- CHS is the American Board of Thoracic Surgery's Congenital Cardiac Surgery subspecialty certification, not a different credential sharing the same acronym.
- Initial fees total $4,900: $650 application, $1,750 written exam, $2,500 oral exam, before travel costs.
- The 2026 written window runs December 7-11, 2026, with the oral exam June 4-5, 2027 in Dallas.
- Written questions have moved to a three-option multiple-choice format starting in 2025.
What CHS Actually Is
CHS stands for Certification in Congenital Cardiac Surgery, administered by the American Board of Thoracic Surgery (ABTS). On the ABTS website the credential is also labeled Congenital Heart Surgery, but it refers to the same subspecialty pathway: a formal, two-part assessment that confirms a surgeon has the knowledge and operative judgment to independently manage congenital cardiac disease across the full spectrum of anatomic anomalies.
This is important to state plainly because "CHS" is used by other, unrelated credentialing bodies in completely different fields. If you searched broadly and landed on facts about exam fees, testing centers, or pass rates that don't match what you read here, you were likely reading about a different certification entirely. Everything in this article is specific to the ABTS Congenital Cardiac Surgery subspecialty pathway.
CHS sits on top of general thoracic surgery certification. It is not an entry-level exam - it is a subspecialty credential that verifies a surgeon has completed dedicated congenital training and accumulated a defined volume of operative experience before ever sitting for the written exam.
Who Pursues CHS and Why
Candidates for CHS are practicing cardiothoracic surgeons who already hold current primary ABTS certification and have completed structured congenital cardiac surgery training beyond their general thoracic residency. Most are finishing or have recently finished a dedicated congenital fellowship at an ACGME-accredited program, and are seeking the credential that formally distinguishes them as congenital heart surgeons rather than general cardiothoracic surgeons who occasionally touch pediatric cases.
Because the credential requires verified operative experience and program endorsement, it functions as a professional checkpoint rather than an open-entry exam. Hospitals and academic congenital heart programs use it as a hiring and credentialing signal, which is why understanding the requirements early - well before your written exam window - matters more here than in many other certification processes. For a full breakdown of who qualifies and when, see the detailed CHS Requirements 2026: Eligibility, Prerequisites & How to Qualify guide.
The 11 Content Categories
Part I written preparation is organized around 11 content categories drawn from the ABTS Booklet of Information. These are unweighted - ABTS does not publish a percentage breakdown per category - so candidates should treat coverage as comprehensive rather than trying to guess which domains carry more questions.
Domain 1: Septal Defects
Covers atrial and ventricular septal defect anatomy, repair techniques, and associated hemodynamic considerations.
- Distinguishing defect types and their surgical approach
Domain 7: Conotruncal Anomalies
One of the more procedurally dense categories, spanning tetralogy of Fallot, truncus arteriosus, and transposition physiology.
- Staged versus primary repair decision-making
Domain 10: Pre-, Intra-, and Post-Operative Evaluation and Management of Congenital Cardiac Disease
Ties together perioperative decision-making across every anatomic category rather than a single lesion type.
- Applies across nearly every other domain, making it high-yield for review
The remaining categories - Anomalies of Venous Connection, Anomalies of the Aorta/Aortic Arch/Coronary Arteries, Anomalies of the Tricuspid and Mitral Valves, Anomalies of the Aortic Valve and Left Ventricular Outflow Tract, Anomalies of the Pulmonary Valve and Right Ventricular Outflow Tract, Anomalies of Atrioventricular Connection/Univentricular Heart/Atrial and Visceral Situs, Diseases of the Myocardium, and Acquired Cardiovascular Diseases in Infants and Children - each represent distinct anatomic or physiologic territory that deserves dedicated review time. A category-by-category breakdown with study priorities is available in the CHS Exam Domains 2026: Complete Guide to All 11 Content Areas.
Key Takeaway
Because domains are unweighted, don't skip categories that feel less "high-yield" - Diseases of the Myocardium and Acquired Cardiovascular Diseases are tested alongside the more procedurally famous conotruncal and septal defect content.
Exam Format: Part I and Part II
CHS certification runs through two sequential assessments. Part I is a written, multiple-choice examination administered at Pearson Professional Testing Centers. Starting in 2025, written questions use a three-answer-option format rather than the more traditional four- or five-option layout - a structural change worth practicing against directly, since it changes both guessing strategy and how confidently you need to know material before elimination reasoning helps.
Passing Part I is a prerequisite to sit for Part II, the oral examination. The oral exam is case-based and administered in person, testing real-time clinical reasoning rather than recall. You cannot register for or attempt the oral exam without first clearing the written component.
For 2026-2027, the written window is scheduled for December 7-11, 2026, with the corresponding oral examination held June 4-5, 2027 in Dallas. That six-month gap between written and oral is intentional runway - use it deliberately rather than treating Part I as the finish line. Full scheduling details, registration deadlines, and how the two components relate are covered in CHS Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
| Component | Format | Location | Prerequisite |
|---|---|---|---|
| Part I - Written | Multiple-choice, three answer options (2025 onward) | Pearson Professional Testing Centers | Eligibility approval |
| Part II - Oral | In-person case-based examination | Dallas (June 4-5, 2027 window) | Passing Part I |
Fees and Registration Mechanics
Initial CHS certification carries three separate fees that together total $4,900, before travel or preparation costs:
- $650 application fee
- $1,750 written examination fee (Part I)
- $2,500 oral examination fee (Part II)
These are paid in stages tied to eligibility approval and progression through Part I and Part II, not as a single upfront charge. Because the oral fee is more than double the written fee and travel to Dallas adds further cost, budgeting for the full pathway - not just the written exam - matters for financial planning. A complete cost breakdown, including how these fees compare to related expenses, is in CHS Certification Cost 2026: Complete Pricing Breakdown.
Eligibility Requirements
You cannot register for CHS simply by wanting to. ABTS requires candidates to hold current primary ABTS certification, maintain unrestricted medical licensure, complete qualifying thoracic and congenital cardiac surgery training, demonstrate verified operative experience, and secure program endorsement before an application is accepted.
For fellows who began training on or after July 1, 2023, the operative volume requirement is specific: two consecutive years in a single ACGME-accredited program, with at least 150 major congenital cases completed overall and at least 50 of those cases logged in the first year. This case-minimum structure is designed to ensure exposure is both sufficient in total volume and appropriately front-loaded rather than backloaded into the final months of training.
Key Takeaway
If your fellowship started on or after July 1, 2023, track your first-year case count against the 50-case minimum early - falling short in year one cannot simply be made up by overperforming in year two.
Building a CHS-Specific Prep Plan
Generic study techniques - spaced repetition, timed practice blocks, active recall - all apply here, but only in service of CHS's actual structure: 11 unweighted content categories, a three-option written format, and an oral exam that rewards real-time reasoning over memorized lists. A study plan that ignores that structure wastes time.
Anatomic Core Domains
- Septal Defects, Conotruncal Anomalies, and Atrioventricular Connection/Univentricular Heart anatomy and repair sequencing
Valve and Outflow Tract Domains
- Aortic valve/LVOT, pulmonary valve/RVOT, and tricuspid/mitral valve anomalies, cross-referenced against operative technique
Vascular, Myocardial, and Acquired Disease Domains
- Aorta/arch/coronary anomalies, venous connection anomalies, myocardial disease, and acquired pediatric cardiovascular disease
Perioperative Management and Timed Practice
- Domain 10 integration across cases, plus full-length timed practice under the three-option format
Because Part I must be passed before you can even register for Part II, treat the written exam as the gating event, but start reviewing oral-style case reasoning - not just recall - well before your written date. A structured week-by-week approach, including how to sequence the domains above around your clinical schedule, is laid out in the CHS Study Guide 2026: How to Pass on Your First Attempt. Practicing against realistic question formats on our practice test platform before test day can also help you get comfortable with the three-option structure specifically, rather than the four- or five-option format you may be used to from other exams.
If you're still deciding how much difficulty to expect relative to your training background, How Hard Is the CHS Exam? Complete Difficulty Guide 2026 walks through what makes both Part I and Part II demanding, and CHS Passing Score 2026: Exactly What You Need to Pass covers what "passing" actually requires.
What the 2025 Numbers Show
ABTS reported 7 passes among 8 written examinees and 4 passes among 4 oral examinees in 2025. These are very small cohorts, and ABTS itself would caution against treating a single year's numbers as a stable trend - a handful of candidates can swing the ratio significantly year to year. That said, the figures suggest that candidates who reach the point of sitting for CHS, having already cleared the eligibility bar of prior training and case volume, are generally well-prepared.
What the numbers don't tell you is how much preparation time, domain-by-domain review, or oral case practice went into those outcomes. For a fuller discussion of what small-cohort statistics can and cannot tell you about your own odds, see CHS Pass Rate 2026: What the Data Shows.
Continuing Certification After You Pass
Passing Part I and Part II does not end your relationship with ABTS requirements. Since January 2024, ABTS continuing certification uses non-time-limited certificates that remain valid conditional on meeting five-year milestone requirements, with previously issued time-limited certificates transitioning to the new structure as they expire.
Ongoing requirements include maintaining unrestricted licensure and hospital privileges, providing professional references, completing 150 Category 1 CME credits per five-year period (with at least 75 of those specifically related to thoracic surgery), demonstrating qualifying congenital case activity, completing an online continuing-certification assessment, and meeting patient-safety and quality-improvement requirements.
This structure means CHS is not a one-time exam to check off - it's an ongoing professional standard tied to your active practice. Surgeons evaluating whether the full pathway is worth pursuing, given both the initial cost and the five-year maintenance cycle, may find it useful to review Is the CHS Certification Worth It? Complete ROI Analysis 2026 alongside CHS Salary Guide 2026: Complete Earnings Analysis and CHS Jobs before committing time and fees to the application.
No. CHS is a subspecialty certification layered on top of primary ABTS certification. You must already hold current primary ABTS certification before you're eligible to apply for CHS.
No. Passing Part I, the written examination, is required before you can sit for Part II, the in-person oral examination.
Starting in 2025, written multiple-choice questions use a three-answer-option format, a change from the traditional four- or five-option layouts used in many other exams.
The two-consecutive-year, 150-case, 50-case-first-year requirement specifically applies to fellows starting on or after that date. Earlier fellows should confirm their specific eligibility pathway directly through ABTS materials.
Since January 2024, certificates are non-time-limited but remain conditional on meeting five-year milestone requirements, including CME credits, case activity, and a continuing-certification assessment.