Written Exam


The following training requirements must be completed before a candidate may sit for the Written Exam for primary board certification in Cardiothoracic Surgery:

  • Complete four years of training in an AOA-approved residency program in General Surgery.
  • Complete two years of training in an AOA-approved residency program in Cardiothoracic Surgery.
  • Demonstrate eligibility for examination in any other manner required by the board.


Once training requirements for eligibility are met, candidates must submit the following:

  • A completed application.
  • Required fees.
  • Applicants who have not completed their training must submit a letter from their Program Director verifying the completion date of an AOA-approved residency training program.
  • All required application documents and materials must be submitted, reviewed and approved two weeks (14 days) prior to the exam administration date.

Exam Fees

An exam fee of $1,500 must be submitted with your completed application. No application will be considered complete until all fees have been paid.

All cancellations must be made in writing. Exam cancellations received 30 days or more prior to the first day of the exam administration date will be refunded less a $500 cancellation fee. No refunds will be issued for any cancellations that are received less than 30 days before the first day of the exam administration date.

Exam Dates and Deadlines

The Written Exam is offered annually in April via a remote proctoring platform. The application period opens six months prior to the exam.

Exam Content Outline

The AOBS written exam consists of 200 multiple-choice questions that tests the knowledge and understanding of basic science and clinical knowledge, skills and principles critical to the practice of Cardiothoracic Surgery. The examination is subjected to conventional psychometric analysis using accepted modern methods of key validation and item scoring. The total examination time is 4 hours and 30 minutes and is administered via a remote proctoring platform.

The exam evaluates academic knowledge in the following areas:

Primary Certification
  1. 1. Basic Science
  2. 2. Cardiac & Cardiac Surgery
  3. 3. Chest
  4. 4. Esophagus
  5. 5. Mediastinal (Mediastinum)
  6. 6. Osteopathic Manipulative Medicine
  7. 7. Other
  8. 8. Pulmonary
  9. 9. Thoracic
  10. 10. Trauma
  • 1 – 3%
  • 49 – 53%
  • 1 – 5%
  • 2 – 5%
  • 1 – 4%
  • 1 – 3%
  • 6 – 8%
  • 2 – 6%
  • 23 – 27%
  • 1 – 3%

Exam Scoring

Scoring Criteria

AOA reports candidates’ certification results using standardized scaled scores. Scaled scores are more valid and reliable compared to raw scores and make scores comparable across different forms of the exam. The AOA reports scores on a 200 to 800-point scale with a scaled score of 500 or higher required to pass.

  • A scaled score of 500 represents the minimum level of knowledge and skill necessary to pass the exam as established by AOA Certifying Boards.
  • The highest possible scaled score is 800.
  • The lowest possible scaled score is 200.
  • Overall scores are based on the total number of items answered correctly, regardless of content area.

Results by Content Area

  • When possible, a breakdown of exam scores by content area is provided to help you identify your areas of strength and areas that may need more development.
  • The number of items for each content area indicates the relative amount of test questions on the exam for that content area.
  • Content area scores are not weighted to calculate your overall score; each content area is scored separately after the overall analysis is complete.

Exam Failure

Following an initial or second failure of the AOBS Written Exam, the following rules apply:

  • The candidate may apply for re-examination and pay the required fees.
  • The candidate must re-take the exam within a two-year period following the initial or second failure. If the candidate fails to take the exam within this period, the candidate’s file will be considered inactive. Any further applications shall be considered new actions at the discretion of the board.

Following a third failure in the written qualifying and/or oral certifying examination, the candidate may apply for reexamination upon successful completion of a board review course. The applicant must provide documentation of course completion prior to retaking the written examination. Remediation does not guarantee passage of the examination process.