- How the CSFA Exam Blueprint Is Structured
- Domain 1: Perioperative Care (55%)
- Domain 2: Ancillary Duties (14%)
- Domain 3: Basic Science (31%)
- Question Format and What "Scored" Actually Means
- Registration, Fees, and Test-Day Rules
- Turning Domain Weighting Into a Study Schedule
- Who Hires Based on These Domains
- Frequently Asked Questions
- Perioperative Care makes up 55% of the CSFA exam and drives most of your prep time.
- Ancillary Duties is only 14%, but skipping it risks losing easy points on a short domain.
- Basic Science accounts for 31%, covering anatomy, physiology, microbiology, and pharmacology.
- The exam has 175 questions (150 scored, 25 unscored pretest) with a 4-hour limit.
How the CSFA Exam Blueprint Is Structured
The NBSTSA doesn't test CSFA candidates randomly. Every version of the exam pulls from the same three content domains, weighted according to the official candidate handbook, so the proportion of questions in each area stays consistent no matter when you sit for it. Understanding this blueprint is the difference between studying broadly and studying strategically - and it's the foundation of every effective CSFA study plan built for first-attempt passing.
The three domains are:
- Domain 1: Perioperative Care - 55% of the exam
- Domain 2: Ancillary Duties - 14% of the exam
- Domain 3: Basic Science - 31% of the exam
That distribution isn't arbitrary. It reflects the actual proportion of time a working surgical first assistant spends in each functional area - the vast majority of your working life (and your exam) revolves around what happens in the OR itself, not the administrative or scientific periphery around it.
Domain 1: Perioperative Care (55%)
Perioperative Care is the largest and most consequential domain on the CSFA exam, and it's built around the real-time decision-making a first assistant performs before, during, and after a case. This domain is subdivided into pre-operative, intraoperative, and post-operative responsibilities - but intraoperative content is where the bulk of the weight sits.
Perioperative Care - What You Must Master
Candidates are tested on their ability to actively participate in surgical procedures as a first assistant, not just observe or assist passively.
- Tissue handling, retraction technique, and exposure principles across surgical specialties
- Hemostasis methods, including electrosurgery, ligation, and topical agents
- Wound closure techniques, suturing patterns, and stapling devices
- Positioning, prepping, and draping specific to procedure type
- Intraoperative complications and appropriate first-assistant response
- Post-operative wound assessment and dressing application
Because Intraoperative Procedures drives so much of Domain 1's weight, it deserves the largest single block of your study calendar. Questions here are frequently scenario-based: you're given a surgical situation and asked what the first assistant should do next, not simply asked to define a term. For a full breakdown of every subtopic, high-yield content, and sample question logic, see the dedicated CSFA Domain 1: Perioperative Care study guide.
Domain 2: Ancillary Duties (14%)
Ancillary Duties is the smallest domain by weight, but it's not a throwaway section. At 14%, it still represents roughly 21 scored questions - enough to swing a borderline score in either direction.
Ancillary Duties - What You Must Master
This domain covers the supporting responsibilities that surround direct surgical assisting: documentation, equipment, and professional practice standards.
- Instrument and equipment care, sterilization principles, and troubleshooting
- Documentation and charting responsibilities specific to the first assistant role
- Legal, ethical, and professional standards governing practice
- Communication and coordination with the surgical team and other departments
Because this domain is compact, it's also efficient to study - a focused review session can cover a large share of the tested content quickly. Candidates often underrate it simply because it's smaller, then lose easy points on test day. The full topic list and practice scenarios are covered in CSFA Domain 2: Ancillary Duties study guide.
Key Takeaway
Don't let a 14% weighting fool you into skipping Ancillary Duties entirely - it's small enough to master in a short, dedicated review block, so there's no excuse for leaving points on the table here.
Domain 3: Basic Science (31%)
Basic Science is the second-largest domain and the theoretical backbone that supports everything tested in Domain 1. This is where the exam checks whether you understand the "why" behind the surgical technique, not just the technique itself.
Basic Science - What You Must Master
Expect deep coverage of the scientific foundations a first assistant needs to anticipate complications and make sound intraoperative judgments.
- Anatomy and physiology by body system, with an emphasis on surgical relevance
- Microbiology and infection control principles applied to the sterile field
- Pharmacology relevant to anesthesia, hemostasis, and wound management
- Pathophysiology of common surgical conditions and disease processes
Basic Science questions can feel more like a nursing or physiology exam than a hands-on skills test, which surprises some candidates coming straight from a CAAHEP-accredited program. Because this domain accounts for nearly a third of your score, weak anatomy or pharmacology knowledge can quietly erode your overall performance even if your Perioperative Care knowledge is strong. The complete content breakdown is available in the CSFA Domain 3: Basic Science study guide.
Question Format and What "Scored" Actually Means
The CSFA exam consists of 175 total multiple-choice questions delivered by computer at a PSI testing center, but only 150 of those are scored. The remaining 25 are unscored pretest items the NBSTSA uses to evaluate future exam questions - and you won't know which is which while you're testing.
- Total questions: 175
- Scored questions: 150
- Unscored pretest questions: 25
- Time limit: 4 hours
- Passing score: 99 correct out of 150 scored questions
- Format: computer-based multiple choice
Because you can't identify which questions are unscored, the only reasonable strategy is to treat every question with equal seriousness. Guessing your way through items you assume are "just pretest" is a common and costly mistake. For a deeper look at difficulty patterns and how candidates typically experience the pacing, read How Hard Is the CSFA Exam? Complete Difficulty Guide.
| Metric | Detail |
|---|---|
| Total questions | 175 |
| Scored questions | 150 |
| Unscored pretest questions | 25 |
| Time allowed | 4 hours |
| Passing threshold | 99 correct scored answers |
| 2025 national first-take pass rate | 62% |
Registration, Fees, and Test-Day Rules
Before you can sit for the CSFA exam, you must be a graduate of a CAAHEP-accredited Surgical First Assistant program. Once eligible, registration and testing run through PSI, with fees varying based on AST membership status.
- Exam fee: $240 for AST members, $350 for all others
- Renewal by continuing education: $45 fee
- Renewal by examination: $450 for AST members, $550 for non-members
- Testing provider: PSI computer-based testing centers
Test-day rules are strict: no textbooks, notes, study materials, personal electronics, or personal items are permitted in the testing room. Scratch paper is provided by the testing center and must be returned before you leave - nothing you write down can leave the room with you. If cost and budgeting are part of your planning, the CSFA Certification Cost breakdown walks through every fee in detail, including what to expect at renewal.
Turning Domain Weighting Into a Study Schedule
Once you know the weighting - 55% Perioperative Care, 31% Basic Science, 14% Ancillary Duties - the logical move is to allocate study time proportionally rather than splitting your calendar into equal thirds. A schedule that mirrors the blueprint looks something like this:
Basic Science Foundation
- Review anatomy and physiology by system
- Cover microbiology and infection control principles
- Build pharmacology recall for anesthesia and hemostasis agents
Perioperative Care Deep Dive
- Study intraoperative technique across surgical specialties
- Drill hemostasis and wound closure scenarios
- Work through pre- and post-operative decision-making cases
Ancillary Duties and Integration
- Review documentation, equipment care, and professional standards
- Run full-length timed practice sets covering all three domains
- Identify remaining weak areas and revisit targeted content
Note that spaced repetition applied to flashcards works particularly well for the dense terminology in Basic Science, while scenario-based practice questions are more effective for reinforcing Perioperative Care judgment calls. For a full domain-by-domain study system with weekly checkpoints, see the CSFA Study Guide for passing on your first attempt, and for a sense of what the actual test questions look like, review Best CSFA Practice Questions: What to Expect on the Exam.
Who Hires Based on These Domains
The domain weighting isn't just an academic exercise - it mirrors what employers expect a CSFA to do on day one. Hospitals, ambulatory surgery centers, and surgeon groups hire CSFAs specifically because of their demonstrated competency in Perioperative Care tasks like tissue handling and hemostasis, backed by the scientific reasoning tested in Basic Science.
If you're evaluating whether the credential translates into job opportunities, browsing current CSFA job listings and typical employer requirements can clarify how directly the exam content maps to daily responsibilities. And if you're still weighing the investment of time and money against the career outcome, Is the CSFA Certification Worth It? Complete ROI Analysis and the CSFA Salary Guide both address that question using available data.
For candidates who are earlier in the research process, background resources like What Is CSFA?, CSFA Meaning, and What Is CSFA Certification? explain the credential itself, while CSFA Training covers the accredited program pathway required before you're eligible to test.
Key Takeaway
Practicing with realistic, domain-weighted questions on our CSFA practice test platform is one of the fastest ways to see which of the three domains needs more attention before exam day.
Frequently Asked Questions
Many candidates start with Basic Science because it builds the anatomical and pharmacological foundation that Perioperative Care questions rely on. Since Perioperative Care carries 55% of the exam weight, plan to spend the largest block of total study time there.
Based on the 150 scored questions, Perioperative Care (55%) accounts for roughly 82 questions, Basic Science (31%) for about 46, and Ancillary Duties (14%) for around 21. Exact counts can vary slightly by exam form.
No. It's the smallest domain, but 14% still represents around 21 scored questions on a passing threshold of 99. Given how compact the content is, it's an efficient area to fully master rather than skip.
No. Of the 175 total questions, only 150 are scored; 25 are unscored pretest items used by NBSTSA for future exams. You cannot identify which questions are unscored, so treat all 175 as if they count.
You need 99 correct answers out of the 150 scored questions. The 2025 national first-take pass rate was 62%, which reflects how demanding the full blueprint across all three domains can be. For more context on pass rate trends, see the CSFA Pass Rate data breakdown.