Medicare needs 104 minutes before 99292; CPT needs 75. What counts toward ED critical care time, what is bundled, and the nine errors auditors look for first.
Critical care is the one emergency department service where time, not medical decision making, sets the code. That makes critical care coding 99291 and 99292 simpler to describe and easier to get wrong: a missing time statement, a procedure counted twice or the wrong payer threshold can turn a correct clinical picture into an unsupported claim. Our ED coding automation guide places critical care inside the wider ED workflow.
The ED visit codes 99281 to 99285 are leveled on MDM alone, as our guide to ED E/M leveling explains. This page covers what changes when the patient crosses into critical care: the definition, the time rules Medicare and CPT disagree on, what counts toward the clock, what is bundled, and the documentation that holds up in an audit.
What qualifies as critical care
Medicare defines critical care as direct delivery of care to a critically ill or injured patient, where one or more vital organ systems are acutely impaired and there is a high probability of imminent or life-threatening deterioration (CMS, MLN006764, May 2026). The definition is about the patient's condition and the physician's work, not the location. A patient in an ED resuscitation bay can meet it; a patient in an ICU bed who is stable and improving may not.
Two practical consequences for the ED:
- Disposition doesn't decide it. There is no CPT requirement that the patient be admitted. A patient with anaphylaxis or an opioid overdose who needs intensive intervention and later goes home can still qualify (ACEP, Critical Care FAQ).
- Severity alone doesn't decide it either. The physician has to be delivering the high-complexity work the definition describes. A sick patient who is being watched, not actively managed, doesn't generate critical care time.
Medical necessity is where audits bite first. In a 2020 audit of one academic physician practice, the HHS Office of Inspector General (OIG) found that 14 of 150 sampled critical care services did not meet the medical necessity requirements, because the patients were stable rather than at risk of imminent deterioration (OIG, A-03-18-00003). That sample was hospital-based rather than ED-specific, but the failure mode carries over directly.
Critical care coding 99291 and 99292: the time rules
99291 covers the first 30 to 74 minutes of critical care on a date of service, and it is reported once per date even when the time is not continuous. Under 30 minutes, the service is reported as an E/M visit instead, which in the ED means 99281 to 99285.
The disagreement is over 99292. CPT allows the first unit once total time reaches 75 minutes. Since January 1, 2023, Medicare requires the full additional 30 minutes, so 99292 is not reportable until total time reaches 104 minutes (CMS, MLN006764; ACEP, Critical Care FAQ).
| Total critical care time | CPT reporting | Medicare reporting |
|---|---|---|
| Under 30 minutes | ED E/M (99281 to 99285) | ED E/M (99281 to 99285) |
| 30 to 74 minutes | 99291 × 1 | 99291 × 1 |
| 75 to 103 minutes | 99291 + 99292 × 1 | 99291 × 1 |
| 104 to 133 minutes | 99291 + 99292 × 1 | 99291 + 99292 × 1 |
| 134 to 163 minutes | 99291 + 99292 × 2 | 99291 + 99292 × 2 |
The 75-to-103-minute band is the one that matters operationally. A charge rule that applies CPT thresholds to every payer overbills Medicare in that band; a rule that applies Medicare thresholds everywhere underbills payers that follow CPT. Check each commercial and Medicare Advantage contract rather than assuming. Some follow CMS, some follow CPT.
What counts toward critical care time
Time counts when the physician is immediately available to the patient and devoting full attention to their care. That includes bedside evaluation and treatment, reviewing test results and imaging, discussing the case with other clinicians, documenting, and discussions with family or surrogates when the patient cannot participate and the discussion is needed to make treatment decisions (ACEP, Critical Care FAQ).
Time does not count when it is spent on separately reportable procedures. The NCCI policy manual is explicit that practitioners shall not include the time devoted to separately reportable services when calculating critical care time (CMS, NCCI Policy Manual 2026, Chapter XI, section I.2). In the ED that usually means cardiopulmonary resuscitation (92950), endotracheal intubation (31500), central venous catheter placement (36555 or 36556), intraosseous access (36680) and tube thoracostomy (32551). The clock pauses for each one and restarts afterward.
Bundled services the physician cannot bill separately
The reverse also applies. Some services are included in 99291 and 99292 for practitioners and cannot be billed on top of them. Medicare's list covers interpretation of cardiac output measurements, chest X-rays, pulse oximetry, blood gases, gastric intubation, collection and interpretation of physiologic data such as ECGs and blood pressures, temporary transcutaneous pacing, ventilator management and vascular access procedures (CMS, MLN006764).
The rule works in both directions, and coders need both halves:
| Service | Bill separately? | Counts toward critical care time? |
|---|---|---|
| Endotracheal intubation (31500) | Yes | No |
| Central line (36555, 36556) | Yes | No |
| CPR (92950) | Yes | No |
| Ventilator management | No, bundled | Yes |
| Chest X-ray interpretation | No, bundled | Yes |
| ECG interpretation | No, bundled | Yes |
| Peripheral vascular access | No, bundled | Yes |
Double-dipping, where procedure time is counted toward critical care and the procedure is billed as well, is a common time error and an easy one for auditors to spot. The table makes it easy to test a chart: every row either appears on the claim or in the minutes, never both.
Critical care and an ED visit on the same day
Patients often arrive stable and deteriorate. When that happens, Medicare allows the same practitioner to report both an ED E/M and critical care on the same date, with modifier 25 on the E/M, if the E/M was medically necessary, was provided before critical care began and does not duplicate it (CMS, MLN006764). The order is the test. An ED visit documented after critical care, or one that restates the same work, is not separately payable.
CPT permits both services on the same date for non-Medicare patients. As with the time thresholds, the payer's policy decides which rule applies to a given claim.
Split or shared critical care
When an emergency physician and an advanced practice provider in the same group both deliver critical care, Medicare treats it as a split or shared service. Unlike ED visits, where a substantive part of the MDM can decide the billing practitioner, split or shared critical care is decided on time alone: whoever furnished more than half the combined time bills, and the claim carries modifier FS on 99291 and any 99292 units. The combined total, without counting overlapping minutes twice, sets the number of units (CMS, MLN006764).
Two related rules catch groups out. Only one 99291 is reported per patient per date across a group in the same specialty; a second physician from the same group who takes over reports 99292 for their time. Physicians from different specialties, such as an emergency physician and a surgeon, can each report their own critical care when the services are not duplicative. And when critical care is unrelated to a procedure with a global surgical period, Medicare expects modifier FT.
Worked example: one time log, two payers
Illustrative scenario for education. Not a MEDIQCODE result and not a coding determination for any real encounter.
An adult arrives hypotensive and hypoxic with suspected pneumonia. The emergency physician documents this time log:
| Activity | Minutes | Counts toward critical care? |
|---|---|---|
| Initial evaluation, resuscitation orders, fluids and pressor start | 20 | Yes |
| Endotracheal intubation (31500) | 10 | No, separately billed |
| Ventilator setup and management, pressor titration, reassessment | 25 | Yes |
| Central line placement (36556) | 15 | No, separately billed |
| Review of labs, chest X-ray, ECG; call with ICU team | 15 | Yes |
| Goals-of-care discussion with family (patient intubated) | 20 | Yes |
| Documentation at the ED workstation | 10 | Yes |
| Total countable | 90 |
Medicare claim: 99291 × 1, plus 31500 and 36556. At 90 countable minutes the Medicare threshold for 99292 (104 minutes) is not met. Chest X-ray and ECG interpretation, and ventilator management, are not billed separately.
Payer following CPT: 99291 + 99292 × 1, plus the same two procedures. Ninety minutes falls in the CPT 75-to-104 band.
The error this example is built to catch: if the 25 procedure minutes had been added to the total, the log would show 115 minutes and the Medicare claim would carry a 99292 the documentation doesn't support. The physician's attestation should state total critical care time and that it excludes separately billed procedures. Diagnosis coding follows the ICD-10-CM outpatient guidelines; for example, sepsis with septic shock and acute hypoxic respiratory failure would draw on codes such as A41.9, R65.21 and J96.01, sequenced by the coder under the official guidelines.
Whether the procedures need a modifier alongside 99291 depends on payer edits. Check the NCCI procedure-to-procedure tables and the payer's own policy for each pair.
The facility claim is a separate calculation
The hospital bills its own critical care on the facility claim, and its time is built from different records. A hospital reporting 99291 needs at least 30 minutes of critical care, and when a trauma team is activated in connection with critical care it may add G0390 (CMS, OPPS Q&A). The practitioner bundling list doesn't apply the same way either: NCCI states that facilities may separately report services that are bundled into critical care for practitioners (CMS, NCCI Policy Manual 2026, Chapter XI, section U).
Facility and professional critical care time rarely match, and they aren't meant to. The two claims are compared in full in facility vs professional ED coding. Critical care is also excluded from some payers' ED level programs, covered in how payer ED downcoding works.
Nine errors auditors find first
- No total time. "Critical care provided" without minutes cannot support 99291.
- Time that includes procedures. The attestation should say the time excludes separately billed procedures.
- A patient who doesn't meet the definition. Stable, improving or merely monitored patients fail the test even with a long time total.
- CPT thresholds on a Medicare claim. 99292 between 75 and 103 minutes is a Medicare overpayment.
- Bundled services billed on top. Chest X-ray reads, ECG interpretation, pulse oximetry and ventilator management belong inside 99291.
- Two 99291s from one group. Same specialty, same group, same date: one 99291, then 99292.
- An ED visit that follows or duplicates critical care. Medicare pays the ED E/M with critical care only when it came first and stands apart.
- Split or shared critical care leveled on MDM. Critical care splits on time only, and needs modifier FS.
- Under 30 minutes billed as 99291. Below the floor, it's an ED E/M.
Most of these are documentation defects, not coding defects. The fix sits with provider education and templates, and the coder's job is to catch them before the claim drops. A regular sample, drawn and scored with a defensible measurement method, tells you whether that is happening.
Where AI-assisted coding helps, and where it doesn't
Critical care is a good fit for software in one narrow sense: much of the check is arithmetic. Extracting time entries, subtracting procedure minutes, applying the right payer threshold and flagging bundled services billed on top are mechanical, and a system that does them consistently removes the time errors listed above. Published evidence on how accurate AI coding is today is worth reading with that distinction in mind.
The medical necessity judgment is different. Whether a patient met the critical illness definition is a clinical question that turns on the whole record, and it is the question OIG reviewers ask first. Any AI-assisted workflow for critical care coding 99291 should route that call to a credentialed coder, which is why we'd keep critical care charts in coder-in-the-loop review rather than any direct-to-bill tier. MEDIQCODE's approach is built on that principle: coders sign off the codes. The same accountability argument runs through whether AI will replace medical coders.
Before trusting any tool with critical care, ask it to show three things on your own de-identified charts: which minutes it counted and excluded, which payer threshold it applied and why, and what it surfaces to the coder when the time total is missing or the procedure time isn't separated. If it quotes a share of critical care charts released without review, ask for a denominator you can audit.
Frequently asked questions
When can I report 99292 for a Medicare patient?
Only once total critical care time on that date reaches 104 minutes. Medicare requires a full additional 30 minutes beyond the 74 minutes covered by 99291. CPT allows the first 99292 from 75 minutes, so payers that follow CPT pay earlier.
Does time spent intubating or placing a central line count toward critical care?
No. Time spent on separately reportable procedures such as 31500, 36555, 36556 or 92950 is excluded from critical care time. The procedure is billed separately and the critical care clock pauses while it is performed.
Can the ED physician bill an ED visit and critical care on the same day?
For Medicare, yes, if the ED visit was medically necessary, came before critical care began and does not duplicate it. Modifier 25 goes on the ED E/M code.
Does the patient have to be admitted for critical care to be billable?
No. There is no disposition requirement. A patient who needed critical care and was later discharged from the ED can still support 99291 if the definition and time were met and documented.
How is split or shared critical care billed?
On time only. The practitioner who furnished more than half of the combined critical care time bills, with modifier FS on 99291 and any 99292 units.
This article is educational and does not constitute a coding determination for any specific patient encounter. Payer policies on critical care thresholds vary; confirm the rule each payer applies.
