- EM here refers to the AOBEM Emergency Medicine Part I Written Exam, not the CORE assessment or any other credential.
- The written exam has 300 questions across six 50-question, 60-minute sections - six hours of active testing.
- Abdominal/GI and Cardiovascular disorders each carry 9% weight, the largest of the 18 domains.
- Passing requires a scaled score of 500 on a 200-800 range; the written exam fee is $1,100.
What Is A EM, Exactly?
When people ask "what is a EM?" in the context of this site, they mean one specific credential: the Certification in Osteopathic Emergency Medicine, administered by the American Osteopathic Board of Emergency Medicine (AOBEM). This is a distinct pathway from other credentials that also use the letters "EM," and the facts, fees, and structure discussed here apply only to the AOBEM process. If you've landed on this page from a search for a different "EM," this article - and the rest of the What Is EM? and EM Meaning guides on this site - are all scoped to the osteopathic emergency medicine pathway.
Specifically, EM Exam Prep's content focuses on the Emergency Medicine Part I Written Exam, the initial knowledge assessment osteopathic emergency physicians must pass on the road to board certification. It is separate from the Part II Oral Exam and from CORE, the annual continuing-certification process that replaced the old ten-year recertification exam.
Who Issues This Credential
The AOBEM certification process sits within the broader American Osteopathic Association (AOA) certification system. Full certification is not granted after a single test - it requires completion of both the Part I Written Exam and the Part II Oral Exam, plus AOA approval. Candidates may take the written and oral exams in either order once each exam's own eligibility conditions are met, but residency training must be fully complete before sitting the oral exam.
For a deeper walk-through of who is eligible and when, see EM Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Exam Format and Delivery
The written exam is built from 300 multiple-choice questions, typically one-best-answer items with five answer options. The exam is broken into six sections of 50 questions each, with 60 minutes allotted per section - six hours of active testing time in total. That total excludes the optional 10-minute breaks between sections and an optional 40-minute lunch break after Section 3.
- Once a section closes, you cannot return to it - there is no going back to revisit earlier questions after time expires or you submit.
- Electronics and study materials are prohibited during any break, including the lunch break.
- Delivery is remotely proctored using AOA's MonitorEDU/PARADIGM arrangements, requiring a secure browser, a compatible computer plus a second mobile device, and a private, distraction-free testing space.
Because the section-locking rule removes any chance to "come back to it later," pacing within each 50-question, 60-minute block matters more than overall exam pacing. A deep dive into what makes this format demanding is covered in How Hard Is the EM Exam? Complete Difficulty Guide 2026.
Key Takeaway
Treat each 50-question section as its own mini-exam with its own 60-minute clock - you cannot borrow time from a later section or revisit a closed one.
The 18 Content Domains
AOBEM's initial written exam blueprint spreads content across 18 domains that sum to 100% of the exam. Unlike an ABEM or CORE outline, this is the specific blueprint for the initial Part I Written Exam, and it's the one you should build your study plan around.
| Domain | Weight |
|---|---|
| Abdominal and gastrointestinal disorders | 9% |
| Cardiovascular disorders | 9% |
| Traumatic disorders | 8% |
| Systemic infectious disorders | 7% |
| Nervous system disorders | 7% |
| Thoracic-respiratory disorders | 7% |
| Obstetrics and gynecology disorders | 6% |
| Procedures/skills | 6% |
| Endocrine, metabolic and nutritional disorders | 5% |
| Head, ear, nose and throat disorders | 5% |
| Musculoskeletal disorders (nontraumatic) | 5% |
| Renal and urogenital disorders | 5% |
| Toxicological disorders/clinical pharmacology | 5% |
| Environmental disorders | 4% |
| Psychobehavioral disorders | 4% |
| Systemic infectious disorders | 7% |
| Cutaneous disorders | 3% |
| Hematologic and immune system disorders | 3% |
| EMS, disaster medicine and administrative aspects of emergency medicine | 2% |
Abdominal and Gastrointestinal Disorders (9%)
Tied for the single largest domain, this area demands fluency in acute abdomen presentations, GI bleeds, hepatobiliary emergencies, and bowel obstruction patterns.
- Prioritize this domain early given its 9% weight
- Pair with Cardiovascular disorders since both carry equal, top-tier weight
Cardiovascular Disorders (9%)
The other largest domain covers acute coronary syndromes, dysrhythmias, heart failure, and vascular emergencies - core emergency-department bread-and-butter content.
- Expect dense EKG-interpretation reasoning embedded in vignette-style questions
- Review alongside Thoracic-respiratory disorders given overlapping chest-complaint presentations
Traumatic Disorders (8%)
The third-largest domain, trauma spans multisystem injury assessment, resuscitation sequencing, and procedural decision-making under time pressure.
- Connect this domain to Procedures/skills (6%), since trauma scenarios often test procedural knowledge together
For domain-by-domain breakdowns of every high-value topic across all 18 areas, see the EM Exam Domains 2026: Complete Guide to All 18 Content Areas.
Eligibility and Timeline
To sit the written exam, candidates need approved emergency-medicine residency training along with the required licensing documentation and professional/ethical compliance. AOBEM's written-exam eligibility guidance describes both graduates and final-year residents as eligible applicants, and the certification timeline allows the written exam to be taken once a candidate has completed at least 80% of residency training.
Because the written and oral exams can be sequenced flexibly (subject to each one's own eligibility rules), some candidates sit the written exam while still finishing their final year of residency, then complete the oral exam after residency is fully done. Full details on prerequisites live in EM Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Fees, Scoring, and Dates
The written examination fee is $1,100 USD. The separate Part II Oral Exam carries its own fee of $800 USD. These are independent payments tied to independent exams, not a single bundled certification fee.
Scoring uses a 200-800 scaled-score range**, with a passing score of 500. AOBEM publishes a 93.63% pass rate, but that figure is a five-year aggregate for first-time board-eligible examinees - it is not a single-year snapshot, so don't read it as "this year's" pass rate. For more context on how that number is calculated and what it actually implies for your odds, see EM Pass Rate 2026: What the Data Shows.
The next announced written exam window is March 22-24, 2027. For the full testing calendar and registration deadlines, check EM Exam Dates 2026: Testing Windows, Deadlines & Scheduling, and for the complete cost breakdown across both exam stages, see EM Certification Cost 2026: Complete Pricing Breakdown.
After Certification: OCC and CORE
Passing the written exam is the beginning, not the end. Once fully certified, physicians enter Osteopathic Continuous Certification (OCC), which requires active licensure, 60 CME credits per three-year cycle, participation in CORE, and two practice-performance improvement projects spread across a ten-year period (one project in each five-year half).
CORE - the Continuing Osteopathic Recertification Examination pathway - replaces the old ten-year, high-stakes recertification exam. New certificants enter this annual pathway rather than facing a single decade-defining re-test. CORE consists of two required core modules plus four selected article modules, totaling 40-60 questions. Unlike the Part I Written Exam, CORE is open-book**, requires a 75% score on each module, and allows two attempts separated by one week if the first attempt doesn't pass.
The annual OCC fee is $210, which includes CORE participation, with completion due by December 1 each year. It's worth repeating: none of CORE's open-book or retry allowances apply to the initial written exam - that exam is closed-book, remotely proctored, and section-locked.
Key Takeaway
Don't confuse CORE's open-book, retry-friendly annual format with the Part I Written Exam's closed-book, section-locked, one-shot structure - they are governed by completely different rules.
Building an EM-Specific Study Plan
Generic study techniques like spaced repetition or interleaved practice only help if they're mapped onto this exam's actual weight distribution. A simple way to sequence preparation: spend early weeks on the heaviest domains, then taper into lighter-weight domains as exam day approaches.
Highest-Weight Core
- Abdominal/GI disorders (9%) and Cardiovascular disorders (9%)
- Build vignette-recognition speed for these two domains first since they carry the most combined weight
Trauma and Systems
- Traumatic disorders (8%), Systemic infectious disorders (7%), Nervous system disorders (7%), Thoracic-respiratory disorders (7%)
Mid-Weight Rotation
- OB/GYN disorders (6%), Procedures/skills (6%), Endocrine/metabolic (5%), HEENT (5%), Musculoskeletal nontraumatic (5%), Renal/urogenital (5%), Toxicology/clinical pharmacology (5%)
Lower-Weight Cleanup
- Environmental disorders (4%), Psychobehavioral disorders (4%), Cutaneous disorders (3%), Hematologic/immune (3%), EMS/disaster/admin (2%)
Timed Section Drills
- Practice full 50-question, 60-minute blocks to simulate the section-locking format
- Rehearse break-timing decisions (10-minute breaks, optional 40-minute lunch after Section 3)
For a fully worked-out plan with more granular weekly tasks, see the EM Study Guide 2026: How to Pass on Your First Attempt, and for a compact one-page reference to keep nearby during final review, use the EM Cheat Sheet 2026: One-Page Review of Must-Know Facts. Working through timed practice sets on our practice test platform before exam day is one of the most direct ways to get comfortable with the section-locked, five-option question style.
Who Actually Needs This Credential
This certification is built for osteopathic physicians pursuing board certification in emergency medicine through the AOA pathway. It matters for hiring, credentialing at hospitals and emergency departments, and long-term career mobility within osteopathic-affiliated systems. If you're weighing whether the time and fees are worth it relative to career outcomes, Is the EM Certification Worth It? Complete ROI Analysis 2026 lays out the considerations, and EM Salary Guide 2026: Complete Earnings Analysis covers earnings context. For job-market specifics, see EM Jobs and EM Training.
Curious how this pathway compares to other board routes? Start with EM Certification and What Does EM Stand For? for foundational orientation before diving into blueprint specifics. You can also browse practice questions organized by domain on the main practice site to see where your knowledge gaps sit before committing to a full study schedule.
Frequently Asked Questions
It refers specifically to the Certification in Osteopathic Emergency Medicine issued through AOBEM, with this site's content focused on the Part I Written Exam rather than CORE or the oral exam.
The exam has 300 multiple-choice questions split into six 50-question sections, each with its own 60-minute time limit, totaling six hours of active testing.
A scaled score of 500 on a 200-800 range is required to pass the written exam.
No. The written exam is the initial, closed-book, remotely proctored Part I assessment. CORE is a separate, open-book annual continuing-certification pathway with different modules, scoring, and retry rules.
Abdominal and gastrointestinal disorders and Cardiovascular disorders are tied for the largest weight at 9% each, followed by Traumatic disorders at 8%.