- What the Credential Actually Is
- Who Issues It and Why That Matters
- Who Can Pursue It
- The Written Stage: Format and Fees
- The Ten Content Areas and Their Weights
- The Oral Stage: Clinical Cases
- Credit for a Passed ABTS Written Exam
- Failure and Retake Rules
- Staying Certified: OCC Components
- Sequencing Your Preparation by Domain Weight
- What the Sources Do Not Settle
- Frequently Asked Questions
- This is Primary Certification in Cardiothoracic Surgery from the American Osteopathic Board of Surgery (AOBS), with AOA certification approval.
- The written exam has 200 multiple-choice questions, runs four hours 30 minutes, and costs $1,500.
- Cardiac & Cardiac Surgery is 49-53% of the written blueprint; Thoracic follows at 23-27%.
- The passing score is a scaled 500 on a 200-800 scale; the oral stage costs a separate $1,500.
What the Credential Actually Is
"A cardiothoracic surgery" in the context of this site is a specific professional credential: Primary Certification in Cardiothoracic Surgery, offered through the American Osteopathic Board of Surgery. It certifies that a surgeon trained in operations of the heart, lungs, esophagus, mediastinum and related thoracic structures has met a defined standard of knowledge and clinical judgment. It is a board certification, not a degree, a residency, or a license to practice.
The credential has two stages: a written examination and an oral examination. The written stage tests breadth of knowledge across ten content areas using multiple-choice questions. The oral stage tests how you reason through clinical cases in front of examiners. Passing both, along with meeting eligibility and documentation requirements, is how a candidate earns primary certification.
If you are looking for the broader meaning of the field itself, our overview at What Is Cardiothoracic Surgery? covers the discipline, while this article focuses on the certification and the exam behind it. For a related framing, see What Is Cardiothoracic Surgery Certification?
Who Issues It and Why That Matters
The certifying body is the American Osteopathic Board of Surgery (AOBS), operating with certification approval from the American Osteopathic Association (AOA). That detail matters because several credentials in surgery and medicine share similar names or abbreviations, and their exam fees, content outlines, dates and policies differ. Everything in this article refers to the AOBS pathway only. When you search for fees, deadlines or content outlines, confirm that the page you are reading belongs to the AOBS cardiothoracic certification and not to another board.
The official exam-objective source is the AOBS written exam content outline for cardiothoracic surgery, published on the AOA certification site. We use its ten content areas and published percentage ranges as published, without rebalancing them.
Who Can Pursue It
Eligibility rests on approved training, an active unrestricted license and required documentation. The specialty page describes a pathway of four years of AOA-approved general surgery plus two years of cardiothoracic training, with program-director documentation. Current AOBS Board Policies also recognize qualifying DO/MD and ACGME routes, so the policies page is the place to check how your own training history is treated.
Two practical points deserve emphasis:
- Licensure must be active and unrestricted. A restriction on your license can stall an otherwise complete application.
- Documentation is part of the exam. Program-director attestations and training records take time to assemble, so start gathering them early.
The Protocol for Certification document is under revision and was not retrieved as a current handbook, so treat the web pages and Board Policies as your working references. Our guide to Cardiothoracic Surgery Requirements walks through qualification steps in more detail.
The Written Stage: Format and Fees
The written exam is a single sitting with a clear structure:
| Written Exam Element | Detail |
|---|---|
| Question count | 200 multiple-choice questions |
| Time allowed | Four hours 30 minutes |
| Fee | $1,500 |
| Passing standard | Scaled score of 500 on a 200-800 scale |
| Remote delivery | Follows AOA remote-proctoring instructions, naming the MonitorEDU Secure Browser and PARADIGM testing |
Four and a half hours for 200 questions averages out to a little over a minute per item, which leaves some room for harder cases but no room for dwelling. Because the cardiac content is so heavily weighted, a single long cardiac stem can consume time you would like to spend elsewhere, so practice pacing with realistic question styles.
For remote candidates, the technical setup is part of preparation. The AOA's remote-proctored exam page names the MonitorEDU Secure Browser and PARADIGM testing, so install and test the required software well before exam day rather than discovering a compatibility problem at check-in.
A scaled score means your raw number of correct answers is converted onto a 200-800 range; 500 is the passing line. Read our explanation in Cardiothoracic Surgery Passing Score to understand what that means for how you interpret practice results. No AOBS cardiothoracic-specific pass rate was verified, so be wary of any source that quotes one with confidence. Our pass rate discussion explains what can and cannot be said.
The Ten Content Areas and Their Weights
The published outline divides the written exam into ten areas. The ranges below are quoted as published:
| Content Area | Published Range |
|---|---|
| Basic Science | 1-3% |
| Cardiac & Cardiac Surgery | 49-53% |
| Chest | 1-5% |
| Esophagus | 2-5% |
| Mediastinal (Mediastinum) | 1-4% |
| Osteopathic Manipulative Medicine | 1-3% |
| Other | 6-8% |
| Pulmonary | 2-6% |
| Thoracic | 23-27% |
| Trauma | 1-3% |
Two areas, Cardiac & Cardiac Surgery and Thoracic, together account for roughly three quarters of the exam at the midpoint of their ranges. The other eight areas share the remainder. That shape should drive how you allocate time. For a deeper walk through each area, see our complete guide to all 10 content areas.
Cardiac & Cardiac Surgery (49-53%)
The dominant area. Expect questions that probe diagnosis, operative indications, perioperative management and complications across the adult cardiac surgical spectrum.
- Indications and timing for operative intervention across common cardiac conditions
- Perioperative and postoperative management, including complication recognition
- Interpretation of investigations that drive surgical decisions
- Judgment questions where several options are defensible and one is best
Thoracic (23-27%)
The second-largest area covers surgical disease of the chest beyond the heart.
- Evaluation and staging considerations that determine operability
- Operative approach and perioperative care for thoracic procedures
- Management of postoperative complications
The Smaller Areas: Esophagus, Pulmonary, Mediastinal, Chest, Trauma
Individually small, collectively meaningful. Esophagus (2-5%), Pulmonary (2-6%), Chest (1-5%), Mediastinal (1-4%) and Trauma (1-3%) can add up to a noticeable share of questions, and they tend to reward focused review of high-yield presentations rather than broad reading.
Other, Basic Science and OMM
"Other" carries 6-8%, which makes it larger than any of the single small clinical areas. Basic Science (1-3%) and Osteopathic Manipulative Medicine (1-3%) are low-weight but easy to neglect. Because the certifying body is osteopathic, OMM appears on the blueprint even though it is a small slice; a brief, targeted refresher is cheaper than losing those points.
The Oral Stage: Clinical Cases
The oral examination costs $1,500 and uses criterion-referenced clinical cases. Examiners assess how you approach diagnosis, investigations, differential diagnosis and management. The published material does not specify an oral question count or a timer, so do not rely on figures from other boards or from anecdote.
The 2026 oral sitting was held on September 30 in person in New Orleans. Format and location can change from year to year, so confirm the current arrangements through AOBS notices and the application portal.
"Criterion-referenced" is worth understanding. Your performance is judged against a defined standard rather than against other candidates, so the goal is to demonstrate sound, safe, well-organized reasoning rather than to outperform a cohort. In practice that means rehearsing a consistent structure for any case: establish the problem, state your differential, choose investigations with a reason, then lay out management and contingencies.
Credit for a Passed ABTS Written Exam
An April 29, 2026 AOA announcement, covering new subspecialty certification in neurocritical care and an expansion of AOBS certification eligibility, recognizes a passed ABTS written examination for the AOBS cardiothoracic oral-stage application. In plain terms, a candidate who has passed the ABTS written exam can use that result toward the oral-stage application within the AOBS pathway.
It is important not to over-read this. It is credit within the selected AOBS pathway. It does not substitute an ABTS credential for AOBS certification, it does not mean the two syllabi are identical, and it carries no ABTS pass rate. Candidates who receive written-exam credit should also not assume the same fee path as standard AOBS candidates; confirm what you will owe through the portal.
Failure and Retake Rules
The written-exam page sets out how retakes work:
- Reapplication is required after a failure.
- A two-year retake window follows the first or second failure.
- Documented board-review study is required after a third written or oral failure, before another written attempt.
These rules reward a serious first attempt. Costs compound as well: with a $1,500 written fee and a $1,500 oral fee, the standard AOBS written-plus-oral total is $3,000 by simple addition, before any other costs such as travel, application items or remote-exam setup. Our certification cost breakdown discusses how to budget around those variables, and our difficulty guide helps you judge how much preparation to plan for.
Staying Certified: OCC Components
Certification is not a one-time event. The specialty timeline describes primary active status for one year, subject to Osteopathic Continuous Certification (OCC). Several components keep it current:
- Active licensure and 60 CME credits per three-year cycle. The 2025-2027 CME Requirements by Specialty Board document confirms 60 credits for time-limited and OCC participants and supersedes the older CME guide link.
- Annual longitudinal assessment of 15 questions.
- A quality improvement/quality assurance attestation every three years.
One of the OCC pages carries legacy wording about a 10-year cycle. That wording does not establish a new ten-year validity term, so do not assume your certificate is good for a decade. Follow the current OCC requirements and your portal dashboard instead.
Sequencing Your Preparation by Domain Weight
General study methods are covered in our study guide; here is the one place we tie scheduling to this blueprint. Because Cardiac & Cardiac Surgery and Thoracic carry the bulk of the exam, they deserve the bulk of your calendar, with the small areas handled in compact, high-yield passes.
Cardiac & Cardiac Surgery
- Spend the largest block here because it is 49-53% of the written exam
- Mix reading with timed multiple-choice sets to build pacing for the 200-question format
Thoracic
- Cover the 23-27% area with attention to operability and perioperative care
- Revisit cardiac weak spots in short daily reviews
Esophagus, Pulmonary, Chest, Mediastinal, Trauma
- Cover the smaller clinical areas as one connected review
Other, Basic Science, OMM and full-length practice
- Close gaps in "Other" (6-8%), then do a brief Basic Science and OMM refresher
- Take a full timed run through the 200-question format and rehearse oral case presentations
You can pressure-test this plan against realistic questions on our main practice test site, and use the one-page cheat sheet for last-week review.
What the Sources Do Not Settle
Honest preparation means knowing where the published information is inconsistent or incomplete:
- Application lead time. Specialty pages conflict on five versus six months of lead time and retain April scheduling, while the board homepage lists May 1-3, 2027 for the remote Spring Qualifying Examination. Current notices and the application portal must resolve your own deadline. See exam dates and scheduling for how we track this.
- Handbook currency. The Protocol for Certification is under revision and was not retrieved as a current handbook.
- Pass rate. No AOBS cardiothoracic-specific pass rate was verified.
- Oral format. No oral question count or timer is stated in the sources we used.
Salary and career questions are separate topics. If you are weighing whether the credential pays off, our ROI analysis and salary guide take that up directly, and cardiothoracic surgery jobs looks at the employer side. For training background, see cardiothoracic surgery training.
Key Takeaway
Verify every date, fee and eligibility detail against the live AOBS pages and your application portal before acting. The structure in this article (two stages, 200 questions, ten content areas, a 500 scaled passing score) is stable enough to plan around, but deadlines and pathway details are where candidates get caught out.
Frequently Asked Questions
Here it means Primary Certification in Cardiothoracic Surgery from the American Osteopathic Board of Surgery, with AOA certification approval. It has a written stage and an oral stage and certifies knowledge and clinical judgment in cardiothoracic surgery.
The written exam has 200 multiple-choice questions and runs four hours 30 minutes. The fee is $1,500, and the passing standard is a scaled score of 500 on a 200-800 scale.
Cardiac & Cardiac Surgery is the largest at 49-53%, followed by Thoracic at 23-27%. The remaining eight areas, including Other at 6-8%, share the rest of the exam.
It costs $1,500 and uses criterion-referenced clinical cases assessing diagnosis, investigations, differential diagnosis and management. The sources do not state a question count or timer, and the 2026 sitting was September 30 in person in New Orleans.
No. A passed ABTS written exam is recognized as credit toward the AOBS cardiothoracic oral-stage application within the AOBS pathway. It does not substitute an ABTS credential and does not imply the same syllabus or pass rate.
Through OCC: active licensure, 60 CME credits per three-year cycle, a 15-question annual longitudinal assessment, and a QI/QA attestation every three years. Legacy 10-year wording on one page does not establish a ten-year validity term.
For a broader orientation to the credential and its terminology, you can also read Cardiothoracic Surgery Certification, What Does Cardiothoracic Surgery Mean? and What Does Cardiothoracic Surgery Stand For?