- The written component is 110 multiple-choice questions in two hours, scored on a 200-800 scale with a passing standard of at least 500.
- Six representative practical cases must be submitted before you can even sit the written component.
- Initial fee is USD 1,800; late applications add USD 540; retakes run USD 900 (one component) or USD 1,800 (both).
- The 2026 exam date is September 24, with a June 24 first deadline and July 24 final deadline.
Quick-Reference Snapshot
This cheat sheet condenses the AOBD's Subspecialty Certification in Mohs Micrographic Surgery (MMS) into a single scannable reference. It is not a substitute for the full requirements published by the certifying body, but it is exactly what you want pinned above your desk during the final stretch of preparation. For a deeper walkthrough of any single item below, see the MMS Study Guide 2026 or the domain-by-domain breakdown in the MMS Exam Domains 2026 guide.
| Item | Detail |
|---|---|
| Certifying body | American Osteopathic Board of Dermatology (AOBD) |
| Written exam length | 110 multiple-choice questions, 2 hours |
| Practical requirement | 6 submitted representative cases (oral explanation if requested) |
| Passing standard | Scaled score ≥ 500 (scale is 200-800) |
| Initial fee | USD 1,800 |
| Retake fee | USD 900 (one component) / USD 1,800 (both) |
| Late fee | USD 540 |
| 2026 exam date | September 24 |
| Application deadlines | June 24 (first), July 24 (final) |
| Certification term | 10 years, subject to OCC |
Eligibility Pathways at a Glance
Before you can register, you need active AOBD certification, current medical licensure, complete training and ethical documentation, and CLIA documentation on file. Beyond that baseline, candidates qualify through one of three routes:
- Accredited fellowship route: Completion of an AOA- or ACGME-accredited Micrographic Surgery and Dermatologic Oncology fellowship, with its associated case log.
- ASMS fellow route: Qualifying American Society for Mohs Surgery fellow status plus 500 cases performed in the preceding three years.
- Clinical pathway: 500 cases in the preceding three years, without a fellowship, available through December 31, 2028.
The clinical pathway is the one candidates most often ask about, largely because it has a hard sunset date. After December 31, 2028, an accredited fellowship becomes mandatory for all future applicants - there is no grandfathering beyond that point. If your eligibility rests on the clinical pathway, treat 2028 as a real deadline, not a distant abstraction. Full eligibility documentation details, including what counts as ethical and training documentation, are covered in the MMS Requirements 2026 guide.
Key Takeaway
If you're relying on the clinical pathway, confirm your 500-case log is current and complete well before the application window closes - missing cases or documentation gaps are the most common source of delayed applications.
Written Exam Format
The initial written component consists of 110 multiple-choice questions administered in a two-hour window. That works out to roughly one minute per question if you spend the full allotted time, but in practice most candidates find the pacing manageable if their content knowledge is solid - the real bottleneck is usually recall speed on dermatopathology and anatomy items, not the clock itself.
Because this is a subspecialty exam layered on top of existing AOBD dermatology certification, the question style assumes fluency with general dermatology and pushes deeper into Mohs-specific decision-making: tumor subtype recognition on frozen section, flap and graft selection logic, anesthesia dosing in the context of surgical duration, and complication management in real time. If you want a sense of how difficult candidates find this exam relative to other board pathways, the How Hard Is the MMS Exam? guide walks through the qualitative difficulty factors.
Practical Component: Six Cases
The practical component is easy to underestimate because it isn't a timed test - it's a submission requirement. Candidates must submit six representative cases, and the AOBD may request an oral explanation of any of them. This is where clinical judgment gets scrutinized directly rather than through multiple-choice abstraction.
If a practical retake becomes necessary, the AOBD requires three new cases - not a resubmission of the original six with corrections. This is a meaningful cost in time and case selection, so treat your original six submissions as final-draft quality, not first-draft.
The 11 Content Areas
AOBD's editorial preparation topics organize the written exam's coverage into eleven areas. No official percentage weighting is published for these, so treat any allocation you see in a practice bank as an editorial estimate rather than a guaranteed blueprint. Still, knowing the eleven areas by name lets you audit your own preparation gaps systematically.
Domain 1: Tumor Biology and Cutaneous Oncology
Underlying malignancy behavior, subtype aggressiveness, and oncologic principles that justify the Mohs approach.
- Histologic subtypes and their growth patterns
- Recurrence risk factors
Domain 2: Indications for MMS
When Mohs is the appropriate modality versus standard excision or other treatment.
- Anatomic site and tumor characteristics that favor MMS
- Contraindications and alternative approaches
Domain 3: Surgical Technique
Stage-by-stage execution, margin mapping, and tissue handling during the procedure itself.
- Debulking and staged excision logic
- Mapping and orientation accuracy
Domain 4: Surgical Anatomy
Regional anatomy relevant to safe excision and reconstruction, especially in cosmetically and functionally sensitive zones.
- Facial danger zones and nerve courses
- Vascular territories relevant to flap planning
Domain 5: Local and Regional Anesthesia
Agent selection, dosing limits, and technique for prolonged multi-stage procedures.
- Maximum dosing in extended cases
- Regional nerve block application
Domain 6: Preoperative Evaluation
Risk stratification, medication management, and patient selection before the first stage begins.
- Anticoagulant management decisions
- Comorbidity-driven planning
Domain 7: Histological Technique
Frozen section processing accuracy - arguably the most distinctive technical skill tested relative to general dermatology exams.
- Tissue processing and staining pitfalls
- Artifact recognition
Domain 8: Wound Care and Wound Healing
Postoperative management and healing-by-intention decisions after defect closure.
- Second-intention healing candidacy
- Dressing selection by wound type
Domain 9: Dermatopathology
Slide interpretation under time pressure, often the highest-yield and most heavily tested knowledge area.
- Distinguishing tumor from inflammatory mimics
- Margin assessment accuracy
Domain 10: Surgical Complications
Recognition and management of intraoperative and postoperative complications.
- Bleeding and flap compromise management
- Infection recognition and response
Domain 11: Instrumentation
Equipment familiarity across excision, processing, and closure.
- Frozen section equipment function
- Reconstructive instrument selection
For a longer treatment of how these eleven areas interconnect on exam day - for instance, how a single vignette can blend dermatopathology with surgical complications - see the complete domains guide.
Fees, Dates & Deadlines
Budget and timing mistakes are avoidable, and they're also expensive. Here is the fee structure exactly as published:
- Initial application: USD 1,800
- One-component retake: USD 900
- Both-component retake: USD 1,800
- Late application: USD 540 (in addition to the base fee)
For 2026, the exam is scheduled for September 24. The first application deadline is June 24, and the final application deadline - after which the late fee applies - is July 24. That gives a fairly tight window between locking in your application and sitting the exam, so practical case submission and documentation gathering should happen well before June. A full breakdown of every fee scenario, including how retake costs compound if both components need to be repeated, is available in the MMS Certification Cost 2026 guide, and the exact deadline mechanics are laid out in the MMS Exam Dates 2026 guide.
Key Takeaway
Apply by June 24 if possible. Missing that date doesn't disqualify you, but it does add USD 540 to your bill and compresses your final-stretch study window.
Passing Standard
The published passing standard is a scaled score of at least 500 on a 200-800 scale. This is a criterion-referenced standard rather than a fixed percentage of correct answers, which means the raw number of questions you need to get right isn't published as a flat percentage - the scaling accounts for item difficulty. Rather than fixating on a guessed raw-score target, focus preparation on comprehensive coverage of all eleven content areas so that no single weak domain drags the scaled result down. The scoring mechanics and what "500" actually represents in practice are unpacked further in the MMS Passing Score 2026 guide.
Certification Term & CME
Once earned, the subspecialty certification carries a ten-year term, subject to ongoing Osteopathic Continuous Certification (OCC) requirements rather than a single high-stakes retest at the end of the decade. Time-limited AOBD Diplomates need 60 CME credits during the 2025-2027 cycle, of which 20 must be specialty-specific Category 1-A credits tied to Mohs practice. Don't let this recertification math sneak up on you - Category 1-A credits accumulate more slowly than general CME, so front-load them if you're mid-cycle.
A Domain-Aligned Study Sequence
A generic study calendar is only useful if it's mapped onto the eleven content areas above rather than treated as an abstract productivity exercise. Here's a compressed sequence that front-loads the heaviest cognitive-load domains - dermatopathology and histological technique - while they're freshest, and saves lighter recall-based domains for the final review week.
Dermatopathology & Histological Technique
- Slide review sessions with timed self-quizzing
- Frozen section artifact recognition drills
Tumor Biology, Indications, and Surgical Anatomy
- Map anatomic danger zones by body region
- Cross-reference tumor subtype with indication rationale
Anesthesia, Preop Evaluation, Technique, Instrumentation
- Dosing limit recall under time pressure
- Instrument-to-task matching exercises
Wound Healing & Surgical Complications, then Full Mixed Review
- Timed 110-question mock blocks
- Weak-area re-drill using missed-question logs
Running full-length, timed practice blocks in the final week matters more than reviewing notes passively - the two-hour, 110-question format has its own pacing rhythm that's hard to internalize without simulating it. You can build that pacing familiarity using the practice question sets on MMS Exam Prep, which mirror the format and let you track domain-level performance rather than just an overall score. For a structured attempt-by-attempt plan rather than just a weekly outline, see the full MMS Study Guide.
Frequently Asked Questions
The initial written component has 110 multiple-choice questions administered in a two-hour testing window.
No. Missing practical cases prevents you from taking the written component - the six-case submission functions as a gate that must be cleared first.
A practical retake requires three new cases; you cannot resubmit the original six cases with revisions.
Yes. The clinical pathway (500 cases in the preceding three years, no fellowship required) remains open through December 31, 2028. After that date, an accredited fellowship becomes mandatory.
You need a scaled score of at least 500 on the published 200-800 scale, applied to the initial written component.
For related answers on terminology, certification structure, and career context, browse What Is MMS Certification?, MMS Certification, and MMS Jobs. And when you're ready to test your domain-by-domain readiness against realistic timed questions, head back to the main practice test platform.