- What This CRST Credential Actually Is
- Two Routes to Eligibility
- Documenting Four Years of Experience
- Application, Payment and Eligibility Window
- Fees and the $5 Nonmember Discrepancy
- Exam Format You Must Be Ready For
- Test-Day Requirements
- Does Your Experience Match the 16 Domains?
- Sequencing Your Preparation Around the Eligibility Clock
- After You Qualify: Retests and Renewal
- Frequently Asked Questions
- Qualify with an active CARO or CIRO credential, or four years of progressively responsible refrigeration experience.
- The experience route requires a separate Verification of Experience form before RETA can process your application.
- Application eligibility lasts one year from payment; request any 90-day extension before that year expires.
- The exam is 150 computer-based questions in three hours, with 70% required to pass.
What This CRST Credential Actually Is
On this site, CRST means Certified Refrigeration Service Technician, the industrial refrigeration credential issued by the Refrigerating Engineers & Technicians Association (RETA). It is not the Canadian safety-technician credential that happens to share the abbreviation, and nothing in this article applies to that program. If you are still orienting yourself, our explainers on what CRST certification is and what CRST stands for cover the basics before you dive into eligibility.
The requirements below come from the 2026 CRST Exam Information Handbook (Revision 09, approved January 2, 2026, valid January 1 through December 31, 2026). Because RETA revises the handbook annually, treat this page as a working guide and confirm anything date-sensitive against the current handbook before you pay.
Two Routes to Eligibility
RETA gives candidates two ways in. Both also require compliance with the RETA Code of Conduct, so a clean professional record matters regardless of which route you take.
| Route | What You Need | Extra Paperwork |
|---|---|---|
| Credential route | An active CARO or CIRO credential | None beyond the standard application |
| Experience route | At least four years of progressively responsible refrigeration experience | Separate Verification of Experience form, required before the application can be processed |
Which route fits you?
If you already hold an active CARO or CIRO, the credential route is the cleaner path: your existing certification is the proof, and there is no experience form to chase down. Candidates without one of those credentials rely on the experience route, which puts the burden of documentation on you and your supervisors. The word "active" matters. A lapsed CARO or CIRO does not satisfy the credential route, so check your standing before you assume you qualify.
Documenting Four Years of Experience
"Progressively responsible refrigeration experience" is the phrase RETA uses, and it is worth reading closely. Four years of simply being employed near refrigeration equipment is a weaker case than four years in which your duties grew: from assisting on service calls, to independently troubleshooting, to taking ownership of systems, compliance tasks or other technicians' work. When your supervisor completes the Verification of Experience form, the narrative should show that growth.
Build your evidence before you apply
- List each employer, your dates of employment, and your title at each stage.
- Describe duties in the language of the exam's content areas: compressor service, oil analysis, condenser and cooling tower maintenance, controls, leak detection, and ammonia compliance work.
- Identify a supervisor or manager who can speak credibly to your hands-on responsibilities and is willing to complete the form promptly.
- Note any ammonia refrigeration compliance duties, such as documentation, inspections or safety program participation, since those map directly to the exam.
Do not start the clock on your preparation until the verification form is in motion. Because the application cannot be processed without it, a slow supervisor can stall your entire timeline.
Application, Payment and Eligibility Window
Once your application is approved and paid, your eligibility to test lasts one year from the date of payment. That single year is your working window for scheduling and sitting the exam. If life intervenes, a 90-day extension is available, but it must be requested before your eligibility period expires. Request it after the deadline and you should expect to start over rather than receive relief. For scheduling logistics, see our guide to CRST exam dates and scheduling.
Testing is delivered through the Kryterion Testing Network or RETA Network Testing Centers, and appointments are arranged through RETA staff rather than booked independently by the candidate. Build that coordination time into your plan, especially if you live far from a testing location.
Fees and the $5 Nonmember Discrepancy
The handbook lists initial fees of $770 for RETA members and $1,065 for nonmembers. A first discounted retest after a failure within one year costs $515 for members and $710 for nonmembers, and it requires a new application and payment. Our CRST certification cost breakdown goes deeper on total outlay.
| Fee Item | Member | Nonmember |
|---|---|---|
| Initial application and exam (handbook) | $770 | $1,065 |
| First discounted retest (within one year of failing) | $515 | $710 |
| Additional practice attempt | $59 each | |
The member versus nonmember gap is large enough to factor into your decision. Compare the savings against membership dues before you commit; that is a business decision only you can make, but the numbers are worth running. If you are weighing the whole investment, our ROI analysis of the CRST and salary guide can help.
Exam Format You Must Be Ready For
Eligibility is only the gate; the exam is the test. Know exactly what you are qualifying for:
- Delivery: computer-based, in English.
- Length: 150 multiple-choice questions in a three-hour limit.
- Scoring: 70% required to pass. Ten items are unscored pilot questions, leaving 140 scored items. You will not know which ones are pilots.
- Navigation: questions may be flagged and revisited.
For a closer look at the cut score, read our page on the CRST passing score, and for realistic expectations see how hard the CRST exam is.
How the 150 questions are distributed
RETA publishes question allocations by content area, not percentage weights. In domain order, the counts are 24, 16, 7, 11, 10, 6, 7, 7, 4, 13, 8, 7, 8, 7, 10 and 5, totaling 150. The table does not separate the pilot items by content area, so do not treat these as scored-only counts or convert them into official percentages.
Where the question volume sits
Two areas dominate the allocation and deserve proportionally more attention:
- Safety (24 questions): the largest single area.
- Compressors (16 questions): the second largest.
- Electric Service Motors, etc. (13 questions) and Condensers & Cooling Towers (11 questions) follow, with Vessels, Piping, Valves & Controls and CO2 Systems not far behind at 10 and 5 respectively in the published table.
Our complete guide to the 16 CRST content areas walks through each one in detail.
Test-Day Requirements
Meeting the eligibility rules is not enough if you are turned away at the testing center. The handbook specifies what to bring and what to leave behind.
- Identification: two forms of ID.
- Calculator: a simple, nonprinting, nonprogrammable calculator with its memory cleared.
- References: RETA supplies the permitted onscreen references. Personal books, notes and study-guide copies are not permitted.
Key Takeaway
Because references are supplied onscreen and personal materials are barred, practice navigating reference material under time pressure. Three hours for 150 questions leaves roughly 72 seconds per item, so you cannot afford to hunt blindly for every answer. Know where things live and recognize which questions you should answer from knowledge alone.
Does Your Experience Match the 16 Domains?
Qualifying on paper is different from being ready. Many candidates meet the four-year threshold while having deep experience in some areas and almost none in others. The exam covers 16 content areas, and your day-to-day job probably touches only some of them. Audit yourself honestly:
Areas that often surprise operators and service techs
- Oil Analysis: interpreting results and understanding what they say about system condition, not just changing oil.
- Purges: non-condensable removal is a specialty topic that some facilities handle rarely.
- Shaft & Bearing Maintenance: mechanical detail that candidates who focus on controls may have skipped.
- Ammonia Refrigeration Compliance: regulatory and documentation knowledge that field techs sometimes leave to a safety manager.
- CO2 Systems: a smaller allocation, but unfamiliar to technicians who have worked only on ammonia plants.
Technicians who hold a CARO or CIRO often come in strong on operations but may need extra work on service and troubleshooting topics such as Trouble Systems Operations and Leak Monitoring & Detection. Those with a maintenance-heavy background may find Ammonia Refrigeration Compliance and Safety the bigger lift. Employers in cold storage, food processing, distribution and industrial plants value this credential for exactly this blend of hands-on and compliance skill; our CRST jobs overview describes who tends to hire.
Sequencing Your Preparation Around the Eligibility Clock
Your one-year window starts at payment, so pay when you are prepared to study, not months before. A simple CRST-specific sequence keeps the large-allocation domains from being rushed. For a fuller plan, see our CRST study guide.
Largest allocations first
- Safety (24 questions) and Compressors (16 questions), since together they account for over a quarter of the exam.
- Ammonia Refrigeration Compliance alongside Safety, because the topics reinforce each other.
Mechanical and electrical systems
- Condensers & Cooling Towers, Vessels, Piping, Valves & Controls, Evaporators & Heat Exchangers, Pumps & Transfer Systems.
- Electric Service Motors, etc., Controls Maintenance, and Shaft & Bearing Maintenance.
Specialty topics and practice
- Oil Analysis, Purges, Insulation, Leak Monitoring & Detection, Trouble Systems Operations, CO2 Systems.
- Use your included official practice attempt, then review every miss by domain.
If you are curious how candidates fare, we discuss what is and is not known in our CRST pass rate article. We do not cite a pass-rate figure here because none is established in the verified handbook facts.
After You Qualify: Retests and Renewal
If you do not pass
A first discounted retest within one year of failing costs $515 for members and $710 for nonmembers. It requires a new application and payment, the minimum interval is two weeks, and the retest must be completed within 90 days after approval and payment. Plan your recovery study around the domains where you lost the most ground rather than rereading everything.
Staying certified
The certification lasts three years. The retrieved handbook requires holders whose credential has expired to retest rather than submit late professional development hours, so renewing on time is far cheaper than starting over. Previously reviewed RETA renewal information describes 24 relevant Professional Development Hours (2.4 CEUs), documented in the RETA Certification Database, plus an online renewal application and payment before expiration, with HAZWOPER training excluded from qualifying PDH. An earlier supplied record lists renewal pricing of $235 for members and $835 for nonmembers. These renewal details come from prior review of pages we could not re-retrieve, so reconfirm them with RETA before you quote a price or assume a particular course counts.
Frequently Asked Questions
No. An active CARO or CIRO is one route, but you can instead document at least four years of progressively responsible refrigeration experience. Either way, you must comply with the RETA Code of Conduct.
A separate Verification of Experience form. RETA cannot process your application until it is submitted, so arrange it with a supervisor early.
Eligibility lasts one year from payment. You can request a 90-day extension, but the request must be made before the one-year period expires.
The 2026 handbook lists $770 for members and $1,065 for nonmembers. RETA's program and application pages have shown $1,060 for nonmembers, a $5 conflict we cannot resolve here, so confirm your invoiced amount with RETA before paying.
No. Personal books, notes and study-guide copies are not permitted, and the calculator must be simple, nonprinting and nonprogrammable with its memory cleared. RETA supplies the permitted onscreen references, and you need two forms of ID.