- What the CER Exam Actually Tests
- All 7 Domains: Weights, Topics, and What HSPA Expects
- Domain 1: Microbiology and Infection Control (12%)
- Domain 2: Endoscope Purpose, Design and Structure (10%)
- Domain 3: Work Area Design (12%)
- Domain 4: Endoscope Processing Steps (32%)
- Domain 5: Endoscope Handling, Transport and Storage (16%)
- Domain 6: Endoscope Tracking, Repair and System Maintenance (10%)
- Domain 7: Human Factors That Impact Endoscope Systems (8%)
- How to Allocate Your Study Time Across All 7 Domains
- Exam Format, Registration, and What to Expect at Prometric
- Frequently Asked Questions
- The CER exam covers 7 domains across 125 scored questions (plus 25 unscored) with a 3-hour time limit.
- Domain 4 (Endoscope Processing Steps) is the largest at 32%-nearly one-third of your scored exam.
- Domains 1, 3, and 5 together account for another 40%, making them equally critical to study.
- The exam costs $140, requires 3 months of documented hands-on experience, and is administered via Prometric.
What the CER Exam Actually Tests
The Certified Endoscope Reprocessor (CER) credential is administered by the Healthcare Sterile Processing Association (HSPA) and is designed specifically for professionals who clean, disinfect, and reprocess flexible endoscopes. Unlike broader sterile processing certifications, the CER is laser-focused on one of the most infection-sensitive tasks in any healthcare environment.
The exam sits at 150 multiple-choice questions total. Of those, 125 are scored and 25 are unscored pretest questions embedded randomly throughout. You won't know which questions count-so treat every question as live. You have 3 hours to complete the exam, which works out to roughly 72 seconds per question on average. Most candidates who struggle don't run out of time; they run out of preparation on specific domains.
Passing is determined by a criterion-referenced Angoff/Beuk methodology. HSPA does not publish a public numeric cut score, so chasing a specific percentage is not a useful strategy. What matters is demonstrating competency across all 7 domains, not just the heavy-hitters.
All 7 Domains: Weights, Topics, and What HSPA Expects
Before drilling into each domain individually, here is how the 7 content areas stack up against one another. Understanding proportional weight helps you make smarter decisions about where to invest study hours.
| Domain | Name | Exam Weight | Approx. Scored Questions |
|---|---|---|---|
| 1 | Microbiology and Infection Control | 12% | ~15 |
| 2 | Endoscope Purpose, Design and Structure | 10% | ~13 |
| 3 | Work Area Design | 12% | ~15 |
| 4 | Endoscope Processing Steps | 32% | ~40 |
| 5 | Endoscope Handling, Transport and Storage | 16% | ~20 |
| 6 | Endoscope Tracking, Repair and System Maintenance | 10% | ~13 |
| 7 | Human Factors That Impact Endoscope Systems | 8% | ~10 |
Even Domain 7, the smallest at 8%, represents roughly 10 scored questions-enough to meaningfully shift your result. No domain is truly optional. For a deeper look at what difficulty looks like across all of these areas, see our guide on how hard the CER exam is and what makes it challenging.
Domain 1: Microbiology and Infection Control (12%)
Domain 1: Microbiology and Infection Control
This domain establishes the scientific foundation for everything else on the exam. Candidates must understand why endoscope reprocessing is so critical from an infection control standpoint.
- Classification of microorganisms: bacteria, viruses, fungi, prions, and spores
- Chain of infection and how endoscopes function as potential vehicles for transmission
- Spaulding Classification system and how it categorizes endoscopes as semicritical devices
- Standard and transmission-based precautions relevant to endoscope handling
- Biofilm formation, what accelerates it, and why it makes reprocessing harder
- Outbreak investigation basics and the role of the CER in infection prevention
Questions in Domain 1 tend to test conceptual understanding over rote memorization. Expect scenario-based questions like: "A patient is diagnosed with an endoscopy-associated infection. Which step in the reprocessing cycle is most likely to be the contributing factor?" That kind of applied reasoning is what distinguishes the CER from a simple knowledge quiz.
For in-depth coverage of every topic in this domain, visit the CER Domain 1: Microbiology and Infection Control complete study guide.
Domain 2: Endoscope Purpose, Design and Structure (10%)
Domain 2: Endoscope Purpose, Design and Structure
You cannot properly reprocess what you don't understand. Domain 2 ensures candidates can identify endoscope components, understand their clinical function, and recognize why certain design features create reprocessing challenges.
- Types of endoscopes: gastroscopes, colonoscopes, bronchoscopes, duodenoscopes, and more
- Internal channel architecture-working channels, air/water channels, suction channels
- Elevator mechanisms and recessed components unique to duodenoscopes (high-risk areas)
- Flexible vs. rigid endoscope distinctions
- How endoscope design directly influences the selection of reprocessing method
Duodenoscope-specific questions have become increasingly common in CER exams, reflecting real-world concern about difficult-to-clean elevator mechanisms. Candidates who only study generic endoscope anatomy often get tripped up here. The CER Domain 2: Endoscope Purpose, Design and Structure study guide goes deep on the component-level details that appear on the exam.
Domain 3: Work Area Design (12%)
Domain 3: Work Area Design
Physical environment is not just background context-it is a patient safety variable. Domain 3 tests whether candidates understand how a properly designed reprocessing area protects both patients and staff.
- Separation of soiled and clean areas; unidirectional workflow principles
- Ventilation requirements: air exchanges per hour, negative vs. positive pressure zones
- Sink design, sink sizing, and water quality requirements
- Personal protective equipment (PPE) requirements by zone
- Regulatory standards and guidelines from AAMI, SGNA, and AORN
- Equipment placement and ergonomic considerations
A common mistake candidates make is treating Domain 3 as "common sense." In reality, the exam tests specific regulatory requirements-not general cleanliness intuitions. Knowing that a reprocessing room requires a minimum number of air changes per hour, for example, is the kind of specific detail that separates passing candidates from those who fall just short. Read the CER Domain 3: Work Area Design complete study guide for a full breakdown.
Domain 4: Endoscope Processing Steps (32%)
This is the most heavily weighted domain on the CER exam by a wide margin. At 32%, it accounts for approximately 40 of your 125 scored questions. If you walk out of your exam session having mastered Domain 4 and struggled everywhere else, your odds are still poor. But if you struggle here, you almost certainly will not pass regardless of performance elsewhere.
Domain 4: Endoscope Processing Steps
Candidates must know the complete reprocessing sequence in order, as well as the rationale behind each step and what can go wrong if a step is skipped or performed incorrectly.
- Point-of-use pre-cleaning: timing, wiping, suctioning, and flushing immediately after patient use
- Leak testing: manual and automated methods, interpreting results, and what to do when a leak is detected
- Manual cleaning: enzymatic detergent selection, dilution ratios, soak times, brushing technique for each channel type
- Visual inspection post-cleaning and documentation requirements
- High-level disinfection (HLD): liquid chemical germicides (LCGs), automated endoscope reprocessors (AERs), contact time, temperature, and concentration verification
- Sterilization: when it is required vs. when HLD is sufficient, and available methods
- Rinsing protocols after HLD: sterile water vs. filtered water requirements
- Drying: alcohol flushing, forced air, and why inadequate drying enables biofilm
- MRC and reprocessing cycle documentation
Every subtopic within Domain 4 can appear in multiple question formats: definition questions, sequence-ordering questions ("which step comes next"), consequence questions ("what happens if the drying step is omitted"), and best-practice selection questions. The CER Domain 4: Endoscope Processing Steps complete study guide breaks each sub-step down with exam-style practice scenarios.
Domain 5: Endoscope Handling, Transport and Storage (16%)
Domain 5: Endoscope Handling, Transport and Storage
The second-largest domain tests what happens to an endoscope before and after the processing steps-equally important for preventing patient harm.
- Transport containers: requirements, labeling, and contamination prevention during soiled transport
- Hanging vs. cabinet storage: HSPA and SGNA guidelines on each method
- Maximum hang time and storage duration before re-reprocessing is required
- Environmental controls in storage areas: humidity, temperature, and air quality
- Handling techniques that prevent damage during transport and storage
- Scope of practice boundaries: when a technician should escalate vs. proceed
Storage duration questions trip up many candidates. Guidelines have evolved, and the exam reflects current HSPA-recognized standards-not older "hang time" rules that some facilities still use. The CER Domain 5: Endoscope Handling, Transport and Storage study guide addresses the nuances in detail.
Domain 6: Endoscope Tracking, Repair and System Maintenance (10%)
Domain 6: Endoscope Tracking, Repair and System Maintenance
Tracking and documentation are not administrative extras-they are patient safety systems. Domain 6 tests operational and technical competency beyond hands-on reprocessing.
- Endoscope tracking systems: manual logs vs. electronic tracking, required data elements
- Patient traceability: linking scope serial number to specific patient encounters
- AER maintenance schedules and documentation requirements
- Recognizing signs of endoscope damage and appropriate escalation pathways
- Loaner endoscope protocols and reprocessing requirements before first use
- Quality indicators and performance metrics for reprocessing programs
Explore every testable topic in this content area through the CER Domain 6: Endoscope Tracking, Repair and System Maintenance complete study guide.
Domain 7: Human Factors That Impact Endoscope Systems (8%)
Domain 7: Human Factors That Impact Endoscope Systems
The smallest domain by weight, but uniquely important: it tests whether candidates understand the organizational, behavioral, and ergonomic factors that lead to reprocessing failures even when protocols are technically correct.
- Fatigue, distraction, and workload as contributors to processing errors
- The role of culture of safety in reprocessing departments
- Communication breakdowns between clinical and reprocessing staff
- Ergonomics: positioning, repetitive motion risks, and workspace layout effects on accuracy
- Training competency verification: initial and ongoing
- Policy adherence monitoring and accountability structures
Domain 7 questions often appear in scenario format: "A reprocessing technician working a double shift skips the manual flush step. What systemic factor most likely contributed to this error?" These are nuanced questions that reward candidates who understand healthcare systems thinking, not just procedural steps. See the CER Domain 7: Human Factors complete study guide for full coverage.
How to Allocate Your Study Time Across All 7 Domains
Given the domain weights, a proportional study schedule is more strategic than working through the content outline linearly. Here is a practical framework for candidates with 6-8 weeks before their exam date.
Foundation: Domains 1 and 2
- Master Spaulding Classification and biofilm science (Domain 1)
- Learn all endoscope types and internal channel anatomy (Domain 2)
- These domains build the conceptual scaffolding for everything in Domain 4
Infrastructure: Domains 3 and 6
- Work area design requirements, ventilation specs, and PPE zones (Domain 3)
- Tracking systems, documentation, and AER maintenance (Domain 6)
Core Focus: Domain 4 (Endoscope Processing Steps)
- Work through every reprocessing step in sequence-pre-cleaning through drying
- Practice scenario-based questions daily using a CER practice test tool
- Spend extra time on HLD chemical selection and AER operational requirements
Domain 5: Handling, Transport and Storage
- Master storage duration guidelines and hanging vs. cabinet storage rules
- Review transport container requirements and labeling standards
Domain 7 and Full Exam Simulation
- Human factors content: review safety culture, fatigue, and competency verification
- Complete full 150-question timed practice exams to simulate real Prometric conditions
- Identify weak domains and return to targeted review
For a detailed week-by-week plan with specific resource recommendations, see our CER Study Guide 2026: How to Pass on Your First Attempt. For question-format expectations by domain, the best CER practice questions guide explains what each domain actually looks like in multiple-choice format.
Exam Format, Registration, and What to Expect at Prometric
Registration and Prerequisites
The CER exam is administered by HSPA through Prometric Testing Centers nationwide. To be eligible, candidates must document a minimum of 3 months of hands-on endoscope reprocessing experience. Notably, the CRCST certification is not a prerequisite-candidates can pursue the CER independently of other HSPA credentials.
The exam fee is $140 USD. For a complete accounting of all associated costs including preparation materials and renewal fees, the CER Certification Cost 2026 breakdown covers every expense category.
At the Testing Center
The CER is a closed-book, computer-based exam. When you arrive at Prometric, you will complete a brief tutorial before the exam begins-take this seriously, as it demonstrates the navigation tools, flagging features, and review functions available during the exam. These tools matter for a 150-question, 3-hour sitting.
Certification Renewal
The CER credential renews annually. Maintenance requires completing 6 CE credits in endoscope reprocessing plus payment of the HSPA renewal fee. The annual renewal model means your knowledge must stay current-guidelines from SGNA, AAMI, and AORN continue to evolve. For the full renewal process, see the CER Recertification 2026 guide.
Once certified, the CER opens doors in ambulatory surgery centers, hospital GI labs, pulmonology departments, and endoscope repair and remanufacturing organizations. The credential signals employer-verifiable competency in a specialty area where reprocessing failures carry significant regulatory and liability consequences. For career trajectory information, see our CER Career Paths: Jobs, Industries and Growth Opportunities 2026.
Key Takeaway
Start your CER preparation with Domains 1 and 2 to build conceptual fluency, then invest the bulk of your study time-at least two full weeks-on Domain 4. Use timed practice exams under Prometric-like conditions to calibrate your pacing before exam day. Visit CER Exam Prep to access domain-specific practice questions organized by content area.
Frequently Asked Questions
The CER exam contains 150 multiple-choice questions total: 125 scored and 25 unscored pretest questions embedded randomly. Candidates have 3 hours to complete the exam at a Prometric Testing Center. You cannot distinguish scored from unscored questions, so answer every question with full effort.
Start with Domain 1 (Microbiology and Infection Control) and Domain 2 (Endoscope Purpose, Design and Structure) because they provide the conceptual foundation for Domain 4. Then prioritize Domain 4 (Endoscope Processing Steps) at 32%-it is the largest domain and the one most likely to determine your pass or fail outcome.
No. The CRCST is not a prerequisite for the CER. The only eligibility requirement is documenting at least 3 months of hands-on endoscope reprocessing experience. The CER can be pursued as a standalone credential or in addition to other HSPA certifications.
The CER exam fee is $140 USD. The certification renews annually and requires 6 CE credits specifically in endoscope reprocessing plus the HSPA renewal fee. Annual renewal keeps your credential active and your knowledge aligned with evolving guidelines from AAMI, SGNA, and AORN.
The CER exam through 2026 is built from the May 2022 content outline published by HSPA. This outline defines all 7 domains, their percentage weights, and the subtopics within each domain. Always verify that any third-party study materials reference this version before purchasing.
Ready to Start Practicing?
Now that you know exactly what each of the 7 CER domains covers and how they are weighted, put that knowledge to work. Our practice questions are organized by domain so you can target your weakest areas first-starting with the 32% that matters most.
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