CST Content Outline by Sub-Area: Where the 150 Scored Questions Come From

Every CST exam form draws its 150 scored questions from eight sub-areas in fixed numbers set by NBSTSA's content outline, effective January 1, 2023 and still current as checked on October 25, 2026. The largest by far is Intraoperative Procedures, with 68 scored items. NBSTSA's exam development guide says every form matches the outline exactly, so each candidate gets the same number of items in each area.

The 8 CST sub-areas and their scored-item counts

The item counts come from the outline and NBSTSA's certification page. The shares and task-line counts are Passy arithmetic from the outline.

The 25 unscored pretest questions come on top of these, for 175 in all. They are spread randomly through the exam and do not count.

The Basic Science task counts look small because each line bundles a list. One Anatomy and Physiology line covers the anatomy of 14 body systems, another covers the physiology of the same 14, and a third covers surgical pathologies. The first Microbiology line bundles five named topics, and the first Pharmacology line bundles four.

Full CST prep follows the same split: of its 975 planned questions, 634 are Perioperative Care, 146 Ancillary Duties and 195 Basic Science, which is 65/15/20. See how full CST prep is organized by these subject areas.

Intraoperative Procedures decides the CST exam

With 68 of the 150 scored items, Intraoperative Procedures is the one sub-area you cannot work around. Some Passy arithmetic shows why:

• If you missed every Intraoperative item, the most you could score is 82, well short of the 98 explained in the CST passing score guide.
• If you answer half of them correctly (34), you need 64 of the other 82 scored items, or 78%.
• If you answer three quarters correctly (51), you need 47 of the other 82, or 57%.

Its 29 task lines are the core of the scrub role: maintaining aseptic technique and handling breaks in it, following Standard and Universal Precautions, anticipating the steps of a procedure, performing counts with the circulator, preparing hemostatic agents, verifying and labeling medications and solutions, using sutures, needles and staplers, choosing among methods of hemostasis, preparing specimens and drains, and acting in an emergency. At about 2.3 scored items per task line, this sub-area rewards depth, and many of these lines are decisions made in sequence during a case, which scenario questions train better than lists. When full prep launches, you will be able to practice Perioperative Care scenarios one subject area at a time.

High-yield and low-yield CST sub-areas by items per task line

Dividing each sub-area's items by its task lines (Passy arithmetic) shows where a single topic is likely to be tested more than once, and where the outline is wide but thin.

Equipment Sterilization and Maintenance: 8 lines, 16 items

Two scored items per task line, close to the density of Intraoperative Procedures. The lines are concrete and include: troubleshoot equipment, decontaminate and clean instruments, pre-clean with enzymatic cleaner, inspect, test and assemble instruments, and interpret chemical and biological indicators. A short list that carries 16 items is worth learning thoroughly.

Postoperative Procedures and Administrative and Personnel: long lists, few items

Postoperative Procedures has 18 task lines for 10 items, and Administrative and Personnel has 13 lines for 7 items. NBSTSA's exam development guide says each item should measure a single objective, so on any one form at most 10 postoperative tasks and 7 administrative tasks can be the focus of a scored question. Cover every line at a working level rather than drilling one in depth. Administrative and Personnel is also where the outline puts electrical and fire safety, disaster plans, ethics and legal practice, and cultural diversity.

Preoperative Preparation: 27 lines, 19 items

Under one item per line, but the lines are the daily routine of opening a room: hand wash and surgical scrub, checking packages for sterile integrity and expiration, gowning and gloving, positioning, skin prep, draping, and the Universal Protocol time-out. If your clinical rotations drilled these steps, this sub-area is a sensible place to secure points with a quick review.

What the CST Basic Science lines actually ask

The outline frames Basic Science around surgery, not general science:

• Anatomy and Physiology (18 items). Medical terminology and abbreviations; anatomy and physiology "as they relate to the surgical procedure" for 14 systems, including ophthalmic, otorhinolaryngology and peripheral vascular; and surgical pathologies such as abnormal anatomy, disease processes, malignancies and traumatic injuries.
• Microbiology (6 items). Classification and pathogenesis of microorganisms, infection control, tissue handling (Halsted principles, traction and countertraction), wound healing, surgical wound classification, and factors that influence infection.
• Surgical Pharmacology (6 items). Anesthesia agents and complications such as malignant hyperthermia, methods of anesthesia administration, drugs and solutions such as hemostatic agents, antibiotics and IV solutions, weights, measures and conversions, and awareness of maximum doses for agents such as lidocaine (Xylocaine), bupivacaine (Marcaine), heparin and epinephrine.

Twelve items across Microbiology and Pharmacology is a small share, but dose limits and conversions come down to calculations you can practice until they are automatic.

Turning the CST outline into a study order (Passy method)

NBSTSA's free Study Evaluation has you rate yourself on each of the eight sub-areas from 1 (very knowledgeable) to 5 (not knowledgeable), and says to focus on the areas you rate 3, 4 or 5. One way to rank them, which is a Passy method and not an NBSTSA one, is to multiply each sub-area's scored items by your rating.

A worked example (fictional candidate). Jordan rates Intraoperative 3, Equipment Sterilization 4, Anatomy and Physiology 3, Pharmacology 5, Administrative 4, Preoperative 2, Postoperative 2 and Microbiology 3.

Jordan's weakest area, Pharmacology, lands fifth because it carries only 6 items, while a middling Intraoperative rating still comes first. Redo the ratings every couple of weeks; NBSTSA suggests educators have students repeat the evaluation to track progress. The free CST study planner can then spread the time across your weeks.

Official CST study materials that map to the outline

• The reference list. NBSTSA's 2025 CST Reference List names the texts its committee uses to write questions, including Alexander's Care of the Patient in Surgery (17th edition, 2022), Surgical Technology: Principles and Practice (8th edition, 2021), Pharmacology for the Surgical Technologist (6th edition, 2023) and Surgical Instrumentation: An Interactive Approach (4th edition, 2022). NBSTSA says the committee uses the most current edition of each, so check for newer ones. Its educator page adds that students do not need to buy them all.
• Sample questions. The outline PDF ends with five sample questions and their answers, a quick look at NBSTSA's style.
• Practice exams. NBSTSA's prepare page links its self-assessment practice tests and describes a new Practice Exam Hub, still marked "Coming soon" as checked on October 25, 2026.

Identifying instruments by function, application and classification is one of the Intraoperative task lines. That part of the outline is best studied with your program's instrument sets and an instrumentation reference rather than from text alone. For the recall-heavy topics that text does handle well, such as sutures, hemostatics, wound classes and maximum doses, look at the flashcards planned for CST recall topics. To check your reasoning on a few outline topics now, try the 20 free CST practice questions.