CPT® Code 99291

Quick Reference: CPT 99291

• Definition: Critical care, evaluation and management of the critically ill or critically injured patient; first 30–74 minutes.
• Basis for Billing: Time only — this is a purely time-based code. Medical Decision Making (MDM) is not used to select level.
• Time Threshold: Report once when a minimum of 30 minutes of critical care has been provided on a given calendar date. The code covers up to 74 minutes.
• Add-On Code: Pair with CPT 99292 for each additional 30-minute block beyond 74 minutes.
• Medicare Rule: Under CMS, 99292 cannot be added until 104 total minutes (74 + 30) have been reached — not at 75 minutes as CPT allows.
• Frequency: Report only once per calendar date per patient by the same physician or same-specialty group. Different specialties may each bill 99291 for distinct, non-duplicative services.
• Location Independent: Billing is driven by patient acuity and time — not by the physical location (ICU, ED, floor, or even office/transport).
• Minimum Time Exclusion: Critical care of fewer than 30 total minutes on a given date is not reported with 99291. Use a standard E/M code instead (e.g., 99231–99233).

CPT 99291 is the foundational code for adult and pediatric critical care services (patients older than 24 months). It is one of the most high-value and frequently audited codes in all of medicine — and one of the most misunderstood.

Unlike the standard E/M codes that were overhauled in 2021–2023 to allow MDM- or time-based selection, critical care remains strictly time-based. Documentation, bundling rules, and the critical CPT-vs.-Medicare time discrepancy continue to create compliance risk for intensivists, hospitalists, emergency physicians, pulmonologists, and any specialist managing a critically ill patient. This guide consolidates the 2026 AMA CPT guidelines and CMS final rules into one actionable reference.

1. Definition of Critical Care: The 3 Required Elements

Per the AMA CPT codebook and CMS policy, critical care is the direct delivery by a physician or other Qualified Health Professional (QHP) of medical care for a critically ill or critically injured patient. Three distinct criteria must all be met before 99291 can be legitimately billed. Simply being present in an ICU, managing a ventilator, or responding to a rapid response call is not sufficient on its own.

Element 1: Critical Illness or Injury

The patient must have a condition that acutely impairs one or more vital organ systems such that there is a high probability of imminent or life-threatening deterioration of the patient’s condition. Vital organ systems include, but are not limited to, the central nervous system, the circulatory system, the respiratory system, the hepatic system, the renal system, the metabolic system, and the hematologic system.

Examples of qualifying conditions include septic shock, acute respiratory failure requiring mechanical ventilation, hypertensive emergency with end-organ damage, massive pulmonary embolism with hemodynamic instability, status epilepticus, acute hepatic failure, diabetic ketoacidosis with altered consciousness, and multi-organ dysfunction syndrome.

What does NOT qualify: A patient who is stable in the ICU and responding favorably to established treatment does not meet this threshold. For example, a post-operative patient in the SICU whose vitals are stable, labs are trending toward normal, and who requires only routine monitoring would more appropriately be billed with a subsequent hospital care code (99231–99233).

Element 2: High-Complexity Decision Making and Intervention

The provider must be engaged in high complexity decision making to assess, manipulate, and support vital organ system function — either to treat single or multiple organ failure, or to prevent further life-threatening deterioration.

The provider’s full attention must be dedicated to the patient during the time being counted. This means that the physician or QHP cannot simultaneously provide services to another patient during the period of critical care time being billed.

Element 3: Time — Minimum 30 Minutes

A minimum of 30 minutes of critical care must be provided on the calendar date in question. Time is cumulative — it does not need to be continuous. A physician who sees a patient for 20 minutes in the morning and returns for 15 minutes in the afternoon has accrued 35 minutes of critical care and may bill 99291 for that date. The time must be documented specifically by the provider.

Critical distinction: Documentation of the patient’s condition (meeting the definition of critical illness) is the physician’s responsibility. The note must affirmatively support both the severity of the illness and the complexity of the interventions being provided — not merely state a location (e.g., “ICU care provided”).

2. Time Calculation Rules: CPT vs. Medicare (The 104-Minute Rule)

This is the single most important compliance distinction in critical care billing and the source of the most common audit failures. CPT guidelines and Medicare (CMS) rules differ significantly on when CPT 99292 (the add-on code) may be appended.

CPT (AMA) Time Rules

Under standard CPT guidelines, the time ranges are as follows: 99291 covers the first 30–74 minutes of critical care. When total critical care time reaches 75 minutes or more, one unit of 99292 (each additional 30 minutes) is added. CPT uses a midpoint convention, meaning 99292 is reportable once the midpoint of the additional 30-minute block has been passed (i.e., at 75 minutes).

Medicare (CMS) Time Rules — The 104-Minute Rule

For Medicare patients, a technical correction issued by CMS in the 2023 Physician Fee Schedule Final Rule changed the threshold. Medicare requires that the full 30 additional minutes must be provided before 99292 can be billed. This means: report 99291 alone from 30 to 103 minutes. Only after reaching 104 total minutes (74 + 30) may the provider add one unit of 99292. Each additional 99292 thereafter requires a full additional 30 minutes of critical care (134, 164 minutes, etc.).

Practical impact: A Medicare patient who received 90 minutes of critical care would be billed as 99291 only — not 99291 + 99292 — despite the fact that CPT rules would allow the add-on at 75 minutes.

Time Reporting Chart

flowchart TD
    A["Total Critical Care Time on Calendar Date"] --> B{">= 30 minutes?"}
    B -->|No| C["Bill standard E/M code (99231-99233)"]
    B -->|Yes| D{"Payer type?"}
    D -->|"Commercial / CPT rules"| E{">= 75 minutes?"}
    D -->|"Medicare / CMS rules"| F{">= 104 minutes?"}
    E -->|No| G["Bill 99291 x 1"]
    E -->|Yes| H["Bill 99291 + 99292 x N"]
    F -->|No| I["Bill 99291 x 1 only"]
    F -->|Yes| J["Bill 99291 + 99292 x N"]

What Counts as Critical Care Time

Time spent performing the following activities counts toward the critical care total: bedside evaluation and management; reviewing test results, imaging, and medical records; discussing the case with other providers involved in the patient’s care (consultants, nursing staff, pharmacists); documenting the critical care note; and spending time at the bedside or on the unit managing the patient — even if the patient is temporarily in a procedure suite or being transported.

What Does NOT Count as Critical Care Time

Time spent performing separately billable procedures (procedures not bundled into critical care) is excluded from the critical care time total. For example, if a physician spends 10 minutes performing an endotracheal intubation (CPT 31500), those 10 minutes cannot be added to the critical care total. Time spent by nurses or other clinical staff does not count. Time spent by a resident in the absence of the teaching physician does not count. Family discussions and updating the healthcare proxy, while valuable, are considered pre- and post-service work and generally do not count toward the critical care time units being billed.

3. Bundled vs. Separately Billable Services

A critical concept in 99291 billing is understanding which procedures are automatically included (bundled) into the critical care codes and which may be billed separately. Billing for a bundled service in addition to 99291 is a top RAC (Recovery Audit Contractor) audit target and constitutes improper billing.

Services Bundled Into 99291 / 99292 (Do NOT Bill Separately)

• Interpretation of cardiac output measurements (CPT 93561, 93562)
• Chest X-ray interpretation (CPT 71045, 71046; formerly 71010, 71015, 71020)
• Pulse oximetry (CPT 94760, 94761, 94762)
• Collection and interpretation of physiologic data stored in computers (e.g., ECGs, blood pressures, hematologic data — formerly CPT 99090, deleted in 2019)
• Gastric intubation (CPT 43752, 43753)
• Temporary transcutaneous pacing (CPT 92953)
• Ventilator management (CPT 94002, 94003, 94004, 94660, 94662)
• Vascular access procedures (CPT 36000, 36410, 36415, 36591, 36600)

Note for facilities: Hospital outpatient departments and inpatient facilities may still separately report some of these bundled services. The bundling restriction applies to the physician/QHP billing component, not the facility fee.

Procedures That ARE Separately Billable (Bill in Addition to 99291)

• Endotracheal intubation (CPT 31500) — time spent on procedure excluded from CC time
• Central venous catheter insertion (CPT 36555, 36556, 36557, 36558) — time excluded from CC time
• Cardiopulmonary resuscitation (CPT 92950) — time excluded from CC time
• Insertion of flow-directed catheter / Swan-Ganz (CPT 93503) — time excluded from CC time
• Lumbar puncture (CPT 62270) — time excluded from CC time
• Bladder catheterization (CPT 51701, 51702)
• Transfusion of blood components (CPT 36430, 36440) — billable by physician when separately documented
• Arterial line insertion (CPT 36620)
• Thoracentesis (CPT 32554, 32555)
• Paracentesis (CPT 49082, 49083)

Critical compliance reminder: When billing a separately payable procedure on the same date as 99291, the time spent performing that procedure must be subtracted from the critical care time total. If enough time is removed that the critical care time falls below 30 minutes, the 99291 cannot be billed at all on that date.

4. Audit-Proof Documentation Standards

Critical care notes are among the highest-value and most-audited claims in medicine. Because the code is purely time-based, vague or template-driven documentation creates significant compliance exposure. Auditors from RAC, OIG, and MACs consistently cite the following as deficiencies:

• No documented time. The most basic and most common deficiency. The note must contain a clear statement of the total time spent providing critical care, and ideally the start and stop time (or start time and duration). Example of compliant documentation: “Total critical care time: 55 minutes (0815–0910), not including time spent on separately billable procedures.” A vague statement such as “approximately an hour” is insufficient.
• Failure to document critical illness criteria. The note must articulate why the patient meets the definition of critical illness. Stating “patient in ICU” is not enough. Instead, document the specific organ system impairment and the imminent risk: “Patient with septic shock and early acute renal failure; vasopressor support (norepinephrine 0.12 mcg/kg/min) being titrated; high risk of cardiovascular collapse without immediate intervention.”
• Failure to document high-complexity decision making. The note must reflect the intensity of intervention. Documenting “continue current management” without specifying the management decisions being made does not support a critical care claim. Instead: “Titrating vasopressors based on MAP response, interpreting ABG for ventilator adjustments, reviewing lactate trend, coordinating with nephrology for possible CRRT initiation.”
• Template-generated notes that don’t reflect actual patient status. Copy-forward or auto-populated notes that are identical across multiple days are a major red flag in audits. Each day’s note must independently reflect the patient’s current condition and the day’s clinical decisions.
• Missing documentation of non-continuous time aggregation. If time is non-continuous, the note should document each episode. Example: “Critical care provided in two separate episodes: 0830–0900 (30 min) and 1415–1440 (25 min). Total critical care time: 55 minutes.”

Model Documentation Language

A high-quality critical care note will contain elements similar to the following: “I provided critical care services to this patient today. The patient continues to have septic shock with multi-organ dysfunction syndrome (cardiovascular and renal involvement), meeting criteria for critical illness with high probability of imminent deterioration. I spent this time performing a comprehensive bedside assessment, interpreting this morning’s labs (rising lactate, worsening creatinine), reviewing serial chest X-rays (increased bilateral infiltrates), titrating norepinephrine and vasopressin drips, adjusting ventilator settings (increasing PEEP from 8 to 10 cmH2O), and coordinating with nephrology regarding emergent CRRT initiation. Total critical care time today: 65 minutes (0840–0945), exclusive of procedure time.”

5. Common ICD-10 Diagnosis Codes That Support 99291

CPT 99291 is not linked to a specific ICD-10 diagnosis — the code is valid for any condition that meets the critical care definition. However, the following diagnoses frequently appear on 99291 claims and are recognized by Medicare and commercial payers as consistent with the medical necessity of critical care:

• A41.9: Sepsis, unspecified organism — the most common critical care diagnosis; requires vasopressor management and multi-system monitoring.
• A41.01 / A41.02: Sepsis due to MRSA / MSSA — requires IV antibiotic management and close monitoring.
• J96.00 / J96.01: Acute respiratory failure, unspecified / with hypoxia — often requires ventilator management (bundled).
• J96.20: Acute and chronic respiratory failure — common in COPD exacerbation with ventilatory failure.
• I21.9: Acute myocardial infarction, unspecified — with hemodynamic compromise and cardiogenic shock (I21.A9 + R57.0).
• R57.0: Cardiogenic shock — requires vasopressor support and invasive hemodynamic monitoring.
• R57.1: Hypovolemic shock — hemorrhagic or distributive shock requiring resuscitation.
• N17.9: Acute kidney injury, unspecified — when severe enough to require CRRT or emergent dialysis decisions.
• K72.00: Acute hepatic failure without coma — fulminant liver failure with systemic effects.
• G41.9: Status epilepticus, unspecified — refractory seizures requiring IV benzodiazepines, phenytoin titration.
• I26.09 / I26.99: Saddle pulmonary embolism / other PE with acute cor pulmonale — hemodynamically unstable PE.
• E87.01: Hyponatremia — severe symptomatic hyponatremia with neurological involvement.
• E10.10 / E11.10: Type 1/Type 2 DM with ketoacidosis, without coma — DKA requiring intensive insulin drip management.
• S09.90XA: Polytrauma — blunt or penetrating traumatic injury with multi-system involvement requiring emergent critical care in the ED or trauma bay.

6. Medicare Billing Rules, Same-Day E/M, and Concurrent Care

Critical Medicare Rule — “Once Per Day, Per Specialty Group”: CPT 99291 may be reported only once per calendar date per patient by the same physician or by physicians of the same specialty within the same group practice. A second intensivist from the same pulmonology/critical care group who comes to round on the patient later in the day does not bill another 99291 — their additional time is added to the aggregate, potentially supporting one or more units of 99292.

Critical Care and Other E/M Services on the Same Day (CMS Policy)

Since February 15, 2022, Medicare allows providers to bill a hospital E/M code (99221–99223 or 99231–99233) on the same calendar date as a critical care code, provided both of the following are true: (1) the E/M service was provided at a time when the patient did not yet require critical care (e.g., a morning rounding visit where the patient was stable), and (2) the patient’s condition deteriorated later in the day, necessitating critical care. The documentation for both the E/M visit and the critical care service must clearly reflect these distinct time periods and distinct clinical circumstances.

Important exception: If the patient already meets critical care criteria at the time of the initial encounter (e.g., presenting to the ED in septic shock), do not also bill an ED visit code. Report only the critical care code.

Concurrent Critical Care — Different Specialties

When two or more physicians from different specialties each provide critical care services to the same patient on the same day — and those services are distinct and non-duplicative — each specialty may independently bill 99291.

The documentation for each specialty must clearly delineate the unique clinical role: for example, a pulmonologist managing ventilatory failure and a nephrologist managing oliguric AKI requiring emergent CRRT may each bill 99291. Their notes must not overlap or duplicate each other’s clinical decision-making.

Critical Care in the Emergency Department

When a patient in the ED meets critical care criteria, only the critical care codes (99291/99292) should be billed — not the ED visit codes (99281–99285). This is one of the most common billing errors in emergency medicine. The critical care service captures the full complexity of the encounter, and billing both codes is improper. This rule holds true even if the critical care service was initiated in the waiting area, triage, or resuscitation bay.

Critical Care Crossing Midnight

When critical care services begin on one calendar date and are provided continuously past midnight, the entire time is billed on the date the services began. However, if there is a disruption in the service (i.e., the care is not continuous), the time on each calendar date is reported separately, and a new 99291 may be billed on the second date if at least 30 minutes of critical care are provided on that date.

7. Modifier Usage for CPT 99291

Modifier 25 (Significant, Separately Identifiable E/M)

Required by Medicare (and many commercial payers) when billing 99291 on the same day as a separately billable procedure. Appending modifier 25 to 99291 signals that the critical care service is a distinct, medically necessary service above and beyond the procedure performed. Example: A physician provides 45 minutes of critical care to a patient in septic shock and then performs central line placement (CPT 36556). Bill 99291-25 and 36556. Note: CPT does not require modifier 25 for critical care paired with non-bundled procedures, but Medicare does.

Modifier 57 (Decision for Major Surgery)

Use modifier 57 on 99291 when the critical care encounter results in the decision to perform a surgical procedure with a 90-day global period. Example: A surgeon evaluates a patient with an acute abdomen consistent with perforated viscus (septic shock) and decides to take the patient emergently to the OR for exploratory laparotomy. The critical care service with modifier 57 documents that the encounter constituted the pre-operative decision-making.

Modifier FS (Split or Shared E/M Visit)

Effective January 1, 2022, critical care visits may be furnished as split or shared visits between a physician and a non-physician practitioner (NPP) of the same group. When a split/shared critical care service is provided, the practitioner who furnishes more than half of the cumulative critical care time (the “substantive portion”) reports the critical care codes with modifier FS. The other practitioner does not separately bill. The 104-minute rule for Medicare still applies to the aggregate time for split/shared critical care.

Modifier GC (Teaching Physician)

Required when a teaching physician involves a resident in the delivery of critical care. The teaching physician must be present for the entire period of critical care being billed — not just for key portions. Unlike other E/M services, the teaching physician cannot count only a portion of the time. Resident time alone, without the teaching physician present, cannot be counted toward critical care time.

Modifier 24 (Unrelated E/M During Global Period)

A surgeon in a 10- or 90-day global surgical period who provides critical care for a condition completely unrelated to the procedure may append modifier 24 to 99291. Example: A cardiothoracic surgeon who performed a CABG two weeks ago is called to the ICU to manage the same patient for a new-onset septic shock from aspiration pneumonia — entirely unrelated to the cardiac surgery. Critical care for the sepsis (99291-24) would be separately billable.

8. Split/Shared Critical Care and Teaching Physician Rules

Split/Shared Critical Care (Effective January 1, 2022)

CMS now recognizes critical care as eligible for split/shared billing between a physician and an NPP (PA or NP) from the same group. Key rules include the following. Only one practitioner may report the critical care codes. The practitioner who provides more than 50% of the cumulative critical care time reports 99291 (and 99292 if applicable) with modifier FS. One of the practitioners must have face-to-face contact with the patient, but it does not have to be the one who reports the service. The substantive portion is defined entirely by time for critical care — there is no MDM-based substantive portion option, unlike other split/shared E/M services. The 104-minute threshold for Medicare still applies to the aggregated times of both practitioners combined.

Teaching Physician Billing Rules

In a teaching setting, the teaching physician must be present for the entire period of critical care being billed. This is a stricter requirement than the “key portion” rule that applies to other E/M services. The teaching physician may document their own note or co-sign and substantively augment the resident’s note. Time spent by the resident in the absence of the teaching physician cannot be counted. The teaching physician’s own documentation must clearly state their presence throughout the billed critical care period and reflect their active role in the clinical decision-making.

9. Comparison: 99291, 99292, and When to Use Standard E/M Instead

10. Complex Clinical Scenarios and Coding Examples

Scenario 1: Septic Shock in the ICU (Single Provider)

Patient: A 68-year-old admitted with urosepsis, now progressing to septic shock on day 2 with rising lactate (4.8), MAP dropping to 58 despite fluid resuscitation. Requires norepinephrine initiation. What the intensivist does: Spends 50 minutes at bedside and on the unit: reviewing cultures, repeat CBC/CMP, interpreting chest X-ray (new infiltrate, possible aspiration), adjusting norepinephrine, obtaining infectious disease consult by phone, placing central line (20 minutes — separate procedure), and documenting the note. Time calculation: 50 minutes of critical care + 20 minutes central line = 70 minutes total bedside time. Critical care time = 50 minutes (central line time excluded). Central line billed separately as 36556. Coding: 99291-25 + 36556. Rationale: Patient meets critical illness criteria (septic shock, imminent deterioration). Total critical care time = 50 minutes (within 30–74 minute range for 99291). Central line is not bundled and billed separately; modifier 25 on 99291 required by Medicare.

Scenario 2: Respiratory Failure Crossing Midnight (Time Aggregation)

Patient: A 54-year-old with acute hypoxic respiratory failure admitted through the ED, placed on BiPAP, intubated at 11:50 PM. Provider documents 35 minutes of critical care from 11:20 PM to 11:55 PM (Day 1). Next day, the same provider returns and spends an additional 45 minutes in the morning managing ventilator settings, vasopressors, and reviewing cultures (Day 2). Coding — Day 1: 99291 (35 minutes; intubation time of 10 minutes excluded — billed separately as 31500). Coding — Day 2: 99291 (45 minutes; new calendar date, new minimum of 30 minutes met).

Rationale: Each calendar date is evaluated independently. The service was not continuous across midnight (there was a gap when the intubation was performed and stabilization achieved). Each date has its own 99291.

Scenario 3: Concurrent Critical Care — Two Specialties

Patient: A 72-year-old with massive GI bleed causing hemorrhagic shock (Hgb 5.2, MAP 55) receiving packed red blood cells and vasopressors. Gastroenterologist and Intensivist are both involved. Gastroenterologist (GI): Provides 40 minutes of critical care managing the hemorrhage — reviews imaging, coordinates emergency endoscopy, discusses vasopressin use with surgery. Intensivist (Critical Care): Provides 55 minutes of critical care managing hemodynamic support — titrating vasopressors, adjusting fluid resuscitation, interpreting ABG for early ARDS management. Coding: GI bills 99291. Intensivist bills 99291. Both services are distinct and non-duplicative. Rationale: Different specialties managing distinct organ systems (GI source control vs. hemodynamic support) may each independently bill 99291. Both providers’ notes must clearly define their separate roles and time.

Scenario 4: Time Below Threshold — Bill Standard E/M Instead

Patient: A 60-year-old in the MICU on day 5 of sepsis, now hemodynamically stable on weaning doses of vasopressors. The physician rounds, reviews labs, adjusts the antibiotic regimen, and documents the visit. Time spent: 22 minutes. Coding: 99232 (Subsequent Hospital Care, Moderate MDM — prescription drug management: antibiotic adjustment). Rationale: Even though the patient is in the ICU, the patient is no longer meeting critical care criteria (hemodynamically stable, improving). Furthermore, 22 minutes is below the 30-minute minimum for 99291. The appropriate code is a standard subsequent hospital care code based on MDM or time.

Scenario 5: Split/Shared Critical Care with NP

Patient: A 58-year-old in respiratory failure on mechanical ventilation — Day 3. NP (same group as physician): Provides 45 minutes of critical care in the morning — ventilator management review, labs, family discussion documentation, order entry. Attending Physician: Provides 35 minutes of critical care in the afternoon — bedside assessment, reviewing worsening hemodynamics, making decision to add vasopressor. Combined time: 80 minutes total (CPT: 99291 + 99292; Medicare: 99291 only — 80 minutes does not reach 104). Coding (Medicare): 99291-FS billed under the physician’s NPI (physician provided the substantive portion = 35 min vs. NP’s 45 min — NP provided more time; if NP provided the substantive portion, bill under NP’s NPI). Correction: In this scenario, the NP provided more time (45 min). The NP bills 99291-FS under their own NPI. The physician does not separately bill. For Medicare, 80 total minutes = 99291 only (below 104-minute threshold). For CPT/commercial, 80 minutes = 99291 + 99292 × 1.

11. Top Audit Triggers and How to Avoid Them

The OIG, RAC auditors, and MACs have consistently identified the following patterns as high-risk for CPT 99291:

1. Billing 99291 without documenting total time. This is the single most common reason for claim denial and recoupment. Solution: Every critical care note must include a clear, specific time statement. Use EHR time-tracking tools or manually document start and stop times.
2. Billing 99291 for a stable ICU patient. Location does not determine billing eligibility. A post-operative patient sleeping comfortably in the ICU the day after uncomplicated surgery does not meet critical care criteria. Solution: Train providers to distinguish between critical illness (imminent deterioration risk, organ failure) and critical care location.
3. Billing 99291 + 99292 for Medicare before 104 minutes. The CPT midpoint rule does not apply to Medicare. Solution: Implement payer-specific edits in your billing system to flag Medicare claims where 99292 is billed before the 104-minute threshold is reached.
4. Billing bundled procedures separately alongside 99291. Ventilator management codes, pulse oximetry, and gastric intubation cannot be billed separately when 99291 is on the same claim. Solution: Build claim-level edits to reject bundled procedure codes when 99291 is present.
5. Counting nursing time or resident-only time toward the critical care total. Only the physician’s or supervising QHP’s direct time counts. Solution: Educate residents and NPs to document their time separately, and ensure attending physicians document their own independent time in all notes.** **
6. Duplicate billing of 99291 by two providers from the same group and specialty. Within the same specialty group, only the total time is aggregated — 99291 is billed once, with additional time supporting 99292. Solution: Implement same-day, same-specialty review in your charge-capture or coding workflow.
7. Using copy-forward documentation in the EHR. Identical critical care notes across multiple days are a clear audit flag. Solution: Critical care notes must be individualized each day, reflecting the current clinical situation, new data, and the day’s specific management decisions.