Critical Care Billing Explained: Avoiding Undercoding & Overcoding Risks
Critical care services are among the most complex encounters to code and bill. These services, typically billed under CPT code 99291 (first 30–74 minutes) and 99292 (each additional 30 minutes), involve high-stakes care for patients facing life-threatening conditions. Because of the documentation requirements and time-based nature of critical care coding, it’s easy for providers and practices to run into compliance risks—either through undercoding (losing revenue) or overcoding (risking audits and penalties).
This guide breaks down how critical care billing works, the most common pitfalls, and how to avoid them.
What Counts as Critical Care?
According to CMS and CPT guidelines, critical care is defined as direct delivery of medical care by a physician or qualified healthcare professional for a critically ill or critically injured patient. The key criteria are:
Life-threatening condition: The patient’s condition places them at risk of imminent deterioration or death.
Direct provider involvement: Continuous and active decision-making is required.
Time requirement: Time must be documented and must represent face-to-face critical care (not procedural or teaching time).
CPT Codes for Critical Care
99291: First 30–74 minutes of critical care
99292: Each additional 30 minutes
Example: If a provider spends 110 minutes in critical care, they would bill 99291 + 99292 x1.
Risks of Undercoding
Many providers unintentionally undercode critical care services because they:
Fail to document total time spent
Default to an inpatient E/M code (e.g., 99233) instead of critical care
Leave out key clinical elements like organ failure, life-threatening diagnoses, or interventions
Impact: Lost revenue for services legitimately rendered.
Risks of Overcoding
On the other hand, overcoding happens when:
Time is exaggerated or not clearly supported in documentation
Non-critical care activities (family discussions, procedures) are inappropriately counted as critical care time
The patient doesn’t truly meet critical illness criteria
Impact: Triggers payer audits, compliance investigations, and potential paybacks.
Documentation Essentials
To avoid both undercoding and overcoding, documentation must:
State the critical condition (e.g., acute respiratory failure, septic shock, cardiac arrest)
Describe interventions and decision-making
Clearly note time spent in increments (e.g., “Provider spent 65 minutes of critical care time in evaluation and management of septic shock.”)
Exclude separately billable services (e.g., procedures billed with their own CPT codes)
Best Practices for Compliance
Track time in real-time: Don’t reconstruct time later.
Use templates or smart phrases for consistent documentation.
Educate providers on what counts toward critical care time.
Audit regularly to identify trends in undercoding or overcoding.
Final Thought
Critical care billing is a delicate balance. Undercoding leaves money on the table, while overcoding can invite unwanted scrutiny. By documenting thoroughly and coding accurately, providers not only protect their revenue but also ensure compliance. The key is simple: clear documentation, accurate coding, and ongoing education.