- ED E/M levels are driven by MDM under the 2023 rules, not by history and exam bullets.
- Critical care time is coded separately and has its own threshold.
- Data and risk in the ED count differently than in clinic; score them on their own terms.
Different rules, reset in 2023
In 2023 the MDM-based revision that reached office codes in 2021 (covered in the guide on the 2021 E/M changes) arrived in the emergency department. History and exam no longer set the level; medical decision making does, alone, with ED-specific quirks.
The ED Codes: MDM Only, No Time Option
The surprise for office-trained coders: ED E/M codes (99281-99285) cannot be selected by time. The AMA's reasoning: emergency care is interrupted and non-linear, so total time is not a meaningful measure. Every level comes from the MDM table, using the same three columns described in the guide on medical decision making: problems addressed, data reviewed, and risk.
| Code | MDM Level | wRVUs | Typical clinical picture |
|---|---|---|---|
| 99281 | May not require physician presence | 0.25 | Suture removal, simple dressing change by staff |
| 99282 | Straightforward | 0.93 | Isolated minor complaint, no workup |
| 99283 | Low | 1.60 | Limited workup, low-risk presentation |
| 99284 | Moderate | 2.74 | Workup with labs/imaging, differential includes serious causes, Rx management |
| 99285 | High | 4.00 | Threat to life or function in the differential, extensive workup, high-risk decisions |
The 99284 vs. 99285 Line: Where the Level, and the Ambiguity, Live
Most ED coding variation sits at the moderate-to-high MDM boundary. The underused concept: the level reflects the condition you ruled out, not only the diagnosis you landed on. A chest pain patient discharged with reflux still had a differential that included acute coronary syndrome. The problem addressed was "chest pain, possible ACS", an undiagnosed problem with potential threat to life, not "GERD."
ED-specific risk anchors that support high complexity: a decision regarding hospitalization, parenteral controlled substances, drug therapy requiring intensive monitoring, and decisions about emergency surgery. A patient you seriously considered admitting, even if discharged with close follow-up, involved a hospitalization decision. Say so: "Considered admission; discharged with next-day cardiology follow-up after shared decision-making" captures a high-risk decision in one sentence.
Critical Care: 99291 and 99292
Critical care codes step outside the ED level system entirely and are time-based:
| Code | Service | wRVUs | Time |
|---|---|---|---|
| 99291 | Critical care, first hour | 4.50 | 30-74 minutes |
| 99292 | Critical care, each additional 30 min | 2.25 | 75+ minutes (each unit) |
Critical care requires two things at once: a critically ill or injured patient (high probability of imminent, life-threatening deterioration) and your direct personal management of that threat. The 30-minute minimum is cumulative across the encounter, need not be continuous, excludes separately codable procedures, and must be documented: "Total critical care time, exclusive of separately coded procedures: 45 minutes." Time spent reviewing data, talking with consultants, and discussing care with family when the patient cannot participate all counts.
When a patient deteriorates after the initial evaluation, critical care can be coded alongside the ED E/M on the same day, though payer rules vary. Record the ED-level work, then a distinct critical care note with its own timestamp and its own minutes (for example, "Critical care time: 40 minutes, exclusive of separately codable procedures"), so the claim shows two distinct services.
Procedures in the ED
Laceration repairs, reductions, splint applications, I&Ds, and similar procedures are separately codable alongside the ED E/M with Modifier 25 on the E/M, per the Modifier 25 guide. In the ED this is usually clean: the workup of the fall that produced the laceration is separate from the repair. The common failure is not unsupported Modifier 25 use; it is forgetting to code the procedure at all in a busy shift.
Where the ED Level Turns
Take chest pain. A focused evaluation with moderate-risk decision making, ruling out acute coronary syndrome with serial ECGs and troponins and discharging home, supports a 99284. High-risk decision making, an unstable patient, or a decision about thrombolytics or admission to a monitored bed supports a 99285 for the same complaint. The dividing line is the risk and complexity of the decisions, not the chief complaint, which is why two chest-pain patients can correctly carry different levels.