Orthopedic Surgery Passing Score 2026: Exactly What You Need to Pass

The Number That Matters: 500

If you're preparing for the AOBOS Part I Written Exam, one number should anchor your entire study plan: 500. That's the passing score on the 200-800 scaled-score range used for Certification in Orthopedic Surgery's initial written examination. Everything else - the domain percentages, the question count, the timing - exists to help you understand how that single number gets calculated and what it takes to clear it.

This site is focused specifically on the AOBOS Part I Written Exam for initial certification, not the AOBOS longitudinal assessment used for Osteopathic Continuous Certification (OCC) renewal, and not a different credential's examination that happens to share a similar acronym. If you've seen conflicting numbers elsewhere online, they likely belong to a different exam entirely. For a full breakdown of who's eligible to sit for this exam in the first place, see our Orthopedic Surgery Requirements guide.

Why the Score Is Scaled, Not Raw

A scaled score isn't the same as a percentage. You won't pass by answering "500 out of 800" questions correctly, and you won't fail by missing a specific number of items on a fixed 100-point scale. Instead, AOBOS converts raw performance on the 250-question exam into a standardized score that accounts for item difficulty and exam form. That's why candidates and prep resources often struggle to give an exact "number of questions you can miss" - the honest answer is that it depends on which questions those are and how the specific form is calibrated.

What you can control is your overall command of the ten written-exam domains. The scaling exists to keep pass/fail decisions consistent across different exam forms and years - it does not exist to make the bar arbitrarily higher or lower. Treat 500 as a real, fixed target, but understand that hitting it requires broad competency, not narrow test-taking tricks.

How Domain Weighting Affects Your Score

Because your final score is a composite across ten content domains, not all material contributes equally. AOBOS publishes official percentage ranges for each domain, and those ranges should guide how you allocate study time - not an even split across all ten areas. For the complete breakdown of what's tested in each domain, see our Orthopedic Surgery Exam Domains Guide.

Basic Science, Joint, and Trauma together can account for well over a third of the exam. Missing depth in any of these three has an outsized effect on whether your scaled score lands above or below 500.

Exam Format and What You're Scored On

The Part I Written Exam consists of 250 multiple-choice questions split into three sections of 120 minutes each - six hours of active testing time. Candidates can also take two optional 15-minute breaks, bringing the total session to six hours 30 minutes including breaks. That's a long day, and pacing matters as much as content knowledge.

The exam is remotely proctored under AOA MonitorEDU/PARADIGM arrangements. You'll need a private testing room, a compatible computer and mobile device, the secure browser installed, and completed technical checks before test day. AOBOS permits use of a physical whiteboard during the exam, and the platform itself supplies an online calculator, a scratch pad, and laboratory values - so you don't need to memorize normal lab ranges the way you might for a paper exam.

Because the test is split into three timed sections rather than one continuous block, section-level pacing practice matters. Running out of time in section one because you lingered on Basic Science questions can bleed into how rushed you feel entering Joint or Trauma-heavy stretches later in the exam. For a deeper look at how the exam's structure affects perceived difficulty, read How Hard Is the Orthopedic Surgery Exam?

Fees, Eligibility, and What They Don't Tell You

The written exam fee is $1,000. First-time AOAO resident members can request a $500 coupon discount, cutting their written exam fee to $500. This is separate and distinct from the Clinical Exam, which costs $2,250 and carries its own $250 late fee after its first deadline - those Clinical Exam fees are not part of Part I. All figures are in USD. For a complete pricing picture across the whole certification pathway, see our Orthopedic Surgery Certification Cost breakdown.

Eligibility for Part I includes 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). Candidates must also satisfy AOBOS's application and ethics requirements. 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 written exam itself is administered annually during the second week of May. Full scheduling details, including how the deadlines interact with the testing window, are covered in our Orthopedic Surgery Exam Dates guide.

It's worth understanding how AOBOS's Part I fits into the broader picture of orthopedic surgery credentialing, since candidates frequently compare pathways. Our Orthopedic Surgery Certification overview and What Is Orthopedic Surgery Certification? pages walk through the full certification process, including how the Clinical Exam and AOA approval complete the pathway after Part I.

Where to Put Your Study Hours

Given the domain weighting, a study plan that treats all ten domains equally is working against the scoring structure. A more efficient approach front-loads Basic Science, Joint, and Trauma early - while there's still time to revisit weak areas - and treats Tumor and Infection as focused, late-stage review rather than early deep dives.

A structured, spaced-repetition approach across these weeks works well specifically because Basic Science underlies so many later-domain questions - reviewing it early means later domains reinforce rather than compete with it. For a more complete walkthrough of study methodology tailored to this exam, see our Orthopedic Surgery Study Guide, and practice with realistic timed question sets on our practice test platform.

The Passing Score Doesn't End at Part I

Clearing 500 on the Part I Written Exam is a major milestone, but it's not the finish line. Full certification also requires the Clinical Exam - which includes surgical-practice documentation and oral defense of selected cases - followed by AOA approval. That's a separate cost structure ($2,250, plus a $250 late fee after the first deadline) and a separate evaluation format entirely from the written multiple-choice exam.

Once certified, diplomates enter Osteopathic Continuous Certification (OCC), which requires active licensure, continuing medical education, 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. The traditional ten-year high-stakes recertification exam was replaced in 2021 by an annual longitudinal assessment: 15 untimed, open-book, article-based questions drawn from three of nine assessment areas (distinct from the ten initial written-exam domains), available each year between May and July, costing $230 annually. 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 weighing whether the full certification pathway - Part I, Clinical Exam, and ongoing OCC - is worth the investment relative to career outcomes, our ROI analysis and salary guide dig into that question in more depth. And if you're still confirming that this is the right credential for your career stage, start with What Is Orthopedic Surgery? or Orthopedic Surgery Meaning for foundational context, or check Orthopedic Surgery Jobs to see how certification connects to hiring. For pass-rate context specific to this exam, see our Orthopedic Surgery Pass Rate breakdown, and run through condensed review material on the Orthopedic Surgery Cheat Sheet as exam day approaches. You can also build timed practice reps directly on the main practice test site before you sit for the real thing.

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