- ACAC does not publish a CETI exam pass rate, so any specific percentage you see online is unverified.
- The passing threshold is at least 75%, per the current Official CETI Application.
- ACAC's December 31, 2025 report lists 3 current CETI certifications, a holder count, not exam volume.
- Retaking costs $100; the initial total is $500 for US/Canada applicants ($525 elsewhere).
Why There Is No Published Pass Rate
If you searched for the CETI pass rate hoping for a tidy percentage, here is the honest answer: the American Council for Accredited Certification (ACAC) does not publish one for the Council-certified Environmental Thermography Investigator credential. Not a rolling figure, not an annual one, not a per-window one. Any site that quotes a precise number is either guessing or borrowing a statistic from a different credential that happens to share the acronym.
That matters because "CETI" is used by several unrelated certifications. The data in this article applies only to the Council-certified Environmental Thermography Investigator credential issued through ACAC, a CESB-accredited program with testing delivered through Kryterion. If you need background on the credential itself before digging into numbers, start with What Is CETI Certification? and What Does CETI Stand For?.
The absence of a published rate is not unusual for small, specialized certification programs. When a credential serves a narrow professional population, the exam cohort in any given year may be too small to produce a statistically meaningful percentage, and many certifying bodies simply choose not to release one.
What the Public Data Actually Shows
There is one hard data point worth discussing, and it is frequently misread. ACAC's Accredited Certification Activity Report, dated December 31, 2025, lists 3 current CETI certifications. That is a count of people currently holding the credential. It is not the number of people who took the exam, it is not the number who passed in 2025, and it cannot be converted into a pass rate.
Here is what you can and cannot infer:
| Data Point | What It Tells You | What It Does Not Tell You |
|---|---|---|
| 3 current certifications (Dec 31, 2025) | The credential is rare; the holder community is very small | How many people attempted the exam or how many failed |
| Passing threshold of at least 75% | The score you need on a closed-book exam | How scores are distributed among candidates |
| Unanimous board approval required | The exam is not the only gate to certification | How often applications are declined or sent back |
| Six-month completion window | Candidates cannot drift through the process indefinitely | How many candidates time out |
The practical takeaway: the small holder count signals a niche credential, but it says nothing about whether the exam itself is brutal or gentle. For a qualitative read on difficulty, see How Hard Is the CETI Exam? Complete Difficulty Guide 2026.
The 75% Standard Explained
The Official CETI Application states that candidates must score at least 75% to pass. For the full breakdown of what that means in practice, see our dedicated page on the CETI passing score. A few points are worth understanding here because they shape how you should think about "pass rate" at all.
Format of the exam
ACAC's general examination policy specifies closed-book, computer-delivered multiple-choice testing, with at least four answer choices per question. Delivery is through test centers or secure online video proctoring. Closed-book is the important phrase: you cannot bring thermal reference charts, emissivity tables or your own field notes into the session. Everything you need must be retrievable from memory.
Why 75% is more demanding than it sounds
A 75% cut score means you can miss roughly one question in four. That sounds forgiving until you consider the content. Thermography questions often test judgment: whether an anomaly pattern indicates moisture intrusion, a missing insulation section, or merely a reflective artifact. Questions built around interpretation punish partial understanding more than recall-based questions do, because several answer choices can look plausible to someone who has only memorized definitions.
Where Candidates Really Get Filtered Out
For most certifications, the exam is the main hurdle. For CETI, a large share of the filtering happens before you ever see a test question. This is the single most important thing to understand if you are trying to estimate your odds.
The eligibility file
ACAC requires two combined years of relevant science-related postsecondary education and field experience, and its eligibility FAQ requires at least one actual year of field experience. You must provide transcripts when claiming education, and verifiable investigation reports or contracts for relevant investigations, consulting or report writing. There is no mandatory training course, which means the application file, not a class completion certificate, is your proof of competence. Full details are in CETI Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Four project sheets
Candidates submit four separate project sheets, along with the online application and email verifications. Each project sheet documents an actual investigation. Sloppy, vague or unverifiable project documentation is a realistic way to stall an application, and the email verifications mean a third party has to confirm your work.
Unanimous board approval
Certification requires unanimous board approval. This is a distinctive feature: passing the exam is necessary but not sufficient. A single dissenting reviewer can stop the process. Candidates who treat the exam as the whole game and rush their application materials are the ones most exposed.
The six-month clock
You must complete the application process, including the examination, within six months. Between gathering transcripts, obtaining verifications and scheduling the exam, that window can tighten quickly. See CETI Exam Dates 2026 for scheduling logistics.
Key Takeaway
Build your project sheets and verification emails first, then schedule the exam. A strong exam score cannot rescue an application file that a board member cannot verify.
What the Four Domains Demand
The issuer's listed application competencies fall under four headings. These are unweighted, and they reproduce ACAC's listed competencies rather than an exhaustive exam blueprint or an official total domain count. ACAC also describes thermal and infrared physics and infrared-camera selection, calibration and operation as part of the scope. The linked candidate handbook page contains no syllabus text, so until ACAC supplies a complete blueprint, this is the limited scope you can responsibly prepare against. For a deeper walk-through, see CETI Exam Domains 2026: Complete Guide to All 4 Content Areas.
Domain 1: Roof inspections
Roofs are where thermography earns much of its reputation, because trapped moisture in roofing assemblies retains heat differently than dry material.
- How solar loading and evening cool-down reveal wet insulation
- Distinguishing true moisture anomalies from surface artifacts such as ballast, patches or reflective membranes
- Conditions that make a roof scan unreliable, including weather and surface state
Domain 2: Building exterior investigations
Exterior scans deal with envelope performance and are heavily influenced by environmental conditions.
- Reading thermal patterns across cladding, windows and wall assemblies
- Accounting for reflections, wind and temperature differential when interpreting images
- Recognizing the limits of an exterior-only view of a wall system
Domain 3: Building interior investigations
Interior work targets insulation gaps, air leakage and moisture behind finished surfaces.
- Identifying missing or settled insulation and thermal bridging
- Separating air-leakage signatures from moisture signatures
- Preparing a space (pressurization, temperature conditions) so findings are meaningful
Domain 4: Plumbing investigations
Plumbing scans look for leaks, concealed supply and drain issues, and radiant systems.
- Tracing hot and cold supply lines and spotting leak-related thermal signatures
- Interpreting what a thermal pattern on a slab or wall implies about concealed piping
- Knowing when thermography is conclusive and when a secondary confirmation method is needed
Underneath all four domains sits the instrument knowledge: thermal and infrared physics, plus camera selection, calibration and operation. Expect questions that require you to reason about emissivity, reflected apparent temperature, spatial resolution and thermal span rather than recite definitions. These concepts are the common thread that makes the exam feel interconnected rather than four separate quizzes.
Fees, Retakes and the Cost of a Miss
Pass rate matters partly because failing has a price. Here is the fee structure from ACAC's published information:
| Item | Amount (USD) |
|---|---|
| Examination fee | $100 |
| Certification fee | $400 |
| Initial total, US/Canada applicants | $500 |
| Official application listing for applicants outside US/Canada | $525 |
| Retake | $100 |
| Renewal | $400 |
The retake fee is modest relative to the whole, which lowers the financial penalty for a first-attempt miss. The larger risk is the six-month completion window: a retake consumes calendar time you may not have. Review the full picture in CETI Certification Cost 2026: Complete Pricing Breakdown.
Staying certified
Certification is valid for two years. The central renewal procedure requires 40 recertification credits (RCs): 10 for continued field activity and 30 hours of professional development. The credential page instead describes 20 professional-development hours annually. ACAC's materials are inconsistent on this point, so confirm directly with ACAC when planning renewal rather than assuming either figure.
Who Sits for This Exam
The candidate pool for a credential like this skews toward working practitioners rather than recent graduates. Typical profiles include building inspectors expanding into infrared diagnostics, forensic and environmental consultants, moisture and mold investigators, energy auditors, roofing consultants and restoration professionals. These are people who already produce investigation reports, which is exactly what the application asks them to submit.
This has a consequence for how you should interpret any informal pass-rate chatter. A self-selected pool of experienced practitioners with documented field work behaves very differently from an open-enrollment pool, and a high or low rate in one context would not transfer to the other. If you are weighing whether the credential fits your career path, see CETI Jobs and Is the CETI Certification Worth It? Complete ROI Analysis 2026.
Sequencing Your Preparation by Domain
Because ACAC has not released a weighted blueprint, avoid over-investing in any single domain. A sensible approach is to build the physics and instrument foundation first, since it supports every domain, then move through the four domains in order of how much of your own field experience you lack.
Physics and camera operation
- Emissivity, reflected temperature, thermal span and level, resolution
- Calibration and camera-selection tradeoffs
Roofs and exteriors
- Solar loading, cool-down timing and moisture signatures
- Envelope interpretation and environmental limits
Interiors and plumbing
- Insulation gaps versus air leakage versus moisture
- Leak signatures and when to confirm with another method
Timed practice
- Closed-book multiple-choice sets across all four domains
- Review every miss against the underlying physics
Spend your weakest domain's time first within each block, and use practice questions that force interpretation rather than recall. Our CETI practice tests are built around exactly that question style, and the CETI Study Guide 2026 and CETI Cheat Sheet 2026 cover the fact-level review. If you want structured instruction rather than self-study, see CETI Training; note that ACAC does not mandate any specific course.
Frequently Asked Questions
ACAC does not publish a pass rate for the Council-certified Environmental Thermography Investigator exam. Any specific percentage you encounter without a primary ACAC source should be treated as unverified. The documented standard is a passing score of at least 75%.
No. ACAC's December 31, 2025 activity report lists 3 current CETI certifications, which is a count of active holders. It does not measure how many people took or passed the exam, so it cannot be used to calculate a pass rate.
You can retake it for a $100 fee. Keep in mind that you must complete the entire application process, including the examination, within six months, so a retake needs to fit inside that window.
No. Certification also requires meeting eligibility standards, submitting four project sheets and email verifications, and receiving unanimous board approval. The exam is one gate among several.
Study the four listed domains (roof inspections, building exterior investigations, building interior investigations and plumbing investigations) plus thermal and infrared physics and camera operation. Treat the scope as limited until ACAC releases a complete blueprint, and prepare broadly rather than betting on any one area.