- What Is CxA, Exactly?
- Who Grants the Certified Commissioning Authority Credential?
- Exam Format: Questions, Timing, and Delivery
- The Seven CxA Exam Domains
- Who Qualifies to Sit for the CxA Exam?
- Fees, Applications, and Testing Windows
- Maintaining CxA Certification
- Who Hires CxA-Certified Professionals?
- Planning Your CxA Study Timeline
- Frequently Asked Questions
- CxA (Certified Commissioning Authority) is awarded by the AABC Commissioning Group through its ACG Certification Council.
- The exam has 125 multiple-choice questions in 4 hours 15 minutes, plus a separate 10-minute break.
- Conducting Commissioning Activities (24%) and Existing Building Commissioning (23%) are the two heaviest domains.
- Application fees range from $350 for Certified Member-company employees up to $2,500 for all others, under the July 8, 2026 application cycle.
What Is CxA, Exactly?
CxA stands for Certified Commissioning Authority, a credential administered by the AABC Commissioning Group (ACG) through its ACG Certification Council. It is designed for building professionals who lead the commissioning process - the structured verification that HVAC, controls, and other building systems are designed, installed, and operated to meet the owner's project requirements. If you've landed here searching "what is CxA," this page is the baseline reference; for a deeper dive into the terminology itself, see our companion pieces on CxA Meaning and What Does CxA Stand For?
Unlike generic quality-assurance roles, a Certified Commissioning Authority is expected to manage the full lifecycle of a commissioning project - from documentation and functional testing through training oversight, warranty-phase follow-up, and ongoing performance verification in buildings that are already occupied. That breadth is exactly why the exam blueprint spans seven distinct domains rather than a narrow technical checklist.
Who Grants the Certified Commissioning Authority Credential?
The AABC Commissioning Group, through its ACG Certification Council, owns and administers the CxA credential. ACG sets the eligibility tracks, maintains the exam content outline, and publishes the handbook that governs application, testing, and recertification. If you want the full certification overview beyond this introductory piece, read CxA Certification, and if you're specifically trying to pin down the individual-practitioner meaning of the term, check What Is A CxA?
Testing is delivered through Kryterion/Webassessor at test centers. Some ACG-affiliated event exams are administered paper-and-pencil instead, and at-home proctoring has not been verified as an available option. There is no confirmed adaptive-delivery format - candidates should expect a fixed, linear exam rather than a computer-adaptive test.
Exam Format: Questions, Timing, and Delivery
The CxA exam consists of 125 multiple-choice questions administered over 4 hours and 15 minutes, with a separate 10-minute break built into the appointment (not counted against your working time). The exam is closed-book, though a scientific non-programmable calculator is permitted at the testing station.
Passing is determined by a criterion-referenced total-score standard - meaning your overall score across all 125 questions is measured against a fixed passing threshold rather than a curve relative to other test-takers. For the full mechanics of how that threshold is set and what it means for your preparation, see CxA Passing Score 2026: Exactly What You Need to Pass.
Key Takeaway
Because scoring is criterion-referenced and total-score based, you cannot "bank" a weak domain against a strong one in isolation - but you also aren't competing against a moving curve. Consistent performance across all seven domains matters more than acing one and guessing on another.
The Seven CxA Exam Domains
ACG's exam content outline splits the 125 questions across seven weighted domains. Understanding these weights is the single most important step in building an efficient study plan - a topic covered in full detail in CxA Exam Domains 2026: Complete Guide to All 7 Content Areas.
Domain 3: Conducting Commissioning Activities (24%)
The largest single domain. Candidates must know how to execute functional performance testing, coordinate trade contractors during startup and testing, and verify systems against the basis of design.
- Functional test development and execution sequencing
- Issue tracking and resolution during active commissioning
Domain 6: Conducting Existing Building Commissioning (23%)
Nearly as heavily weighted as Domain 3, this domain tests retro-commissioning and recommissioning knowledge for buildings already in operation.
- Diagnosing performance drift in existing systems
- Prioritizing corrective actions in occupied facilities
Domain 2: Preparing Commissioning Documentation (19%)
The second-largest domain, covering the written deliverables that drive a commissioning project.
- Owner's Project Requirements and Basis of Design documentation
- Commissioning plans and issue logs
Domain 1: Managing Commissioning Projects (18%)
Covers the project-management backbone: scheduling, stakeholder coordination, and scope management across the design and construction phases.
- Integrating commissioning milestones into the construction schedule
- Managing communication among owner, design, and contractor teams
The remaining three domains carry smaller but still testable weights: Conducting On-Going Commissioning (7%), Completing Warranty Phase Activities (5%), and Managing Training Activities (4%). Together these three cover post-occupancy performance monitoring, warranty-period issue resolution, and oversight of operator training - don't skip them just because they're lighter, since a weak showing across three smaller domains can still cost meaningful points on a total-score exam.
Who Qualifies to Sit for the CxA Exam?
ACG uses four separate eligibility tracks based on education, licensure, and years of building-industry and commissioning experience. A full breakdown lives in CxA Requirements 2026: Eligibility, Prerequisites & How to Qualify, but in summary:
- PE or architect license plus three years of commissioning experience
- Building-sciences bachelor's degree (or equivalent military training) plus five years of commissioning experience
- Two-year degree or non-building bachelor's (or equivalent military training) plus eight building-industry years, including five years of commissioning
- High school diploma or GED plus ten building-industry years, including five years of commissioning
Regardless of track, candidates must document at least three qualifying projects and demonstrate experience in six of eight specified commissioning activities. The application also requires education/license evidence, employer and project verification, and signed independence and ethics agreements. There is no mandatory prep course required before applying - but that doesn't mean the exam is easy to approach unprepared, as explored in How Hard Is the CxA Exam? Complete Difficulty Guide 2026.
Fees, Applications, and Testing Windows
As of the July 8, 2026 application cycle, the CxA application includes one exam attempt at the following rates:
| Candidate Type | Application Fee |
|---|---|
| Certified Member-company employee | $350 |
| Employee of a company with a pending membership application | $400 |
| All other candidates | $2,500 |
Candidates attending a qualifying ACG event have testing bundled into their paid event registration; any optional workshop is billed separately. For a complete cost breakdown including recertification fees, see CxA Certification Cost 2026: Complete Pricing Breakdown. Testing windows and application deadlines shift from cycle to cycle, so check current scheduling details in CxA Exam Dates 2026: Testing Windows, Deadlines & Scheduling before you commit to a study timeline.
ACG's current linked 2026 handbook shows mixed revision indicators (February 17 and July 10), so always verify you're reading the latest version before finalizing your application paperwork.
Maintaining CxA Certification
CxA certification is not permanent. Holders must recertify every three years by completing one qualifying project and accumulating 50 points, of which 25 must come from mandatory continuing education. Certified individuals must also maintain independence annually and pay ongoing fees - $200 per year for member or applicant-company employees, or $2,500 for all others. These recurring obligations are a meaningful factor when weighing the credential's long-term value, a question tackled directly in Is the CxA Certification Worth It? Complete ROI Analysis 2026.
Key Takeaway
Budget for recertification the same way you budget for the initial exam - the three-year cycle and annual independence/fee requirements are ongoing costs of holding the credential, not one-time expenses.
Who Hires CxA-Certified Professionals?
Employers seeking Certified Commissioning Authority holders are typically commissioning agencies, mechanical/electrical engineering firms, owner's representative organizations, and facility-operations teams responsible for large commercial, institutional, or healthcare buildings. Because the exam blueprint devotes nearly half its weight to Conducting Commissioning Activities and Existing Building Commissioning combined, employers value CxA holders specifically for hands-on functional testing leadership and retro-commissioning expertise on buildings already in service - not just new-construction oversight.
If you're exploring career paths and compensation ranges tied to this specific credential, see CxA Salary Guide 2026: Complete Earnings Analysis and browse current openings in CxA Jobs. Many candidates also pursue structured coursework before sitting for the exam - explore options in CxA Training, even though ACG does not mandate a specific prep course for eligibility.
Planning Your CxA Study Timeline
Given the domain weighting, your study schedule should mirror the exam blueprint rather than treating all seven domains equally. Allocate the most calendar time to Domain 3 (Conducting Commissioning Activities, 24%) and Domain 6 (Existing Building Commissioning, 23%), since together they represent nearly half of all scored questions.
Documentation & Project Management Foundations
- Review Domain 1 (Managing Commissioning Projects) and Domain 2 (Preparing Commissioning Documentation)
- Build familiarity with Owner's Project Requirements and Basis of Design terminology
Core Commissioning Execution
- Deep-dive Domain 3 (Conducting Commissioning Activities) - the single heaviest domain
- Practice functional test sequencing and issue-resolution scenarios
Existing Buildings & Smaller Domains
- Focus on Domain 6 (Existing Building Commissioning)
- Cover Domains 4, 5, and 7 - Training, Warranty, and On-Going Commissioning
Full Review & Timed Practice
- Run full-length timed sessions matching the 4-hour 15-minute format
- Revisit weak domains identified through practice scoring
For a structured, step-by-step prep plan built around these same domain weights, read CxA Study Guide 2026: How to Pass on Your First Attempt. And if you want a fast-reference summary of must-know facts to review in the final days before your appointment, bookmark CxA Cheat Sheet 2026: One-Page Review of Must-Know Facts.
Running realistic, timed practice questions on our practice test platform before exam day helps you gauge pacing across all 125 questions and identify which of the seven domains still needs reinforcement. Because the passing standard is criterion-referenced across the full exam, broad-based practice on the full-length practice tests tends to be more useful than cramming a single domain.
Frequently Asked Questions
In this article and across cxaexam.com, CxA stands for Certified Commissioning Authority, the credential administered by the AABC Commissioning Group's ACG Certification Council. See What Does CxA Mean? for more on the terminology.
The exam contains 125 multiple-choice questions, administered over 4 hours and 15 minutes with a separate 10-minute break.
Conducting Commissioning Activities carries the highest weight at 24%, closely followed by Conducting Existing Building Commissioning at 23%.
No mandatory prep course is required for eligibility. Candidates qualify through one of four education/experience tracks, documented qualifying projects, and verification of specified commissioning activities.
Recertification occurs every three years and requires one qualifying project plus 50 points, including 25 mandatory continuing education points, along with ongoing independence and fee maintenance.