- What the Credential Actually Is
- Who Issues It and How It Is Delivered
- The Six Exam Domains
- Exam Format and Question Style
- Eligibility Pathways and Candidate Status
- Registration, Fees and Testing Windows
- Who Hires CRES Holders
- Sequencing Your Preparation by Domain
- Keeping the Credential Active
- Frequently Asked Questions
- CRES means Certified Radiology Equipment Specialist, an AAMI/ACI credential for biomedical technicians who support radiology equipment.
- The exam has 165 multiple-choice questions, three hours, closed book, with a simple calculator permitted.
- Healthcare IT, technology and function, and problem solving each carry approximately 25% of the content.
- Full certification requires BMET experience; a degree alone never replaces the work-experience requirement.
What the Credential Actually Is
CRES stands for Certified Radiology Equipment Specialist. It is a professional certification for biomedical equipment technicians (BMETs) who install, maintain, troubleshoot and support the equipment used in diagnostic imaging and radiology departments. Think X-ray systems, fluoroscopy, CT, and the networked systems that move images from the modality to the people who read them.
It helps to be precise about what this credential is not. It is not a radiologic technologist credential, which certifies the clinicians who operate imaging equipment and position patients. It is also unrelated to any refrigeration or energy certification that happens to share a similar acronym. The CRES is a technical service credential: it validates that the person keeping the imaging fleet working understands the electronics, the software, the safety requirements and the diagnostic reasoning behind that work.
If you are still sorting out the terminology, our short explainers on what CRES stands for and what CRES is cover the naming question in more depth. This article focuses on how the certification works in practice.
Who Issues It and How It Is Delivered
The credential is issued by the Association for the Advancement of Medical Instrumentation (AAMI) and administered through its certification program, ACI. You will see AAMI refer to ACI as the AAMI Certification Institute on its certification overview and the AAMI Credentials Institute on its FAQ page. These are the same AAMI program under two names, not separate issuers, so do not be thrown if you see both while researching.
Testing is computer-based at approved Kryterion testing centers, and you schedule your seat through Webassessor. That is an in-person, test-center experience. If you have read about other certifications that offer remote proctoring from home, do not assume the same applies here. Plan for travel to an approved site and for the usual identification and check-in procedures that come with a proctored center exam.
The Six Exam Domains
The CRES content outline divides the exam into six areas. AAMI labels every percentage as approximate, and it lists three areas as co-largest at roughly 25% each, which together make up about three-quarters of the exam. Those allocations replace older weightings you may still see quoted on outdated study sites, so always check against the current outline. For a deeper walkthrough of each area, see our complete guide to all six CRES content areas.
| Domain | Approximate Weight |
|---|---|
| Domain 1: Anatomy & Physiology | 7% |
| Domain 2: Fundamentals of Electricity and Electronics | 10% |
| Domain 3: Healthcare Information Technology | 25% |
| Domain 4: Healthcare Technology and Function | 25% |
| Domain 5: Healthcare Technology Problem Solving | 25% |
| Domain 6: Public (employee, patient, visitor) Safety in the Healthcare Facility | 8% |
The three heavyweight domains
Domain 3: Healthcare Information Technology (approx. 25%)
Modern imaging equipment is a networked computing system. This domain tests whether you can work in that environment, not just at the console.
- Network fundamentals relevant to imaging devices and the systems they connect to
- How modalities communicate image and patient data with archives and viewing systems
- The interaction between clinical devices, hospital IT infrastructure and information security
- Recognizing when a "broken scanner" is actually a network, configuration or integration fault
Domain 4: Healthcare Technology and Function (approx. 25%)
This is the "how does it work" domain. Expect questions about the operating principles and subsystems of radiology equipment and the way the pieces cooperate to produce an image.
- Major subsystems of imaging equipment and what each contributes
- Normal operating behavior, so you can tell what correct looks like
- Preventive maintenance and performance verification concepts
- How operator-facing functions map to underlying hardware
Domain 5: Healthcare Technology Problem Solving (approx. 25%)
Here the exam rewards structured diagnostic thinking. Scenarios describe a symptom, and you must choose the most sensible next step or most probable cause.
- Isolating a fault to a subsystem using symptoms, error behavior and measurements
- Deciding between hardware, software, network and user-error explanations
- Sequencing troubleshooting steps efficiently rather than swapping parts at random
- Interpreting test results and verifying a repair actually restored function
The smaller domains still matter
Do not treat the remaining 25% or so of the exam as optional. Anatomy & Physiology (7%) exists because you cannot understand why imaging equipment behaves the way it does without knowing what it is imaging and what clinicians are looking for. Fundamentals of Electricity and Electronics (10%) is the foundation under every troubleshooting scenario: circuit behavior, measurement, and the components found in power and control systems. Public Safety in the Healthcare Facility (8%) covers protecting employees, patients and visitors, which in a radiology context naturally intersects with radiation, electrical and general facility safety. A candidate who ignores these areas gives away points that are surprisingly easy to earn.
Exam Format and Question Style
The CRES exam consists of 165 multiple-choice questions with a three-hour time limit. It is closed-book, so no reference materials, though a simple calculator is permitted. That works out to a little over a minute per question, which is comfortable for recall items and tight for the longer scenario questions in the problem-solving domain.
Because the content outline emphasizes technology function and troubleshooting, expect a mix of question types:
- Recall items that confirm you know terminology, components and safety requirements.
- Application items that give you a short situation and ask what a competent technician would do.
- Calculation items where the permitted simple calculator is relevant, typically basic electrical relationships rather than advanced mathematics.
Scoring is criterion-referenced. The passing standard is set through a process called the modified Angoff method, in which subject-matter experts judge how a minimally competent candidate would perform on each question. That means the cut score reflects a defined competence level rather than a guessed fixed percentage, and you should be wary of any site that states a precise "you need X%" figure without a source. We unpack this on the CRES passing score page, and the difficulty guide discusses what the format means for preparation.
Eligibility Pathways and Candidate Status
One of the defining features of the CRES is that it is an experience-based credential. You cannot simply study and sit for full certification straight out of a classroom. AAMI publishes three routes to full eligibility:
- Degree pathway: an associate degree or higher in electronics, technology or science, plus two years of full-time BMET experience.
- Military pathway: completion of a U.S. military biomedical equipment technology program, plus two years of full-time BMET experience.
- Experience-only pathway: four years of full-time BMET experience.
There is also a specialty-focus requirement. At least 40% of your work experience during the preceding two years, or 25% during the preceding five years, must be in the designated specialty, which here means radiology equipment. This is what separates the CRES from a general biomedical credential: your recent hands-on work must genuinely involve imaging.
Candidate status
If you have the qualifying degree, the military program, or two years of full-time BMET experience but have not yet met the full requirements, you may qualify as a candidate. Successful candidates have five years to satisfy the full-certification requirements. When you claim the degree or military route, you must provide documentation. A point worth underlining: a bachelor's degree does not replace the work-experience requirement. Education shortens the experience you need; it never eliminates it.
Our CRES requirements guide walks through how to document each pathway and common application stumbling blocks.
Registration, Fees and Testing Windows
Examination fees depend on AAMI membership:
| Item | Member | Nonmember |
|---|---|---|
| Initial examination | $410 | $460 |
| Retake | $355 | $405 |
Testing is offered in two regular windows each year: May 1-15 and November 1-15. Deadlines fall well before the window opens, so plan backward. For the November 1-15, 2026 window, the application deadline is October 16, and late registration closes October 23 with a $50 late fee. Because you also need approved eligibility documentation, do not leave your application to the final week; verification of experience can take longer than candidates expect.
Key Takeaway
Work backward from the test window. Gather employer verification and any degree or military documentation first, apply before the standard deadline to avoid the late fee, and then book your seat through Webassessor at a Kryterion site. See the exam dates and scheduling guide for the full timeline and the cost breakdown for budgeting beyond the exam fee.
Who Hires CRES Holders
The credential is relevant wherever imaging equipment has to be kept running and compliant. In practice that points to a few kinds of employers:
- Hospital clinical engineering and biomedical departments that maintain their own imaging fleet.
- Independent service organizations that contract to maintain radiology equipment for facilities without a large in-house team.
- Equipment manufacturers and their field-service organizations, which employ field engineers who install and repair imaging systems.
- Outpatient imaging centers and multi-site health systems that need technicians comfortable with both the equipment and its network environment.
Because Domain 3 weights healthcare IT so heavily, technicians who can bridge the gap between the modality and the hospital network are especially valuable. If you are weighing the career upside, our salary analysis and ROI discussion examine the economics without relying on invented numbers, and the CRES jobs overview describes typical roles.
Sequencing Your Preparation by Domain
Rather than a generic study calendar, build your plan around how the domains depend on each other. The electricity and electronics fundamentals support the technology-function material, which in turn supports troubleshooting. A sensible order looks like this:
Foundations first
- Electricity and Electronics (10%): circuit behavior, measurement, power concepts
- Anatomy & Physiology (7%): what imaging systems are designed to visualize
- Safety (8%): facility, electrical and radiation-related safety principles
The knowledge-heavy 25% blocks
- Healthcare Technology and Function: subsystems and normal operation of radiology equipment
- Healthcare Information Technology: networking, image data flow, device integration
Apply it
- Healthcare Technology Problem Solving: scenario-based fault isolation
- Timed mixed-domain question sets to practice pacing across 165 items
Troubleshooting comes last because it draws on everything else; you cannot isolate a network fault without Domain 3 knowledge or diagnose a subsystem failure without Domain 4. For resource suggestions and a fuller schedule, see the CRES study guide, the training overview, and the one-page cheat sheet for last-week review. To test yourself against realistic question styles, try the CRES practice tests.
Keeping the Credential Active
Certification is not a one-time event. To renew, you need at least 30 ACI CEUs in a three-year reporting cycle, and at least 15 of those must be in Category IV: Professional Development. You report your activity through My Active CEU Journal and pay a renewal fee of $100 for members or $150 for nonmembers. According to the current FAQ, the CEUs must be earned by December 31 of the recertification year.
One practical caution about timing: older reference material describes the first cycle as the remainder of your certification year plus three full calendar years. Because that detail could not be re-verified against the latest handbook, do not calculate your own deadline from an assumption. Use the actual expiration date that ACI assigns to you, and track your CEUs from the day you certify rather than the year before renewal.
Frequently Asked Questions
It certifies that a biomedical equipment technician has the knowledge and experience to support radiology equipment, assessed against six content domains covering anatomy, electronics, healthcare IT, technology function, problem solving and safety.
AAMI issues it, administered through its ACI certification program. AAMI uses both "AAMI Certification Institute" and "AAMI Credentials Institute" for ACI, but they describe the same program.
There are 165 multiple-choice questions with a three-hour limit. The exam is closed-book, and a simple calculator is permitted.
Full certification requires BMET experience under all three pathways. Candidate status is available if you hold the qualifying degree, military program or two years of experience, and you then have five years to complete the full requirements.
Our pages on CRES certification, what a CRES is, and the meaning of CRES cover the fundamentals from several angles.