UHM Pass Rate 2026: What the Data Shows

Is There an Official UHM Pass Rate?

Anyone searching for a specific pass-rate percentage for the AOA Subspecialty Certification in Undersea and Hyperbaric Medicine will come up empty. The American Osteopathic Conjoint Undersea & Hyperbaric Medicine Examination Committee does not publish a public pass-rate figure for its written examination, and there is no independently verified statistic circulating for 2026 or any prior cycle. This is a smaller, more specialized subspecialty pathway than many higher-volume board exams, and low candidate volume alone makes a published, statistically meaningful pass rate unlikely to appear on the official page.

That absence of a headline number is actually useful information. Instead of chasing a statistic that doesn't exist, candidates get more value from understanding the structural facts that are published: question count, scoring scale, domain weighting, and eligibility requirements. Those are the real "data" that determine whether an individual candidate passes, and they're the focus of this article.

What the Available Data Actually Shows

Rather than a pass-rate percentage, the AOA discloses the mechanics that determine outcomes: a 150-question multiple-choice format, a passing threshold of 500 on a 200-800 scaled score, and a four-category content outline with published weights. Together, these mechanics function as a more reliable planning tool than a single pass-rate number ever could, because they tell you exactly where points are concentrated and what threshold you need to clear.

For a deeper breakdown of how those weights translate into study priorities, see the UHM Exam Domains 2026: Complete Guide to All 4 Content Areas. If your goal is simply to understand what "passing" requires numerically, the UHM Passing Score 2026: Exactly What You Need to Pass guide walks through the scaled-score system in more detail.

Scoring Mechanics: The 500 Scaled-Score Threshold

The exam uses 150 multiple-choice questions and a 200-800 scaled scoring system, with 500 as the minimum passing score. A scaled score is not a raw percentage of questions answered correctly - it's a converted value that accounts for item difficulty across the specific form a candidate receives. This matters practically: two candidates who each miss a different set of 30 questions may not receive identical scaled scores, because not all items carry equal statistical weight in the scaling formula.

What this means for preparation is straightforward. You are not trying to memorize a percentage target like "70% correct." You're trying to build broad, reliable command of content across all four categories so that your raw performance comfortably clears the 500 threshold regardless of which specific items appear on your form. Candidates who cram narrowly in one domain and skip another expose themselves to scaled-score volatility they can't predict in advance.

Domain Weighting and Why It Predicts Difficulty

With 150 questions split across four categories, the weights translate into roughly 60 questions on Fundamentals, roughly 46 on Diving medicine, roughly 40 on Clinical hyperbaric medicine, and roughly 5 on Research. That distribution is the single most important piece of "data" a candidate has, because it tells you where the exam actually lives.

Fundamentals and Diving medicine together account for over 70% of the exam. If a candidate's clinical background leans heavily toward hyperbaric wound-care practice - which is common for physicians coming out of a fellowship focused on chamber operations and treatment protocols rather than dive physiology - that candidate has an exposure gap on the two largest categories combined. This is one of the more counterintuitive facts in exam planning: the domain that feels most "clinical" and familiar (Clinical hyperbaric medicine) is actually the third-largest, not the largest, share of the test.

Research, by contrast, is only 3% of the exam - roughly five questions. It still needs baseline competence, but it is not where study hours should be concentrated relative to its weight. For a category-by-category breakdown of what each domain actually tests, the UHM exam domains guide is the most direct resource, and for an honest read on how demanding the exam is overall given this weighting, see How Hard Is the UHM Exam? Complete Difficulty Guide 2026.

Eligibility Friction: Where Candidates Stall Before They Even Sit

Outcome "data" for this certification isn't limited to what happens during the exam. A meaningful share of candidates who fail to earn certification never fail the written test at all - they stall in the eligibility and application phase. The published requirements are specific and documentation-heavy:

• A COCA-accredited osteopathic medical degree
• A one-year AOA-approved internship
• A one-year AOA- or ACGME-approved hyperbaric medicine fellowship
• Primary certification through AOBEM, AOBFP, AOBIM, or AOBPM
• Unrestricted medical licensure and good ethical standing
• Documented supervision of at least 500 treatments distributed across the 13 published treatment indications, based on institutional case frequency

That 500-treatment, 13-indication requirement is the piece most likely to trip up a candidate late in the process, because it depends on institutional case mix rather than personal effort alone. A candidate at a lower-volume chamber may need extra time to accumulate the full distribution across all 13 indications, and this should be planned for well before the application deadline - not discovered when compiling the CV and fellowship documentation. The full checklist is covered in the UHM Requirements 2026: Eligibility, Prerequisites & How to Qualify guide.

Fee and Registration Mechanics That Affect Outcomes

The published examination fee and the recertification fee are each $1,100. Because this is a conjoint, relatively low-volume subspecialty pathway, candidates should confirm current registration windows directly rather than assume a recurring annual calendar - the official written-examination page has previously retained scheduling text from an earlier cycle, so an old exam date should never be treated as a confirmed 2026 appointment. For a breakdown of how the fee structure fits into the total cost of pursuing this credential, see UHM Certification Cost 2026: Complete Pricing Breakdown, and check UHM Exam Dates 2026: Testing Windows, Deadlines & Scheduling before finalizing a study plan around a specific date.

Beyond the initial exam, the certification is maintained through the AOA's Osteopathic Continuous Certification (OCC) pathway, which uses a written recertification assessment on a 10-year cycle. There is no UHM-specific CME requirement layered on top - the conjoint committee expects candidates to maintain primary-board CME and OCC compliance along with active licensure. That's a meaningfully lighter ongoing burden than credentials that impose separate specialty-specific CME tracking, and it's worth factoring into a long-term view of whether the certification is worth pursuing, discussed further in Is the UHM Certification Worth It? Complete ROI Analysis 2026.

A Domain-Weighted Preparation Timeline

Generic study techniques - spaced repetition, timed question blocks, active recall - work fine here, but they only produce results when scheduled against the actual weight distribution rather than an arbitrary calendar. Because Fundamentals and Diving medicine combine for over 70% of the test, they should anchor the first two-thirds of any study plan, with Clinical hyperbaric medicine reviewed on a rolling basis and Research handled in short, low-intensity sessions given its 3% weight.

For a structured walkthrough of this kind of plan, the UHM Study Guide 2026: How to Pass on Your First Attempt expands each week into specific study actions, and a condensed reference for last-week review is available in the UHM Cheat Sheet 2026: One-Page Review of Must-Know Facts. Timed, domain-weighted practice sets on the main practice test platform are one of the more direct ways to rehearse scaled-scoring pressure before exam day, since untimed review alone doesn't replicate how the 150-question format actually feels under a clock.

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