- 125 multiple-choice questions, 4 hours 15 minutes, plus a separate 10-minute break - closed book.
- Conducting Commissioning Activities (24%) and Existing Building Commissioning (23%) make up nearly half the exam.
- Application fees run $350-$400 for Certified Member-company employees, $2,500 for everyone else.
- Reported 2025 pass rate was 58% - 84 passes among 145 approved candidates.
Exam Snapshot: The Numbers You Need
If you only have ten minutes before closing your laptop tonight, this is the section to read. The Certified Commissioning Authority (CxA) credential is administered through AABC Commissioning Group (ACG) and its ACG Certification Council, and every number below is specific to that program - not to any other credential that happens to share the "CxA" initials.
| Fact | Detail |
|---|---|
| Question count | 125 multiple-choice questions |
| Time allowed | 4 hours 15 minutes, plus a separate 10-minute break |
| Delivery | Kryterion/Webassessor at test centers; select ACG event exams are paper-and-pencil |
| Scoring model | Criterion-referenced total-score passing standard (not a fixed percentage) |
| 2025 reported pass rate | 58% (84 passes among 145 approved candidates) |
| Active credential holders | 1,216 as of January 1, 2026 |
| Largest domains | Conducting Commissioning Activities 24%, Existing Building Commissioning 23% |
For a deeper breakdown of how these numbers were reported and what they imply about difficulty, see CxA Pass Rate 2026: What the Data Shows and How Hard Is the CxA Exam? Complete Difficulty Guide 2026.
Registration, Fees, and Timing
ACG opened a July 8, 2026 application cycle that includes one exam attempt. Pricing depends entirely on your employment relationship with ACG, not on your experience level or exam history:
- $350 - employee of a Certified Member company
- $400 - employee of a company with a complete pending membership application
- $2,500 - all other applicants
- Candidates testing through a qualifying ACG event have their exam cost bundled into paid event registration; any optional workshop is billed separately
There is no mandatory prep course baked into the application fee, so whatever study resources you use are a separate line item. For a calendar view of application windows and what "July 8, 2026" actually locks in, check CxA Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Format, Delivery, and Scoring
The exam is closed book. You're allowed a scientific non-programmable calculator and nothing else - no adaptive delivery has been verified for this exam, so every candidate works through the same fixed pool of 125 questions in the allotted window. Scoring uses a criterion-referenced total-score passing standard, meaning the pass point is set against a defined body of knowledge rather than curved against other test-takers in your session.
Key Takeaway
Because scoring is criterion-referenced on total score, there's no partial credit for "knowing most domains." Weak performance in one heavily weighted domain can sink an otherwise strong attempt - plan your review time accordingly.
The current ACG handbook carries mixed February 17 and July 10, 2026 revision indicators, so always pull the latest version before you lock your study plan. ACG also updated its primary study reference on March 10, 2025, to the Building Systems Commissioning Guideline Part 1 - if your prep materials still cite an older reference document, replace them. For exactly how many questions you need right versus the scoring threshold, read CxA Passing Score 2026: Exactly What You Need to Pass.
The Seven Domains at a Glance
The CxA blueprint covers seven domains, and the weighting is not evenly distributed. Two domains alone account for 47% of the exam.
Domain 3: Conducting Commissioning Activities (24%)
The single largest domain. Expect scenario questions on functional performance testing, issue resolution, system integration verification, and coordinating trades during the construction and acceptance phases.
- Functional testing sequencing and documentation
- Deficiency tracking and resolution workflows
- Field verification against design intent
Domain 6: Conducting Existing Building Commissioning (23%)
Nearly as large as Domain 3. This covers retro-commissioning and re-commissioning of occupied buildings, where you're diagnosing operating systems rather than verifying new construction.
- Benchmarking existing performance against original/updated intent
- Energy and operational diagnostics in occupied facilities
- Prioritizing corrective measures with building ownership and operations staff
The remaining five domains split the balance: Preparing Commissioning Documentation (19%), Managing Commissioning Projects (18%), Conducting On-Going Commissioning (7%), Completing Warranty Phase Activities (5%), and Managing Training Activities (4%). Don't let the small percentages fool you into skipping them entirely - a candidate who ignores the four smallest domains is still giving up 16% of the exam collectively. A full content walkthrough of all seven areas is available in CxA Exam Domains 2026: Complete Guide to All 7 Content Areas.
Eligibility Tracks Cheat Sheet
You cannot sit for the CxA exam without first clearing an eligibility track. ACG defines four paths based on education and years of commissioning-related experience:
- PE or licensed architect + 3 years of commissioning experience
- Building-sciences bachelor's degree (or equivalent military training) + 5 years
- Two-year degree or non-building bachelor's degree (or equivalent military training) + 8 years in the building industry, including 5 years of commissioning
- High school diploma/GED + 10 years in the building industry, including 5 years of commissioning
Beyond the years-of-experience math, every applicant must document at least three qualifying commissioning projects and demonstrate six of eight specified commissioning activities, plus submit education/license evidence, employer and project verification, an independence attestation, and signed ethics agreements. There's no shortcut course that substitutes for this documentation. If you're unsure which track fits your background, walk through CxA Requirements 2026: Eligibility, Prerequisites & How to Qualify before you spend money on an application.
A Domain-Weighted Study Plan
Generic study advice rarely accounts for the fact that CxA's domain weights are lopsided. The plan below allocates time proportional to exam weight rather than splitting study evenly across all seven domains.
Domain 3 - Conducting Commissioning Activities
- Review functional performance testing protocols end to end
- Drill deficiency-tracking and resolution scenarios
Domain 6 - Existing Building Commissioning
- Study retro-commissioning diagnostic sequencing
- Compare new-construction versus occupied-building workflows
Domains 1 & 2 - Managing Projects & Documentation
- Review commissioning plan structures and project-phase responsibilities
- Practice documentation sequencing from design through acceptance
Domains 4, 5, 7 - Training, Warranty, Ongoing CX
- Cover training-activity oversight and warranty-phase checklists
- Review ongoing commissioning principles for occupied systems
Full-Length Review
- Take timed practice sets under the 4-hour-15-minute constraint
- Re-test weak domains identified in earlier weeks
This isn't a rigid template - it's a reflection of where exam weight actually sits. For a more detailed first-attempt strategy, see CxA Study Guide 2026: How to Pass on Your First Attempt, and build your timed-practice habit using realistic practice questions modeled on the actual exam format.
Recertification in Three Years
Earning the CxA isn't a one-time event. ACG requires recertification every three years, and the requirements are concrete:
- One qualifying commissioning project completed during the cycle
- 50 total points, including a mandatory minimum of 25 continuing education (CE) points
- Annual independence maintenance attestation
- Annual recertification fees: $200 for member or applicant-company employees, $2,500 for all others
Who Actually Hires a CxA
With 1,216 active holders as of January 1, 2026, the CxA credential remains a relatively small, specialized pool compared to broader construction and engineering certifications. That scarcity is part of why employers in mechanical, electrical, and building-systems commissioning firms specifically seek it out when staffing commissioning authority roles on new construction, retro-commissioning, and ongoing commissioning contracts.
Typical hiring contexts include commissioning agencies, mechanical/electrical engineering firms with a commissioning division, facility owners managing large portfolios, and general contractors who need an independent third-party verifier. Because the credential explicitly requires an independence attestation at both application and renewal, CxA holders are often engaged precisely because they are not the designer or installer of the systems they're verifying - that separation is the point.
If you're evaluating whether this credential fits your career trajectory, compare the data points in CxA Salary Guide 2026: Complete Earnings Analysis and Is the CxA Certification Worth It? Complete ROI Analysis 2026, and browse current openings referenced in CxA Jobs. For a plain-language refresher on what the letters actually mean before you commit to the eligibility paperwork, start with What Is CxA?.
Key Takeaway
The independence requirement isn't just paperwork - it's the market differentiator that makes employers specifically request CxA holders over in-house staff for verification work.
Frequently Asked Questions
125 multiple-choice questions, with 4 hours 15 minutes allotted plus a separate 10-minute break. The exam is closed book, and only a scientific non-programmable calculator is permitted.
It depends on your employer's ACG status: $350 for Certified Member-company employees, $400 for employees of a company with a pending membership application, and $2,500 for everyone else. Candidates testing at a qualifying ACG event have the exam bundled into event registration.
Conducting Commissioning Activities (24%) and Existing Building Commissioning (23%) together make up nearly half the exam content, so they deserve the largest share of study time, followed by Preparing Commissioning Documentation (19%) and Managing Commissioning Projects (18%).
The reported 2025 pass rate was 58%, based on 84 passes among 145 approved candidates. This figure is not explicitly broken out by first-time test-takers.
No. Recertification every three years requires one qualifying project and 50 total points (at least 25 from mandatory continuing education), plus annual independence attestation and fees - not a repeat exam.
Keep this page bookmarked as your quick-reference sheet, but pair it with full-length timed practice before exam day - review the complete domain guide and run through scenario-style questions on the main practice test platform so the format feels familiar when the 4-hour-15-minute clock actually starts.