Can 99233 and 99291 be billed together?

Yes, CPT codes 99233 (subsequent hospital care) and 99291 (critical care) can be billed together on the same calendar day, but only if the patient's condition required a separate, distinct non-critical evaluation and management (E/M) service before they deteriorated or required critical care later in the same day.

Key Conditions for Billing Together

• Separate Encounters: The patient must not have required critical care during the initial 99233 visit; the critical status must develop later in a separate encounter.
• Medically Necessary: Both services must be fully documented and medically necessary on their own merits.
• Modifier Usage: Appending modifier 25 to the non-critical E/M service (99233) is frequently required by payers to indicate a significant, separately identifiable service performed on the same date.
• No Time Overlap: Time spent providing the standard E/M service cannot be counted toward the critical care time reported under CPT Code 99291.

For further guidance, you can review the discussion on Hospitalist Billing or the AAPC Forum.

Yes, you can bill both 99233 (subsequent hospital inpatient care, high complexity) and 99291 (critical care, first 30–74 minutes) on the same day if the patient's condition changes and distinct, separate services are provided.

Billing Requirements

• Separate Times: The critical care time (99291) cannot count toward the time or tasks used to report the subsequent inpatient visit (99233).
• Clinical Change: There must be a documented change in the patient's condition that requires separate, medically necessary critical care intervention later in the same day.
• Modifier: Append modifier -25 to the E/M code (99233) to show it is a separate and distinct service from the critical care provided on the same calendar date by the same provider.
• Documentation: Record separate start and stop times for the critical care portion, and clearly separate the clinical notes for both encounters.

CPT code 99291 is billed for the first 30 to 74 minutes of critical care evaluation and management for a critically ill or critically injured patient.

Time Requirements

• Minimum threshold: You must spend at least 30 cumulative minutes providing critical care on a single calendar date to report CPT Code 99291.
• Maximum duration: The code covers time from 30 up to 74 minutes. Time of 75 minutes or more transitions into add-on code 99292 (though Medicare rules may differ slightly regarding exact increments).
• Cumulative time: Non-continuous blocks of time on the same calendar date by the same provider or same specialty group can be added together.

Clinical Criteria

• Acute impairment: The patient must face acute impairment of one or more vital organ systems with a high probability of imminent or life-threatening deterioration.
• Active management: Care requires high-complexity decision making and constant, active attention from the provider. Simply being in an ICU or placed on a ventilator does not automatically qualify.

Frequency and Limitations

• Once per day: 99291 can only be billed once per patient, per calendar date, by the same physician or physician group of the same specialty.
• Under 30 minutes: If total critical care time is less than 30 minutes, do not use 99291. Instead, bill a standard evaluation and management code (such as subsequent hospital care or emergency department visit) appropriate for the site of service.
• Inclusive procedures: Many routine services (such as interpretation of chest X-rays, blood gases, data interpretation, or vascular access) are bundled into critical care codes and cannot be billed separately.

CPT code 99233 is billed for a subsequent hospital inpatient or observation care visit that requires high-complexity medical decision-making (MDM) or a minimum of 50 total minutes of provider time on the date of the encounter.

Core Billing Requirements

You can select code 99233 using one of two alternative pathways (you do not need to meet both, but your documentation must clearly support the chosen pathway):

• Medical Decision Making (MDM): Requires a medically appropriate history and exam, paired with High Complexity MDM (e.g., high risk of morbidity from additional diagnostic testing or treatment, high complexity of data reviewed, and severe/unstable presenting problems).
• Time-Based Reporting: Requires spending 50 minutes or more of total time on the date of the encounter. This includes face-to-face and non-face-to-face time performed on the same calendar day, such as reviewing charts, talking with the patient or family, coordinating care, and writing the documentation.

Key Documentation & Usage Rules

• Setting: Applies to both inpatient hospital units and observation status patients (following the American Medical Association E/M updates which merged observation care into inpatient codes).
• Frequency: Can only be billed once per day per patient by the same physician (or a physician of the same specialty in the same group practice).
• Medical Necessity: The patient's clinical condition on that specific day must justify a high level of care, such as acute clinical instability, significant new complications, or complex post-surgical management.

You can read a detailed breakdown via this CPT Code 99233 Guide for Physicians and Billers.

CPT code 99291 does not require a modifier in standard billing, but specific clinical scenarios require modifiers like FS, FT, or 25.

When Modifiers Are Required

• Modifier FS: Append this modifier for split or shared critical care services when a physician and a non-physician practitioner in the same group combine their time and the billing provider performs more than half of the total time.
• Modifier FT: Append this modifier when critical care services are provided during a global surgical period but are completely unrelated to the surgical procedure.
• Modifier 25: Use this modifier if you perform a separate, significant, non-bundled procedure on the same day as the critical care service, depending on payer rules.