Orthopedic Surgery Study Guide 2026: How to Pass on Your First Attempt

What the AOBOS Part I Written Exam Actually Tests

When candidates search for "AOBOS Part I" or "AOBOS written exam," they're usually trying to separate this exam from the broader certification pathway administered by the American Osteopathic Board of Orthopedic Surgery (AOBOS). This guide focuses specifically on that Part I Written Exam - the initial gatekeeping assessment, not the later Clinical Exam and not the ongoing Osteopathic Continuous Certification (OCC) process. If you're unclear on how these pieces fit together, our Orthopedic Surgery Certification overview lays out the full sequence.

The written exam is a 250-item multiple-choice test split into three 120-minute sections - six hours of active testing, plus two optional 15-minute breaks that bring the total seated time to six hours 30 minutes. That structure matters for pacing: you have roughly 1.44 minutes per question if you want to finish each section with time to review flagged items. Many candidates underestimate how much stamina this exam demands and burn their breaks too early in section one.

Eligibility, Fees, and Application Windows

AOBOS Part I eligibility requires graduation from an ACGME-accredited orthopedic surgery residency, or current standing as a PGY-4 or PGY-5 resident. PGY-4 applicants need program-director approval before they can sit for the exam. Candidates must also satisfy the board's application and ethics requirements - this isn't a purely academic hurdle. For a full breakdown of who qualifies and when, see our dedicated Orthopedic Surgery Requirements guide.

The written exam fee is $1,000. First-time AOAO resident members can request a $500 coupon discount, cutting that to $500 - a detail that's easy to miss if you're not actively enrolled in AOAO membership before applying. The separate Clinical Exam, which comes later in the certification process, costs $2,250 with a $250 late fee after its first deadline. These two fee structures are frequently confused; our Orthopedic Surgery Certification Cost breakdown keeps them separate line by line.

Applications open in October. The first deadline is the first business day in March, and the final deadline is the first business day in April. The exam itself is administered annually during the second week of May. Miss the March deadline and you're not disqualified, but you lose the earlier planning window - and given how dense the Basic Science and Trauma domains are, that lost time matters. Full scheduling detail lives in our Orthopedic Surgery Exam Dates article.

Domain-by-Domain Study Priorities

The Part I Written Exam covers ten domains with official percentage ranges that AOBOS does not normalize - meaning some content areas are simply worth more points than others, and your study hours should reflect that. Treat these ranges as a budgeting tool, not a suggestion. For the complete content map, our Orthopedic Surgery Exam Domains Guide goes deeper into each area.

The remaining six domains - Foot/Ankle (10-11%), Hand/Upper Extremity (10-12%), Pediatrics (9-11%), Spine (9-11%), Tumor (4-6%), and Infection (5-6%) - carry smaller but still meaningful weight. Tumor and Infection are the lowest-weighted domains, but they are also where candidates who skip "low-yield" review tend to lose easy points, since the tested content in these areas is narrower and more predictable.

Passing Score and Scaled Scoring Mechanics

Passing the Part I Written Exam requires a scaled score of 500 on a 200-800 range. This is not a simple percentage-correct threshold - the scale accounts for question difficulty across the ten domains, so two candidates answering the same number of questions correctly could theoretically land on different sides of 500 depending on which questions they missed. Our Orthopedic Surgery Passing Score guide walks through what that scaled range means in practice.

One statistic worth understanding correctly: the published pass rate of 98.2% is a five-year aggregate figure for first-time, board-eligible examinees - not a single-year snapshot. That distinction matters when you're calibrating how much anxiety is rational versus performative. We break down what that aggregate actually implies about difficulty in our Orthopedic Surgery Pass Rate analysis and in our companion piece on how hard the exam really is.

A Study Timeline Built Around AOBOS Weighting

Generic study techniques - spaced repetition, timed question blocks, active recall - work fine here, but only if you sequence them around AOBOS's actual domain weighting rather than an arbitrary alphabetical or textbook order. Given that applications open in October and the exam sits in the second week of May, most candidates have a six-to-seven-month runway from application to test day.

For a compact, at-a-glance version of everything above, keep our Orthopedic Surgery Cheat Sheet open during your final review weeks, and use our practice test platform to run mixed-domain question sets that mirror the real weighting instead of studying domains in isolation.

Remote Proctoring and Test-Day Logistics

The AOBOS Part I Written Exam follows AOA MonitorEDU/PARADIGM remote proctoring arrangements. You'll need a private testing room, a compatible computer and mobile device, the secure browser installed and configured in advance, and completed technical checks before test day. Do not leave the technical check until the morning of your exam - treat it as its own task with its own deadline, ideally a week ahead.

On the content side, remember that the platform itself supplies an online calculator, scratch pad, and laboratory values - you don't need to memorize reference ranges you'll have on-screen. Physical whiteboards are also permitted, which is useful for sketching fixation constructs or classification decision trees during Trauma and Joint questions.

After the Written Exam: The Path to Full Certification

Passing the Part I Written Exam is a milestone, not the finish line. Full AOBOS certification also requires the separate Clinical Exam, which includes surgical-practice documentation and an oral defense of selected cases, followed by AOA approval. That process carries its own $2,250 fee structure and timeline, distinct from everything covered here.

Once fully certified, diplomates enter Osteopathic Continuous Certification (OCC), which requires active licensure, CME, longitudinal assessment, and quality-improvement attestation. For the 2025-2027 cycle, time-limited and participating OCC diplomates need 60 CME credits, including 15 Category 1-A credits. Longitudinal assessment replaced the traditional ten-year high-stakes exam in 2021 - it now consists of 15 untimed, open-book, article-based questions drawn from three of nine assessment areas (distinct from the ten initial written-exam domains), available annually between May and July, at a cost of $230 per year. The passing requirement is 80%, with a second attempt available before the end-of-July deadline. Newly certified diplomates get one full calendar year before required assessment participation begins.

If you're still deciding whether this whole pathway is worth pursuing given the time and fee investment across Part I, the Clinical Exam, and OCC, our Is the Orthopedic Surgery Certification Worth It? analysis and Orthopedic Surgery Salary Guide are worth reading before you apply.

Frequently Asked Questions

For deeper dives into any single piece of this process - from eligibility mechanics to a domain-by-domain content map - start with our Orthopedic Surgery Study Guide hub, and run realistic, domain-weighted question sets on our practice exam platform before you sit for the real thing.