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Official Description

Insertion, subcutaneous cardiac rhythm monitor, including programming

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 33285 refers to the procedure of inserting a subcutaneous cardiac rhythm monitor (ICM), which is a device designed to continuously monitor the heart's rhythm over an extended period. This device functions similarly to a long-term Holter monitor, specifically aimed at detecting episodes of atrial fibrillation. The ICM utilizes automated algorithms to identify abnormal QRS signals, which are indicative of irregular heart rhythms. One of the key features of this device is its ability to transmit patient data wirelessly to healthcare providers, allowing for remote monitoring and timely intervention if necessary. The use of a subcutaneous cardiac rhythm monitor is particularly indicated for patients who present with transient symptoms that may suggest a cardiogenic origin, such as dizziness, syncope (loss of consciousness), chest pain, and palpitations. These symptoms may place patients at a higher risk for serious conditions like atrial fibrillation, stroke, or heart failure. The procedure not only involves the physical insertion of the device but also includes programming it to ensure accurate data collection and performance verification, making it a comprehensive approach to cardiac monitoring.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The insertion of a subcutaneous cardiac rhythm monitor (ICM) is indicated for patients who are suspected to be at high risk for atrial fibrillation, stroke, or heart failure. This suspicion arises from transient symptoms that may suggest a cardiogenic origin. The specific indications include:

  • Dizziness - Episodes of lightheadedness or unsteadiness that may indicate irregular heart rhythms.
  • Syncope - Instances of fainting or loss of consciousness that could be related to cardiac events.
  • Chest Pain - Discomfort or pain in the chest that may signal underlying heart issues.
  • Palpitations - Awareness of an irregular heartbeat, which can be a sign of atrial fibrillation or other arrhythmias.

2. Procedure

The procedure for the insertion of a subcutaneous cardiac rhythm monitor involves several detailed steps to ensure proper placement and functionality of the device. The steps are as follows:

  • Preparation of the Insertion Site - The parasternal area of the anterior chest is thoroughly prepped to maintain a sterile environment. A local anesthetic is then injected at the selected insertion site to minimize discomfort during the procedure.
  • Incision Creation - The skin at the insertion site is pinched to form a tent, allowing for easier access to the subcutaneous tissue. An incision tool is introduced at a 90° angle into the tented skin, penetrating to its full depth before being withdrawn.
  • Insertion of the ICM - The insertion tool, which is preloaded with the ICM, is introduced through the incision. The tool is rotated to create a pocket within the subcutaneous tissue, facilitating the placement of the device.
  • Deployment of the Device - The insertion tool is positioned to deliver the ICM into the created pocket. A plunger is attached to the tool and used to deploy the ICM into the subcutaneous space. Gentle pressure is applied over the skin to hold the ICM in place while the insertion tool is carefully removed.
  • Programming the Device - Once the ICM is in place, it is programmed to begin data collection. The performance of the device is verified to ensure it is functioning correctly before the skin incision is closed.

3. Post-Procedure

After the insertion of the subcutaneous cardiac rhythm monitor, patients can expect a period of monitoring to ensure the device is functioning as intended. Post-procedure care may include instructions on how to care for the insertion site, signs of potential complications to watch for, and follow-up appointments for data review and device performance checks. Patients should be advised to avoid strenuous activities that may impact the insertion site during the initial recovery phase. Regular follow-up with healthcare providers is essential for ongoing assessment of the device's data and the patient's cardiac health.

Short Descr INSJ SUBQ CAR RHYTHM MNTR
Medium Descr INSERTION SUBQ CARDIAC RHYTHM MONITOR W/PRGRMG
Long Descr Insertion, subcutaneous cardiac rhythm monitor, including programming
Status Code Active Code
Global Days 000 - Endoscopic or Minor Procedure
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 1 - Statutory payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Device-intensive procedure added to ASC list in CY 2008 or later; paid at adjusted rate.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) none
MUE 1
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
GC This service has been performed in part by a resident under the direction of a teaching physician
KX Requirements specified in the medical policy have been met
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
CR Catastrophe/disaster related
ET Emergency services
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
25 Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service: it may be necessary to indicate that on the day a procedure or service identified by a cpt code was performed, the patient's condition required a significant, separately identifiable e/m service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. a significant, separately identifiable e/m service is defined or substantiated by documentation that satisfies the relevant criteria for the respective e/m service to be reported (see evaluation and management services guidelines for instructions on determining level of e/m service). the e/m service may be prompted by the symptom or condition for which the procedure and/or service was provided. as such, different diagnoses are not required for reporting of the e/m services on the same date. this circumstance may be reported by adding modifier 25 to the appropriate level of e/m service. note: this modifier is not used to report an e/m service that resulted in a decision to perform surgery. see modifier 57 for significant, separately identifiable non-e/m services, see modifier 59.
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
53 Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
56 Preoperative management only: when 1 physician or other qualified health care professional performed the preoperative care and evaluation and another performed the surgical procedure, the preoperative component may be identified by adding modifier 56 to the usual procedure number.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
AI Principal physician of record
AO Alternate payment method declined by provider of service
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
FB Item provided without cost to provider, supplier or practitioner, or full credit received for replaced device (examples, but not limited to, covered under warranty, replaced due to defect, free samples)
FS Split (or shared) evaluation and management visit
GA Waiver of liability statement issued as required by payer policy, individual case
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
GZ Item or service expected to be denied as not reasonable and necessary
LT Left side (used to identify procedures performed on the left side of the body)
Q0 Investigational clinical service provided in a clinical research study that is in an approved clinical research study
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q5 Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
RT Right side (used to identify procedures performed on the right side of the body)
SG Ambulatory surgical center (asc) facility service
X2 Continuous/focused services: for reporting services by clinicians whose expertise is needed for the ongoing management of a chronic disease or a condition that needs to be managed and followed with no planned endpoint to the relationship; reporting clinician service examples include but are not limited to: a rheumatologist taking care of the patient's rheumatoid arthritis longitudinally but not providing general primary care services
X3 Episodic/broad services: for reporting services by clinicians who have broad responsibility for the comprehensive needs of the patient that is limited to a defined period and circumstance such as a hospitalization; reporting clinician service examples include but are not limited to the hospitalist's services rendered providing comprehensive and general care to a patient while admitted to the hospital
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
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2019-01-01 Added Added
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