Implantable Loop Recorder Coding

implantable loop recorder coding
A loop recorder is inserted under the skin to monitor the heart’s electrical activity.
Article at a glance on implantable loop recorder coding

Demand for Implantable Loop Recorders is on the Rise

The demand for cardiovascular devices continues to rise, and implantable loop recorders are included in this increased demand due to the growing number of cardiac conditions caused by irregularity in heart rhythms and other chronic diseases. 

Fortune Business Insights states that the global cardiovascular devices market size is projected to grow from $54.08 billion in 2021 to $86.27 billion in 2028. Technavio reports that the anticipated market share for implantable loop recorders will increase by $606.31 million from 2021 to 2026. With these anticipated changes, medical coders can expect to see new and revised codes and guidelines for reporting these services. 

What Coders Should Know About Implantable Loop Recorders

Coding for implantable loop recorders begins with knowing what the device is used for, how the procedure is performed, and how the device is managed once inserted. Reporting the correct procedure codes also requires understanding the CPT coding guidelines related to implantable loop recorders. Follow along to learn more. Finally, test your coding skill on the three related coding exercises.


Other names for an implantable loop recorder are a subcutaneous cardiac rhythm monitor and an insertable cardiac event recorder. CPT uses the term “subcutaneous cardiac rhythm monitor” in its code descriptors.


What is an Implantable Loop Recorder and Why Might One be Recommended?

An implantable loop recorder (ILR) is a monitoring device placed under the skin to monitor the heart’s electrical activity over an extended period. According to Johns Hopkins Medicine, a physician may recommend this device for patients who experience symptoms for which the cause cannot be determined through other tests. The symptoms include fainting, palpitations, very fast or slow heartbeats, and hidden rhythms that can lead to strokes.

For example, a physician suspects an arrhythmia, or irregular heartbeat, in a patient presenting with repeated episodes of fainting (also known as syncope). Repeated fainting can affect a person’s physical and emotional health and result in sudden cardiac death. Therefore, it is critical that the cause be determined so appropriate treatment may begin.

The first test a physician will likely begin with is an electrocardiogram (ECG) to record the heart rhythm. An ECG records the heart rhythm for only a few seconds, so it may not be enough to determine the cause of syncope. Therefore, according to the National Heart, Lung, and Blood Institute, other tests may need to be performed including Holter monitoring, tilt-table testing, or electrophysiologic studies. If the direct cause of the syncope cannot be diagnosed after these tests, an implantable loop recorder may be the next best option.

Once the arrhythmia is identified, a life-saving device, such as a pacemaker or implantable cardioverter-defibrillator (ICD), may become necessary to correct the condition. At the time that one of these devices is inserted, the loop recorder can be removed.

Difference Between Implantable Loop Recorders and Portable Heart Rhythm Monitors

An implantable loop recorder is similar to a portable heart rhythm monitor such as a Holter monitor in that they both are ECG monitoring devices used for unexplained symptoms. However, a Holter monitor is a portable device used mostly for short periods of time. An ILR, on the other hand, is better used for patients who have less frequent symptoms and can help the physician determine the cause of the symptoms.

Below is a short video explaining an implantable loop recorder procedure.

A 3-minute video of an insertable cardiac monitor (loop recorder) procedure

Insertion of Implantable Loop Recorder Procedure

Insertion of an implantable loop recorder/cardiac rhythm monitor is a quick and simple procedure that takes less than 15 minutes to perform. According to the National Library of Medicine, an electrophysiologist, a specialized type of cardiologist, usually performs the procedure as an outpatient procedure.

The physician injects lidocaine or other numbing medication into the left side of the body at about the second or third rib level over the heart. A small incision is made under the skin, and a pocket is created to insert the loop recorder. The recorder is about the size of a USB memory stick and contains two self-contained electrodes. Once the recorder is inserted into the pocket, it is activated and programmed for data collection. The incision is then closed, generally with sutures or staples.

Programming and Monitoring of the Device

Once the loop recorder device has been inserted, it must be programmed and monitored. Initial programming is performed at the time of the implant. The physician sets and activates the heart rate ranges on the device. Programming may also be necessary at a later date if the device needs a change in its functions.

Electrocardiographic  (ECG) tracings
Example of an ECG tracing as identified by an implantable loop recorder.

Continuous monitoring of the device is essential. Data is gathered from the implanted device as the patient undergoes regular daily activity. When there is an abnormal heart rhythm, the remote device automatically records it based on the algorithms and QRS signals. The patient may also activate the device at the time of the episode. These tracings are then transmitted to a receiving station, where a technician interprets the electrocardiographic (ECG) tracing, any reported symptoms, and the length of duration, which assists the physician in making a diagnosis of the underlying problem.

Although monitoring can be done in the office, remote monitoring is the standard of care. In-person monitoring involves the clinician holding a programmer over the device to retrieve the stored data. With remote monitoring, the cardiac device transmits data to the clinic by way of a Wi-FI or cellular connection. Retrieved data must be reviewed at least once every 30 days.

Removal of an Implantable Loop Recorder 

Removal of an implantable loop recorder is typically advised at the point when the ILR batteries can no longer record any information. This is usually at about the 3-year mark, as batteries typically only last about three years.

Other times, when the ILR detects significant rhythm problems or any cardiac events related to symptoms such as syncope or palpitations, the device may be removed sooner and replaced with a pacemaker or implantable cardiac defibrillator. 

If the cause of the symptoms is found to be something other than a cardiac condition, an appropriate physician will treat it, and the patient may choose to leave the ILR device in place or remove it.

Additional reasons a rhythm monitor may need to be removed include complications such as pain at the implant site, infection of the local pocket, or a local skin reaction to the device. Also, poor R-wave sensing, a rare complication, may require moving the device to another location. 

Removing an implantable loop recorder is performed in the same manner as an insertion. The cardiologist injects a local anesthetic into the chest area to numb the pain and then makes a small cut to remove the ILR. The incision is then closed.

subcutaneous cardiac rhythm monitor coding (implantable loop recorder)

Loop Recorder Implant Procedure/SCRM Coding

Insertion and Removal

In the CPT codebook, an implantable loop recorder is referred to as a subcutaneous cardiac rhythm monitor (SCRM). SCRM codes are listed under Surgical Procedures on the Cardiovascular System, specifically under Surgical Procedures on the Heart and Pericardium. 

These codes are classified as to whether the device is being inserted or removed:

  • 33285, Insertion, subcutaneous cardiac rhythm monitor, including programming
  • 33286, Removal, subcutaneous cardiac rhythm monitor

The initial insertion includes programming. According to the CPT coding guidelines, subsequent electronic analysis, and/or reprogramming should be reported with 93285, 93291, or 93298.

Programming and Interrogation of Cardiac Rhythm Monitor

CPT Category I codes for programming and Interrogation (monitoring) of cardiac rhythm monitor devices are listed under Cardiovascular Procedures, specifically under Implantable, Insertable, and Wearable Cardiac Device Evaluations. There is also a Category III code reportable for programming the SCRM and a HCPCS Level II code reportable for the interrogation of the SCRM. These are explained below.

Programming the SCRM

Programming of the subcutaneous cardiac rhythm monitor is reported according to whether the service is performed in person or remotely.

  • 93285, Programming device evaluation (in person) with iterative adjustment of the implantable device to test the function of the device and select optimal permanent programmed values with analysis, review, and report by a physician or other qualified health care professional; subcutaneous cardiac rhythm monitor system
  • 0650T, Programming device evaluation (remote) of subcutaneous cardiac rhythm monitor system, with iterative adjustment of the implantable device to test the function of the device and select optimal permanently programmed values with analysis, review, and report by a physician or other qualified health care professional

According to the CPT coding guidelines:

  • 93285 cannot be reported with 33285, 93279-93284, 93291, or 0650T.
  • 0650T cannot be reported in conjunction with 33285, 93260, 93279, 93280, 93281, 93282, 93284, 93285, or 93291.

Note: Codes 93260, 93279-93284 refer to the programming of pacemakers or defibrillators.

Code 93285 requires a modifier according to whether it is the professional or technical component of the service. For example, if only the professional component is performed, assign 93285-26; for only the technical component, assign 93285-TC. If both components are performed, report 93285 without a modifier. 

A physician or other qualified healthcare professional must personally perform the professional component of the work to report the professional component-only codes.

The technical component-only code requires that the procedure be performed under the physician’s general supervision and control. The physician does not need to be personally present during the procedure.

Interrogation of the SCRM

Interrogation codes are reported based on whether the monitoring is performed in person or remotely and whether the professional or technical component of the service is performed.

  • 93291, Interrogation device evaluation (in person) with analysis, review, and report by a physician or other qualified health care professional, includes connection, recording, and disconnection per patient encounter; subcutaneous cardiac rhythm monitor system, including heart rhythm-derived data analysis

Code 93291 requires a modifier (-26, -TC) according to whether it is the professional or technical component of the service. If both components are performed, 93291 is reported without a modifier. 

  • 93298, Interrogation device evaluation(s), (remote) up to 30 days; subcutaneous cardiac rhythm monitor system, including analysis of recorded heart rhythm data, analysis, review(s), and report(s) by a physician or other qualified health care professional
  • G2066, Interrogation device evaluation(s), (remote) up to 30 days; implantable cardiovascular physiologic monitor system, implantable loop recorder system, or subcutaneous cardiac rhythm monitor system, remote data acquisition(s), receipt of transmissions and technician review, technical support and distribution of results

Codes 93298 and G2066 do not need modifiers -26 or TC appended, as their code descriptors already indicate the technical or professional component.

According to the coding guidelines:

  • Do not report 93291 in conjunction with 33285, 93288-93290, 93298, 0650T
  • Do not report 93298 in conjunction with 33285, 93291, 93297, 99091, 99454
  • Report 93298 only once per 30 days per patient and not less than 10 days

Test Your Coding Skill

Assign the correct procedure code for each of the following and review the answers and rationales below. 

#1. A 62-year-old female is seen by Dr. Blue, an electrophysiologist, for a new insertable cardiac event recorder after having unexplained syncope episodes and is suspected of cardiac arrhythmia. Dr. Blue anesthetized the patient’s chest area above the heart with injectable lidocaine and made a small incision in the skin. He then inserted and programmed the monitor before closing the area with two staples.  

#2. A patient with an implanted loop recorder presents today to the cardiologist for the removal of the device after having it in place for two years. The patient states he has experienced no syncope episodes since the device was inserted, and the device detected no cardiac arrhythmias. The cardiologist numbs the chest area with injectable lidocaine and creates an incision. The device is removed and the incision is sutured closed.

#3. A representative for the implantable loop recorder system manufacturer performs the technical remote monitoring of the loop recorder device during a 30-day period. Under the physician’s supervision, the rep distributes the results to the physician’s office, and the physician analyzes the results and writes a report with the diagnosis of the underlying cause. How would the physician report for his portion of the service?

Answers and Rationales

#1. 33285

Rationale: One way to find the correct code in the CPT codebook is to go to the Index and look under Cardiac Event Recorder. The instructions tell us to see Subcutaneous Cardiac Rhythm Monitor System.” From there, it takes us to:

  • Insertion 33285
  • Interrogation Device Evaluation
    • In Person 93291
    • Remote 93298
  • Programming Device Evaluation
    • In Person 93285
    • Remote 0650T
  • Removal 33286

Since this is an insertion of a cardiac rhythm monitor, we need to go to 33285 in the Tabular to verify our correct code as:

33285, Insertion, subcutaneous cardiac rhythm monitor, including programming

The coding guidelines state, Initial insertion includes programming. For subsequent electronic analysis and/or reprogramming, see 93285, 93291, 93298. Therefore, we should not assign a code for the programming of the device.

#2. 33286

Rationale: The device detected no arrhythmias, so the patient did not require a pacemaker or implantable cardioverter-defibrillator to correct the condition. Hence, the patient elected to have the device removed.

In the Index, if we look up Loop Recorder System, Implantable, it instructs us to see Subcutaneous Cardiac Rhythm Monitor System. Under this listing, it shows us Removal 33286. We can verify this code in the Tabular as:

33286, Removal, subcutaneous cardiac rhythm monitor

#3. 93298

Rationale: The physician performed only the professional review and interpretation of the remote interrogation device evaluation during a 30-day period. The technical portion of the monitoring was performed by the manufacturer’s rep. Therefore, the physician may only report for the professional component of the service.  

In the Index, look up Monitoring/Cardiac/ Subcutaneous Cardiac Rhythm Monitor System/Interrogation device evaluation(s), (remote) up to 30 days, 93298. In the Tabular, we can verify this code as:

93298, Interrogation device evaluation(s), (remote) up to 30 days; subcutaneous cardiac rhythm monitor system, including analysis of recorded heart rhythm data, analysis, review(s), and report(s) by a physician or other qualified health care professional

CPT 93298 is to be reported once for each 30-day period on the 31st day. There is no need to append modifier -26 to 93298 as the code descriptor indicates it is the professional component of the service. A device industry representative under the direction of the physician who performed the technical component of the service would report G2066.

Codes that May Support SCRM Codes

According to Medtronic, a leading maker of medical devices and subcutaneous cardiac rhythm monitors, the following medical codes may support subcutaneous cardiac rhythm monitors:

ICD-10-CM codes:
G45.0-G45.3, G45.8-G45.9, Transient cerebral ischemia attacks and related syndromes
I47.0-I47.9, Paroxysmal tachycardia
I48.0-I48.19, Atrial fibrillation and flutter
I49.01-I49.9, Other cardiac arrhythmias
I63.0-I63.9, Cerebral infarction
I69.30-I69.998, Sequela of cerebral infarction
R00.2, Palpitations
R06.02, Shortness of breath
R07.89, Other chest pain (includes chest pressure, discomfort, and tightness)
R07.9 Chest pain, unspecified
R42, Dizziness and giddiness
R53.83, Other fatigue (includes lack of energy, tiredness
R55, Syncope and collapse (pre-syncope)
R94.31, Abnormal electrocardiogram (ECG) (EKG)
Z79.01, Long-term (current) use of anticoagulants
Z86.73 Personal history of transient ischemic attack (TIA), and cerebral infarction without residual deficits

HCPCS code:
C1764, Event recorder, cardiac (implantable)

The above is not an all-inconclusive list.

3 coding exercises on subcutaneous cardiac rhythm monitors/implantable loop recorders

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