Evaluation and Management (E/M) Coding

What Is Evaluation and Management Coding?

Evaluation and Management (E/M) codes are a section of the Current Procedural Terminology (CPT) code set published by the American Medical Association (AMA). They describe the cognitive work a provider does when seeing a patient — taking a history, examining the patient, and making clinical decisions. E/M codes are among the most frequently billed codes in outpatient medicine, so accurate selection matters enormously for correct reimbursement and for compliance with payer rules.

For office and outpatient visits, E/M codes fall in the 99202–99215 range. The code chosen reflects the complexity of the encounter, not simply how long the visit lasted.

New Patient vs. Established Patient

Before selecting a code, you must determine the patient's status.

• New patient: A patient who has not received any professional service from the physician, or from another physician of the same specialty and subspecialty who belongs to the same group practice, within the past three years.
• Established patient: A patient who has received a professional service from the physician, or from another physician of the same specialty and subspecialty in the same group practice, within the past three years.

This distinction matters because new-patient codes (99202–99205) and established-patient codes (99211–99215) are separate code sets with different descriptors. If there is any question about patient status, current AMA guidance instructs you to code as a new patient when the record does not clearly show a prior relationship.

The Two Pathways to Code Selection

Current AMA E/M guidelines (revised effective 2021 and updated in subsequent CPT cycles) allow providers to select the office/outpatient E/M level using either:

1. Medical Decision Making (MDM) — the preferred and most commonly audited method.

2. Total time — the total time the provider spends on the date of service, including time spent before and after the face-to-face encounter on activities directly related to the visit.

As a medical assistant, you will most often support the MDM pathway by ensuring documentation is complete and accurate. You will not make clinical decisions, but you must understand MDM so you can help providers capture the right information and so you can perform coding tasks within your scope.

Understanding Medical Decision Making

MDM has three elements. The final MDM level is determined by meeting or exceeding requirements in at least two of the three elements.

Element 1 — Number and Complexity of Problems Addressed

This reflects how many problems the provider is addressing and how serious or uncertain they are. Categories range from minimal (one self-limited problem) up to high (one or more chronic illnesses with severe exacerbation, or a problem that poses a threat to life).

Element 2 — Amount and/or Complexity of Data Reviewed and Analyzed

This captures work the provider does to gather information: reviewing external records, ordering tests, independently interpreting results, or discussing the case with another provider. Categories range from minimal or none up to extensive.

Element 3 — Risk of Complications and/or Morbidity or Mortality

This reflects the risk associated with the presenting problem(s), the diagnostic procedures ordered, and the management options selected. Categories range from minimal up to high.

MDM Levels and Corresponding Codes

| MDM Level | New Patient Code | Established Patient Code |

|---|---|---|

| Straightforward | 99202 | 99212 |

| Low | 99203 | 99213 |

| Moderate | 99204 | 99214 |

| High | 99205 | 99215 |

Note: 99211 may be reported for established patients who do not require a physician's presence and involves minimal MDM.

Always use the official AMA MDM complexity table from the current CPT codebook when scoring a note. The table is the authoritative reference; your personal judgment about complexity should not override the table definitions.

Time-Based Coding

When a provider chooses to code by time, total time on the date of the encounter is used (not just face-to-face time, under current guidelines). The CPT codebook lists specific time thresholds for each code level. Time-based coding is particularly useful for encounters that involve extensive counseling or coordination of care.

Documentation Requirements and Patient Safety

Accurate E/M coding depends entirely on accurate documentation. As a medical assistant, you have a professional and ethical obligation to:

• Never alter, embellish, or create documentation to support a higher-level code. This is fraud.
• Flag missing information to the supervising provider before the claim is submitted, using your facility's standard process.
• Protect patient privacy when handling office-visit notes, including during peer audit exercises; follow HIPAA rules at all times.
• Understand scope of practice: Medical assistants assist with coding tasks under provider supervision. Final responsibility for the accuracy of a submitted claim rests with the billing provider and the practice.

Up-coding (billing a higher level than documented) and down-coding (billing lower than documented, which can also constitute fraud against patients or payers) are both compliance risks. When in doubt, query the provider — never guess.

Putting It Together: A Step-by-Step Approach

1. Read the entire office-visit note before touching the codebook.

2. Determine new vs. established patient status.

3. Identify which code set applies (99202–99205 or 99211–99215).

4. Score each of the three MDM elements using the official MDM table.

5. Find the two elements that are met or exceeded and assign the MDM level.

6. Select the E/M code that matches the MDM level and patient status.

7. Write a brief rationale documenting your reasoning — this mirrors what an auditor will do.

8. Double-check: does the documentation actually support each element you scored? If not, query the provider.