CHS Pass Rate 2026: What the Data Shows

What the 2025 CHS Pass Rate Numbers Actually Show

The American Board of Thoracic Surgery publishes examination statistics for its Congenital Cardiac Surgery subspecialty certification - the credential this site refers to as CHS. For 2025, ABTS reported 7 passes among 8 written examinees and 4 passes among 4 oral examinees. Those are the only concrete figures currently available from the board for this specific certification, and they should anchor everything else you read about CHS pass rates, including on this page.

There is no publicly reported multi-year trend line, no breakdown by training pathway, and no domain-by-domain performance data. If you see a source citing a precise long-run percentage for CHS, treat it skeptically unless it links directly to ABTS's own statistics page. Our companion piece on the exact passing score mechanics goes deeper into how the written and oral results are scored individually.

Why Small Cohort Sizes Change How You Read the Data

Unlike large general board exams that certify hundreds of candidates annually, CHS draws from an extremely narrow applicant pool: surgeons who have already completed primary ABTS certification, finished a qualifying congenital cardiac surgery fellowship, and secured program endorsement. That funnel means annual cohorts are measured in single digits, not hundreds.

With only 8 written examinees reported in 2025, one additional pass or fail changes the reported rate by a large margin. This is fundamentally different from interpreting pass rates on high-volume exams, and it's a key reason generic "average pass rate" commentary doesn't transfer well to this credential. If you're trying to gauge how difficult the exam actually is relative to your own preparation, our CHS difficulty breakdown unpacks this distinction in more detail.

Written Exam vs. Oral Exam: Two Different Hurdles

CHS certification is a two-part sequence, and each part is scored and reported separately. Part I is a written multiple-choice examination administered at Pearson Professional Testing Centers. You must pass the written examination before you're eligible to sit for Part II, the in-person oral examination.

The oral exam is case-based and evaluates real-time clinical reasoning, not just recall - which is why ABTS reports oral results as a distinct statistic from written results. In 2025, all four oral examinees passed, but note that oral candidates are, by definition, a pre-filtered group: they already cleared the written exam. That selection effect is worth keeping in mind rather than assuming oral success rates predict your written outcome, or vice versa.

For a fuller walkthrough of eligibility gates that determine who even reaches these numbers, see CHS Requirements 2026.

The 11 Content Domains Behind Every Written Question

Every written item on the Part I exam maps to one of eleven congenital cardiac surgery content categories drawn from the ABTS Booklet of Information. Understanding these domains - not just memorizing a list - is the single highest-leverage activity for moving your odds in the right direction, given how thin the published pass-rate data is to lean on otherwise.

The remaining domains - venous connection anomalies, tricuspid/mitral disease, left and right outflow tract anomalies, myocardial disease, perioperative management, and acquired pediatric cardiovascular disease - round out the full scope. Every category is unweighted, meaning no single domain is officially declared more heavily tested than another, so uneven preparation across domains is a real risk. Our complete guide to all 11 content areas breaks each one down further.

Question Format Changes for 2026

Starting in 2025, the written multiple-choice questions moved to a three-answer-option format. This is a meaningful shift from a standard four- or five-option format: fewer distractors per item change both the guessing math and how sharply written questions can discriminate between close clinical answer choices.

Registration Fees and Timeline That Shape Your Prep Window

Initial CHS certification carries total fees of $4,900, broken into a $650 application fee, a $1,750 written examination fee, and a $2,500 oral examination fee - before any travel or preparation expenses. Because the fee is substantial and non-trivial to repeat, most candidates treat each administration as a single, well-prepared attempt rather than a low-stakes trial run.

The 2026 written examination window runs December 7-11, 2026, with the corresponding oral examination scheduled June 4-5, 2027 in Dallas. That roughly six-month gap between passing the written exam and sitting for the oral exam is itself a planning variable: candidates need to sustain case-based reasoning skills over that interval, not just cram once and coast. For the full fee breakdown and how it compares across the certification lifecycle, see CHS Certification Cost 2026, and for the complete testing calendar see CHS Exam Dates 2026.

Who's Sitting for This Exam - and Why It Matters

Eligibility for CHS is tightly gated: candidates need current primary ABTS certification, unrestricted medical licensure, qualifying thoracic and congenital cardiac surgery training, verified operative case volume, and formal program endorsement. Fellows who started training on or after July 1, 2023 must complete two consecutive years in a single ACGME-accredited program and log at least 150 major congenital cases, with a minimum of 50 in the first year alone.

This means the population sitting for CHS each year has already cleared substantial clinical and administrative hurdles before ever opening a study guide. It's a self-selected group of trained congenital cardiac surgeons, which is part of why interpreting the pass rate as a measure of "exam difficulty" in isolation can be misleading - the candidates themselves are highly qualified going in, yet the exam still tests depth across all 11 domains rigorously.

Employers hiring for congenital and pediatric cardiac surgery roles typically expect or strongly prefer this certification once a surgeon is fellowship-trained; it functions as a subspecialty credential layered on top of primary thoracic surgery certification, rather than a general-practice checkbox. If you're weighing whether pursuing it makes sense for your career trajectory, Is the CHS Certification Worth It? examines that question directly, and CHS Jobs looks at where the credential shows up in hiring criteria.

Building a Study Plan Around the Data, Not Against It

Given how sparse the published statistics are, the more productive move is to build your preparation around domain coverage and question format rather than chasing a percentage. A structured timeline that front-loads the densest domains - conotruncal anomalies, univentricular pathways, and outflow tract anomalies - while leaving review weeks for perioperative management and acquired disease tends to work well against the 11-domain structure.

For a more granular week-by-week methodology tailored specifically to first-attempt success, see CHS Study Guide 2026: How to Pass on Your First Attempt. And if you want a compact reference for last-mile review, the CHS Cheat Sheet 2026 condenses must-know facts into a single page. You can also work through timed, domain-organized practice questions on our main practice test platform to build familiarity with the three-option format before test day.

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