CPT Code 99284: ED Billing, Documentation, and Reimbursement in 2026

What Is CPT Code 99284?

CPT code 99284 is a level 4 emergency department evaluation and management code defined by the American Medical Association for ED visits that require moderate-complexity medical decision making. As of the 2023 CPT revision, ED E/M codes 99281 through 99285 are selected based on MDM complexity or total time, and 99284 sits at the level where diagnostic workup, risk assessment, and treatment planning demand thorough documentation to support the billed complexity.

• 2026 reimbursement: The Medicare physician fee for CPT 99284 is approximately $118 under the 2026 CMS Physician Fee Schedule using the national conversion factor of $33.40. Facility fees add $500 to $2,500 depending on the hospital. Commercial payers typically reimburse at 110% to 150% of the Medicare rate.
• Documentation requirement: Payers require documentation that demonstrates moderate-complexity MDM, including the number of diagnoses or management options considered, the amount and complexity of data reviewed, and the risk of complications or morbidity.
• Most common denial cause: CMS audit data shows roughly one in five 99284 claims is downcoded or denied, almost always because the documentation fails to support moderate complexity, not because the clinical care was insufficient.

What CPT Code 99284 Represents

CPT code 99284 is one of five ED E/M codes (99281 through 99285) published by the AMA. It covers emergency department visits where the provider’s medical decision making reaches moderate complexity. Unlike office E/M codes, ED codes do not distinguish between new and established patients. The code applies equally to a first-time visitor and a patient with a long history at the facility.

Since the 2023 CPT revision, ED E/M level selection is based on either the complexity of medical decision making or the total time spent on the encounter. For 99284, the MDM path requires moderate complexity, and the time path covers encounters of 60 to 74 minutes. Most ED claims are coded on MDM because time-based coding requires the provider to document total time accurately, which is difficult in the pace of an emergency department.

Typical clinical scenarios that support 99284 include a moderate asthma exacerbation requiring multiple nebulizer treatments and monitoring, abdominal pain with imaging and serial exams to rule out appendicitis, a complicated laceration with risk of infection or foreign body, and chest pain requiring serial troponins and cardiac monitoring with a moderate differential. In each case, the provider evaluates multiple diagnoses, reviews moderate data, and manages moderate risk. That is the clinical reality 99284 captures.

How Does 99284 Compare to Other ED E/M Levels?

Understanding where 99284 sits relative to the other four ED codes is what prevents undercoding and overcoding. Here is how all five levels compare on the factors payers evaluate:

The jump from 99283 to 99284 is where most coding disputes happen. The difference comes down to whether the MDM crosses from low-moderate into moderate, and that distinction lives entirely in the documentation. Across the billing companies we vet at Billing Service Quotes, the providers who lose the most revenue on ED coding are the ones who routinely perform level 4 work but document at a level 3 standard.

For a deeper look at how payers process these claims after submission, see our guide on ERA in medical billing.

What Documentation Does 99284 Require?

Reimbursement for 99284 encounters hinges on proving that the provider’s medical decision making reached moderate complexity. Under the AMA’s MDM framework, moderate complexity requires meeting the threshold in at least two of three elements.

• Number and complexity of problems addressed. The encounter must involve one or more chronic illnesses with mild exacerbation, two or more undiagnosed new problems with uncertain prognosis, or an acute illness with systemic symptoms. A single straightforward problem does not reach this threshold.
• Amount and complexity of data reviewed and analyzed. The provider must document review and analysis of tests, records, or consultations at a moderate level. This includes ordering and reviewing labs, imaging, or prior records, plus independent interpretation of studies when applicable. Simply writing “labs reviewed” without summarizing findings and their impact on decision making does not meet the standard.
• Risk of complications, morbidity, or mortality. Moderate risk includes prescription drug management, decisions about minor surgery with identified risk factors, and diagnoses or treatments that could significantly affect the patient if not managed properly. The documentation must show the provider weighed these risks in their decision making, not just that they existed.

One question we hear constantly from practice managers is why their 99284 claims keep getting downcoded when the clinical care was clearly at that level. The answer is almost always the same: the provider did the work, but the note does not show the thought process payers need to see. A note that says “CT abdomen ordered” is a fact. A note that says “CT abdomen ordered to evaluate for appendicitis given migratory RLQ pain, guarding, and elevated WBC” is a medical decision. Payers pay for the decision, not the fact.

What Modifiers Apply to CPT 99284?

Modifier usage on ED E/M claims is one of the most frequent sources of denials, and 99284 is no exception. The modifiers that apply most often to this code are:

• Modifier 25: Significant, separately identifiable E/M service on the same day as a procedure. This is the most commonly appended modifier on ED E/M claims and the most frequently audited. CMS has proposed a 50% payment reduction on same-day E/M visits billed with procedures under the CY 2027 Physician Fee Schedule proposed rule, which would directly affect 99284 claims paired with modifier 25. For the full breakdown, see our coverage of the modifier 25 payment reduction.
• Modifier 27: Multiple outpatient hospital E/M encounters on the same date. Used when a patient is seen, discharged, and returns to the ED on the same day for a different problem.
• Modifier 76: Repeat procedure by the same physician on the same day. Applies when the same provider performs the same service again during a subsequent encounter.
• Modifier 59: Distinct procedural service. Used to indicate that a service is separate from another service performed on the same day. CCI edits may bundle certain procedures with 99284, and modifier 59 unbundles them when the services are truly distinct.

Across the billing companies we work with, the providers who bill modifier 25 with 99284 without documenting why the E/M was separately identifiable are the ones generating the most audit flags. The fix is straightforward: the note must clearly show that the E/M service involved decision making above and beyond the procedure itself.

Five Costly 99284 Billing Mistakes

Every ED billing team encounters the same set of preventable errors on 99284 claims. These are the five that cost the most revenue based on the patterns we see when matching providers with billing partners.

1. Undercoding to avoid audit scrutiny. Defaulting to 99283 when the documentation supports 99284 leaves $30 to $40 per claim unbilled. Over hundreds of encounters per month, that gap compounds into tens of thousands in lost annual revenue.
2. Documenting facts without decisions. A note that lists tests ordered and results received without explaining how those results changed the differential or treatment plan will not meet moderate-complexity MDM. Payers want the clinical reasoning, not just the data points.
3. Over-reliance on EHR templates. Cloned documentation that carries the same language across encounters regardless of the clinical situation is a red flag for auditors. Template notes that do not match the specific encounter are a leading cause of recoupments.
4. Missing or late physician signatures. Claims can be denied if the attending physician’s signature or authentication is not timely. Payers vary on their timely signature requirements, but most Medicare Administrative Contractors expect the note to be authenticated within 24 to 48 hours.
5. Ignoring POS alignment. CPT 99284 must be billed with the correct place of service code. When paired with POS 23 for hospital ED encounters, the documentation, acuity level, and setting must all align. A mismatch triggers automatic payer edits.

In-House vs. Outsourced ED Billing

Whether to handle 99284 coding and billing in-house or outsource it to a specialized partner depends on volume, denial rates, and how much revenue is leaking at this code level.

A single-provider ED or urgent care with a clean payer mix and low denial rates may manage 99284 coding well in-house, provided the coding staff stays current on MDM criteria and payer-specific documentation expectations. The challenge comes with scale. A multi-provider emergency department billing hundreds of 99284 encounters per month across a dozen payers, each with slightly different documentation thresholds and modifier rules, often finds that a specialized billing partner catches the revenue that an overstretched in-house team misses.

In our experience matching providers with billing partners, the practices that benefit most from outsourced ED coding are the ones that can see their denial rates on 99284 but cannot identify the root cause. A specialized partner does not just post the payments. They read the denial codes, spot the documentation patterns driving the downcodes, and feed that intelligence back to the clinical team so the same errors stop repeating. That feedback loop is where the real value lives, and it is the part most in-house billing operations do not have the bandwidth to sustain.

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