- What "Pass Rate" Actually Means for the AI Commission Exam
- What Data Is (and Isn't) Published
- Why a Single Pass-Rate Figure Would Mislead
- The Exam Structure Behind the Numbers
- Where Candidates Lose Points: A Domain-by-Domain Read
- Sequencing Your Prep Around the Twelve Domains
- Who Sponsors Candidates and Why It Shapes Outcomes
- Frequently Asked Questions
- The National Board does not publish a verified pass rate for the Authorized Inspector Commission exam, so any specific percentage you see online is unverified.
- The exam has 85 questions and requires attending the AI Commission course along with a passing examination.
- The detailed NB-331-NC outline has 12 headings, and no percentage weights are published for them.
- Required references include ASME Sections I, IV, V, VIII Division 1 and IX, B31.1, QAI-1 and RCI-1/NB-263.
What "Pass Rate" Actually Means for the AI Commission Exam
Searching for an "AI pass rate" can be frustrating, and it helps to be precise about what is being measured. On this site, AI means the National Board Authorized Inspector Commission, issued through The National Board of Boiler and Pressure Vessel Inspectors. It is a credential for inspectors who verify that boilers and pressure vessels are designed, fabricated, tested and documented in accordance with the ASME Boiler and Pressure Vessel Code. It has nothing to do with the many other credentials that share the same two letters, and pass-rate figures quoted for those exams do not transfer here.
That distinction matters because a casual search will surface percentages and statistics that belong to unrelated certifications. Importing those numbers into your expectations about the Commission exam would give you a false picture. This article sticks to what can be supported about the National Board credential and is candid about what cannot.
What Data Is (and Isn't) Published
The honest summary: the issuer's examination information confirms the structure of the process, but a verified, current pass-rate percentage is not part of what is confirmed here. Here is what can be stated with confidence.
| Item | Status |
|---|---|
| Number of exam questions | 85 questions, per the issuer's examination information |
| Course attendance | Attendance at the AI Commission course is part of the pathway |
| Passing requirement | A passing examination is required |
| Content outline | NB-331-NC Revision 6, 12 numbered headings |
| Percentage domain weights | Not published |
| Exact exam timer | Unverified here; confirm with the National Board |
| Current exam fee | Unverified here; confirm with the National Board |
| Numerical pass mark | Unverified here; confirm with the National Board |
| Historical pass-rate percentage | No verified figure available |
If you want the latest on cut scores, our guide to the AI passing score walks through what is and isn't known about how the exam is graded, and the AI certification cost breakdown covers the fee components you should verify directly before budgeting.
Why a Single Pass-Rate Figure Would Mislead
Even if a pass rate were published, it would be a weak predictor of your own result, and the reasons are specific to how this credential works.
The candidate pool is not a random sample
Most people who sit this exam are not walking in cold. The pathway includes attending the AI Commission course, and candidates are typically working in or being sponsored toward the inspection field. Their baseline familiarity with pressure equipment, shop practices and code language is far above that of the general public. A pass rate drawn from that pool tells you how well prepared, motivated and employer-supported candidates perform, not how hard the content is for you specifically.
The exam is open-reference in spirit, not memory-based
The required reference list is long: ASME Sections I, IV, V, VIII Division 1 and IX, B31.1, QAI-1 and RCI-1/NB-263. The skill being tested is the ability to find, interpret and apply code rules correctly. Two candidates with identical knowledge can score very differently depending on how fast they navigate the books. That variability makes an aggregate percentage even less informative.
The pass mark is not confirmed here
Without a verified numerical pass mark, you cannot translate a pass rate into a target score. What you can do is aim for consistent accuracy across all twelve areas, because no percentage weights are published to tell you which areas you can afford to neglect.
The Exam Structure Behind the Numbers
The detailed outline in NB-331-NC Revision 6 has 12 numbered headings. The shorter introductory summary groups the content into 11 objectives, but that summary does not replace the detailed hierarchy, so build your preparation around the 12-heading version. The exam itself contains 85 questions.
Because the content is code-driven, expect questions that present a situation (a construction detail, a weld, a material condition, a documentation scenario) and ask what the applicable rule requires or who is responsible for an action. For a full walkthrough of each area, see our complete guide to all 12 AI exam content areas.
Key Takeaway
Use the 12-heading detailed outline, not the 11-objective summary, as your master checklist. Tab your code books to match each heading so that every topic has a known home in your references.
Where Candidates Lose Points: A Domain-by-Domain Read
Since no official data breaks results down by domain, the following is a qualitative reading of where the content is dense, technical or easy to confuse. Treat it as a planning aid, not a statistical claim.
Domain 1: Responsibilities and Duties of the AI
This domain covers the RCI-1/ASME QAI-1 roles of authorized inspection agencies, supervisors and inspectors, plus duties that appear throughout the required references.
- Know who does what: inspector, supervisor, agency and manufacturer responsibilities are distinct.
- Duties are scattered across multiple documents, so a question may require pulling from more than one source.
Domains 2 and 3: Types and Terminology; Code Structure and Content
These are the foundation. You must identify boiler and vessel types and parts, then navigate the ASME BPVC structure and related requirements.
- Terminology errors cascade into wrong answers elsewhere, so settle vocabulary early.
- Understanding which section governs which equipment is the key to fast, accurate look-ups.
Domain 4: Quality Control System
Draws on Section I Appendix A-301, Section IV Appendix F and Section VIII Division 1 Appendix 10.
- Candidates often study the three appendices in isolation; compare them side by side instead.
- Know what a manufacturer's quality control system must contain for each construction type.
Domain 5: Design
Likely the broadest technical area, spanning power and heating boilers, external piping and vessels.
- Shells and drums, piping, headers and nozzles, formed and flat heads, braced and stayed surfaces.
- Weld sizes, nozzle reinforcement, preformed and prefabricated pressure parts, flanges.
- Joint efficiencies and ligament efficiency, both of which involve applying rules rather than recalling facts.
Domain 6: Materials
Construction-section rules, product-form tolerances, markings and methods, pressure and nonpressure parts, non-ASME standards, defective-material repair and certifications.
- Distinguish pressure parts from nonpressure parts, since the rules differ.
- Understand when material certifications are required and what they must show.
Domain 7: Fabrication
A heavy domain covering cutting and edge preparation, cold-forming limits, out-of-roundness limits for cylindrical, conical and spherical shells, formed-head tolerances, and attachment of lugs and fittings.
- Holes for screwed and threaded stays and tubes.
- Welding responsibilities and processes, procedure and welder or operator qualifications under Section IX.
- Surface cleaning, alignment tolerances, spin holes, finished joints, fillet welds, defect repair, peening and surface weld-metal buildup.
Domain 8: Nondestructive Examination
When NDE is required, which methods are permitted, the advantages and limitations of each method, procedure and personnel qualification, and reports.
- Pair Section V with the construction section to determine when examination is mandated.
- Be ready to judge whether a method suits a given flaw type.
Domain 9: Testing and Heat Treatment
Impact testing, heat treatment and pressure tests, including exemptions and alternatives.
- Exemptions and alternatives are fertile ground for tricky questions, since the default rule is not always the one that applies.
Domains 10, 11 and 12: Calibration; Data Reports and Stamping; Record Retention
The administrative end of the process, but not trivial. Calibration covers frequencies, methods, tolerances, master standards, identification and records for working and master measurement and test equipment. Data reports and stamping are specific to construction type, and record retention is governed by ASME Sections I, IV and VIII.
- Candidates sometimes under-study these because they feel like paperwork; with no published weights, that is a risk.
- Learn the differences in retention and reporting requirements between construction types.
Sequencing Your Prep Around the Twelve Domains
Rather than a generic schedule, order your study by dependency: vocabulary and Code navigation first, then technical construction rules, then documentation. This is one possible arrangement; adjust it to your course dates and work schedule.
Foundations and Navigation
- Domains 1, 2 and 3: roles, equipment terminology and Code structure.
- Tab and index every required reference so look-ups become automatic.
Design and Materials
- Domains 4, 5 and 6: quality control appendices, design rules, material requirements.
- Work calculation-style problems on joint efficiency, nozzle reinforcement and ligament efficiency.
Fabrication, NDE and Testing
- Domains 7, 8 and 9: tolerances, welding qualification, examination methods, heat treatment and pressure tests.
Documentation and Full Review
- Domains 10, 11 and 12: calibration, data reports, stamping and record retention.
- Take timed practice sets covering all twelve headings using the AI Exam Prep practice tests.
For a broader plan that includes how to use the AI Commission course alongside your own study, see the AI study guide, and keep the AI cheat sheet handy for last-minute review of high-yield facts.
Who Sponsors Candidates and Why It Shapes Outcomes
The Authorized Inspector Commission is tied to the authorized inspection agencies named in RCI-1 and QAI-1. In practice, candidates are generally connected to the inspection ecosystem: authorized inspection agencies, and organizations that need qualified inspectors for boiler and pressure vessel construction and in-service oversight. Because the role involves independent verification of code compliance, hiring and sponsorship tend to be closely linked to meeting the pathway's requirements.
This sponsorship dynamic is one more reason an overall pass rate is a blunt instrument. Candidates with employer backing often have access to mentors, shop exposure and code libraries. If you are exploring whether that investment makes sense for your career, our analysis of whether the AI certification is worth it and the overview of AI requirements and eligibility are good next reads. For compensation context, see the AI salary guide.
Key Takeaway
Stop chasing a pass-rate percentage and start measuring your own readiness. Score yourself domain by domain on realistic code-based questions, and do not sit the exam until your weakest heading is as solid as your strongest.
Frequently Asked Questions
A verified pass-rate percentage is not available from the sources used for this article. The issuer's examination information confirms 85 questions and the requirement of attending the AI Commission course with a passing examination, but does not provide a confirmed pass rate here. Contact the National Board for any official statistics.
The issuer's examination information confirms 85 questions. The exact timer, current fee and numerical pass mark are not verified here, so confirm them directly with the National Board before you schedule.
No percentage weights are published for the 12 headings in the detailed NB-331-NC Revision 6 outline. Because of that, plan to study every heading rather than concentrating on a few. Our domains guide describes each area in detail.
The required references are ASME Sections I, IV, V, VIII Division 1 and IX, B31.1, QAI-1, and RCI-1/NB-263. Success depends heavily on being able to navigate these documents efficiently and apply their rules to specific situations.
The difficulty comes mainly from breadth and technical detail rather than from any single topic, since the outline spans design, materials, fabrication, examination, testing, calibration and documentation. Read our difficulty guide and test yourself with the practice exams to gauge your readiness.