
- Domain 2 (Load) and Domain 3 (Wire Size) together, using combined worked examples.
- Set up your calculator workflow, including square root for three-phase problems.
Service and distribution
- Domain 8 (Supply-Side Service) and Domain 4 (Load-Side Conductors and Protection).
- Work a service neutral load problem end to end.
Special installations and occupancies
- Domain 9 (7 questions) and Domain 10, studied as a pair.
- Build the article-finding speed that these domains demand.
Equipment, motors and wiring methods
- Domains 1, 6, 7, 11, and 12, with motors paired to switches and disconnects.
- Light pass over Domain 5 (Generators).
Timed integration
- Full 50-question timed sets with your tabbed books only.
- Review misses by domain and retab your references.
The 2C cheat sheet is a handy companion for the final week, and our practice tests let you drill each of the twelve domains against exam-style questions. Practice most heavily in the areas where the item counts are highest, and use timed full-length practice to test whether your tabbing system actually holds up under the two-hour limit.
What Passing Does and Does Not Give You
Passing the exam demonstrates examination-level competence in electrical plan review. It does not, by itself, grant a local license, certification, or authority to approve plans. Those decisions belong to your jurisdiction or employer. For the practical side of that, see 2C jobs and the discussion of whether it is worth the investment. Salary discussions should be approached carefully: occupation-wide wage data and vendor claims are not specific to this exam, as covered in our salary guide.
One more point about related routes. The ICC reciprocity route for transition to an E3 credential requires both NCPCCI 2B and 2C, plus a current license, supporting score reports, a separate fee, and approval. So 2C alone is insufficient for that application. The separate transition fee listed by ICC as of our October 2026 check was USD 140, and ICC states that certificates more than three years old must meet its own renewal bulletin requirements; that is an ICC transition condition, not a verified renewal rule for NCPCCI 2C itself.
Finally, a caution about search results. Some IAEI pages that surface under 2C-related searches actually describe Canadian CCEI programs, whose exam and renewal rules belong to those separate credentials. Rely on the Prov candidate information bulletin for exam specifics, and treat any page describing Canadian programs as unrelated to this exam.
Frequently Asked Questions
Special Installations or Constructions (Domain 9) has the most, with 7 of the 50 questions. Calculations of Load (Domain 2) and Service Equipment and Conductors on the Supply Side of the Service (Domain 8) follow with 6 each.
No. The bulletin publishes question counts only. The counts in Domain 1 through 12 order are 4, 6, 3, 4, 1, 4, 4, 6, 7, 4, 4, and 3, totaling 50 questions. Any percentages you see elsewhere are derived or unverified.
Yes. Approved reference books may be highlighted and permanently tabbed before testing, and the applicable NEC Handbook is permitted. The edition specified for your exam form governs the answers, even if you bring another edition of the same title.
The exam is 50 four-option multiple-choice questions in two hours, with an official cut-score of 70. The fee is USD 130 per attempt, including retakes, and a 30-day wait applies after a failed attempt.
No. ICC's reciprocity route requires both NCPCCI 2B and 2C, along with a current license, supporting score reports, a separate fee, and approval. Passing 2C alone does not satisfy that application.