Quick answer: Medical decision making (MDM) is one of two ways to select an office or outpatient E/M level; the other is total time. Coders score MDM on three elements: the number and complexity of problems addressed, the amount and complexity of data reviewed and analyzed, and the risk of complications from patient management. You assign a level when two of the three elements meet or exceed it: straightforward (99202, 99212), low (99203, 99213), moderate (99204, 99214), or high (99205, 99215).
What Is Medical Decision Making (MDM) in E/M Coding?
It plays a significant role when you determine the appropriate level of service to report for a patient encounter. As of the 2021 updates (and continuing today), the American Medical Association (AMA) and Centers for Medicare & Medicaid Services (CMS) simplified the E/M coding guidelines for office and outpatient services. As a result, these guidelines now focus more on Medical coding MDM or time.
Here’s a detailed guide to Medical Decision Making (MDM) for coding and billing:
What Are the Three Elements of MDM?
Specifically, three elements determine MDM:
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Number and Complexity of Problems Addressed
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Amount and/or Complexity of Data to be Reviewed and Analyzed
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Risk of Complications and/or Morbidity or Mortality of Patient Management
In short, you must meet or exceed two out of three elements to support a particular MDM level.
What Are the Four Levels of MDM?
There are four levels of MDM:
| MDM Level | Problems Addressed | Data Reviewed | Risk |
|---|---|---|---|
| Straightforward | 1 self-limited or minor problem | Minimal or none | Minimal risk of complications or morbidity |
| Low | 2+ self-limited/minor problems, or 1 stable chronic illness | Limited (e.g., 2 unique tests or documents, or an independent historian) | Low risk (e.g., OTC meds, minor procedures) |
| Moderate | 1+ chronic illness with exacerbation or 2+ stable chronic illnesses | Moderate (e.g., 3 tests or documents, an independent interpretation, or a discussion with an external physician) | Moderate (e.g., prescription drugs, minor surgery with risk) |
| High | 1+ chronic illnesses with severe exacerbation or acute illness posing threat to life/function | Extensive (e.g., at least two of the three data categories) | High (e.g., drug therapy requiring intensive monitoring for toxicity, decision to hospitalize) |
Element Details
Problems Addressed
A problem is “addressed” when it is actively evaluated, treated, or managed at the encounter.
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Stable chronic illness is considered less complex than an exacerbated chronic illness or an acute problem with systemic symptoms.
Data Reviewed and Analyzed
Three types:
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Category 1: Tests, documents, or independent historian (review of external notes, review of each unique test result, ordering of each unique test, or an assessment that requires an independent historian)
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Category 2: Independent interpretation of a test performed by another physician or QHP (not separately reported)
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Category 3: Discussion of management or test interpretation with an external physician, other QHP, or appropriate source (not separately reported)
- In addition, ordering a test includes its later review, so count each unique test only once.
Risk of Complications and/or Morbidity/Mortality
Specifically, risk includes:
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Management decisions made (e.g., prescription, procedures)
- Management options considered, including options the patient declines
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Nature of diagnostic/therapeutic interventions (e.g., elective surgery with identified risk factors)
How Do You Code MDM Accurately?
Document Clearly
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Above all, avoid ambiguous language. Be specific: “acute exacerbation” is stronger than “symptoms today.”
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Note decision-making rationale even if no new tests or treatment is ordered.
Support Risk Appropriately
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If prescribing meds, justify risk level (e.g., “start on anticoagulant due to atrial fibrillation”).
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If recommending follow-up only, explain why that’s medically appropriate.
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Avoid Overcoding or Undercoding
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Don’t automatically assign higher MDM due to comorbidities unless they are addressed during the encounter.
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However, a thorough history and exam do not affect MDM level under 2021+ guidelines. Instead, MDM or time determines the code.
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Use AMA MDM Grid
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Use the official AMA grid for documentation as well as audit support.
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This grid is available in the current CPT Professional Edition as well as on the AMA website.
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What Do Auditors Look for in MDM Documentation?
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Time-based Coding (if used instead of MDM): Total time spent by provider on the date of service (face-to-face + non-face-to-face).
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EHR Templates: Customize templates so they prompt detailed documentation of MDM elements.
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Audit Trail: Keep documentation that reflects your decision-making, particularly for high-risk situations.
Resources for Further Reading
Coding Clarified E M 2025
AMA CPT E/M Guidelines (2025) AMA 2023 E/M descriptors and guidelines
CMS E/M Services Guide CMS E/M services guide
Interactive tools for E/M services
