Moderate Sedation FAQ

With the release of the 2006 book, the American Medical Association (AMA) CPT manual further defined the concept of Conscious Sedation, which is now termed Moderate (Conscious) Sedation (MCS) to distinguish this service within the spectrum of sedation. Moderate (Conscious) Sedation does not include minimal sedation or anxiolysis, deep sedation or, anesthesia services.

In 2017 the Moderate (Conscious) Sedation codes 99143-99150, were deleted and replaced with the codes the code series 99151-99157.

Moderate (Conscious) Sedation [MCS] is a drug-induced depression of consciousness. The patient maintains the ability to respond purposefully to verbal direction, either alone or accompanied by light tactile stimulation. Interventions are not required to maintain cardiovascular function or a patent airway, and spontaneous ventilation is adequate.

According to CPT:

Preservice Work

The preservice activities required for moderate sedation are included in the work described by each code (99151, 99152, 99153, 99155, 99156, 99157) and are not reported separately. The following preservice work components are not included when determining intraservice time for reporting:

• Assessment of the patient’s past medical and surgical history with particular emphasis on cardiovascular, pulmonary, airway, or neurological condition;
• Review of the patient’s previous experiences with anesthesia and/or sedation;
• Family history of sedation complications;
• Summary of the patient’s present medication list;
• Drug allergy and intolerance history;
• Focused physical examination of the patient with an emphasis on:
  • Mouth, jaw, oropharynx, neck, and airway for Mallampati score assessments;
  • Chest and lungs;
  • Heart and circulation
• Vital signs, including heart rate, respiratory rate, blood pressure, and oxygenation with end-tidal CO2 when indicated;
• Review of any pre-sedation diagnostic tests;
• Completion of a pre-sedation assessment form (with an American Society of Anesthesiologists [ASA] Physical Status classification);
• Patient informed consent;
• Immediate pre-sedation assessment prior to first sedating doses; and
• Initiation of IV access and fluids to maintain patency.

Intraservice Work

Intraservice time is used to determine the appropriate CPT code to report moderate sedation services:

• Begins with the administration of the sedating agent(s);
• Ends when the procedure is completed, the patient is stable for recovery status, and the physician or other qualified health care professional providing the sedation ends personal continuous face-to-face time with the patient;
• Includes ordering and/or administering the initial and subsequent doses of sedating agents;
• Requires continuous face-to-face attendance of the physician or other qualified health care professional;
• Requires monitoring patient response to the sedating agents, including:
  • Periodic assessment of the patient;
  • Further administration of agent(s) as needed to maintain sedation; and
  • Monitoring of oxygen saturation, heart rate, and blood pressure.

If the physician or other qualified health care professional who provides the sedation services also performs the procedure supported by sedation (99151, 99152, 99153), they will supervise and direct an independent trained observer who assists in patient monitoring throughout the procedure.

Post-service Work

The post-service activities required for moderate sedation are included in the work described by each code (99151, 99152, 99153, 99155, 99156, 99157) and are not reported separately. Once continuous face-to-face time with the patient has ended, additional face-to-face time is not added to the intraservice time; however, it is considered part of the post-service work. 

The following post-service work components are not included when determining intraservice time for reporting:

• Assessment of the patient’s vital signs, level of consciousness, neurological, cardiovascular, and pulmonary stability in the post-sedation recovery period;
• Assessment of the patient’s readiness for discharge following the procedure;
• Preparation of the documentation regarding sedation service; and
• Communication with family/caregiver regarding sedation service.

Post-service work/times are not used to select the appropriate code.

CPT Code 99151 describes Moderate Sedation provided by the same physician or other qualified health care professional performing the diagnostic or therapeutic service that the sedation supports for patients younger than 5 years of age for the first 15 minutes of intraservice time. There is also the requirement of an independent trained observer to assist in the monitoring of the patient’s consciousness and physiological status, and who has no other duties (e.g., assisting at surgery) during the procedure.

CPT Code 99152 describes Moderate Sedation provided by the same physician or other qualified health care professional performing the diagnostic or therapeutic service that the sedation supports, for patients 5 years of age or older for the first 15 minutes of intraservice time. There is also the requirement of an independent trained observer to assist in the monitoring of the patient’s consciousness and physiological status, and who has no other duties (e.g., assisting at surgery) during the procedure.

CPT Code 99153 describes Moderate Sedation provided by the same physician performing the diagnostic or therapeutic service that the sedation supports for each additional 15 minutes of intraservice time. There is also the requirement of an independent trained observer to assist in the monitoring of the patient’s consciousness and physiological status, and who has no other duties (e.g., assisting at surgery) during the procedure.

Codes 99151-99153 describe Moderate (Conscious) Sedation services provided by the same physician who is also performing the procedure or diagnostic service for which the Moderate (Conscious) Sedation is needed. Codes 99155-99157 describe Moderate Sedation services provided by a physician other than the health care provider performing the diagnostic or therapeutic service for which the MCS is needed. Both sets of codes are then further delineated based on patient age and incremental time, as shown in FAQ 4.

CPT Code 99155 describes Moderate (Conscious) Sedation provided by a physician, other than the health care professional performing the diagnostic or therapeutic service that the sedation supports, for patients under 5 years of age, for the first 15 minutes of intraservice time.

CPT Code 99156 describes Moderate (Conscious) Sedation provided by a physician other than the health care professional performing the diagnostic or therapeutic service that the sedation supports, for patients age 5 years of age or older, for the first 15 minutes of intraservice time.

CPT Code 99157 describes each additional 15 minutes of intraservice time.

The intraservice time should be clearly documented in the ED chart.  For these codes, as described by CPT Assistant (February 2006), “Intraservice time starts with the administration of the sedation agent(s), requires continuous face-to-face attendance, and ends at the conclusion of personal contact by the physician providing the sedation.” The patient needs to be continuously monitored and reassessed. An independent, trained observer, who has no other duties during the procedure, must be present to assist in monitoring the patient when the physician is both performing the procedure and providing the MCS.

Repeat assessment of the patient and recovery, once personal contact is concluded, are not included in intraservice time. The total time of patient recovery may be documented in the nursing section of the patient record, the moderate sedation record, or in the physician note.

In October 2011 CPT Assistant indicated that the CPT standard for time measure does apply to the moderate (conscious) sedation codes. Per CPT, a unit of time is attained when the temporal midpoint has been passed (e.g., an hour is attained when 31 minutes have elapsed) UNLESS OTHERWISE SPECIFIED.

Moderate sedation is a time-based code with a specified unit of time of 15 minutes. However, the CPT 2022 coding instructions indicate that the patient’s chart must indicate a minimum of 10 minutes of intraservice time to report the initial Moderate Sedation codes 99151, 99152, 99155, and 99156. If the time threshold of 10 minutes has not been met, then the respective initial code is not reportable. Since CPT specifies 10 minutes as the minimum requirement of moderate sedation, the midpoint rule above does not apply to the Moderate Sedation initial time codes (99151, 99152, 99155 and 99156).

No. In 2012, CPT indicated that when using the code set that 99151-99153 replaced, it is understood that the physician will be performing a diagnostic/therapeutic procedure simultaneously. There is no need to subtract the procedure time from the Moderate Sedation time.

CPT states that, "A unit of time is attained when the midpoint has been passed.”  Therefore, to report the add-on codes to initial moderate sedation of 15 minutes, a total of 8 minutes of additional intraservice time must have occurred. These add-on codes are only reported after the time for the initial service has been met, which is now 15 minutes. Therefore, to report the initial and add-on code, at least 23 minutes of intraservice time must have occurred to report both. For the initial codes, a minimum of 10 minutes of intraservice time must be performed.

In previous versions of CPT, Appendix G listed procedures that incorporated moderate sedation and, therefore, moderate sedation could not be reported with those procedures. In 2017 appendix G was removed, and therefore moderate sedation can be reported with other procedure codes, including those that were formally in Appendix G (99151, 99152, 99153, 99155, 99156 and 99157).

The MCS services described by codes 99151-99153 require the presence of an independent trained observer who has no other duties (e.g., assisting at surgery) during the procedure to assist in monitoring the patient’s level of consciousness and physiologic status.

The 2023 MCS codes (99143-99150) continue to include all six possible routes of administration: intramuscular, intravenous, oral, rectal, intranasal, and inhalation.

Documentation should include the name of the procedure, medication names, dosages, routes of administration, who administered the medication(s) (physician or observer), notations of ongoing assessments and vital signs monitoring during MCS. Documentation of this by nursing in a separate area of the chart does not need to be copied into the physician’s chart.