CurrentCentenePolicy CP.MP.243

Implantable Loop Recorder (ILR) / Implantable Cardiac Monitor (ICM)

Defines medical necessity criteria, coding implications, and background evidence for implantable loop recorders for detection of cardiac arrhythmias for members of Centene-affiliated health plans.

Policy Summary

PayerCentene

PolicyImplantable Loop Recorder (ILR) / Implantable Cardiac Monitor (ICM)

Policy CodePolicy CP.MP.243

Change TypeNo material clinical or coverage changes

Effective Date

Next Review Date

Key ActionObtain prior authorization and document that 30-day external ambulatory monitoring was inconclusive or contraindicated when required.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

2-4 yrsILR battery longevity

20-40%Cryptogenic stroke proportion

55% vs 19%Diagnostic yield (ICM vs conventional)

5 codesCPT codes referenced

Medical Necessity and Coverage Criteria

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Section I indications: A. Suspected silent atrial fibrillation (AF) in the setting of cryptogenic stroke when 30-day external ambulatory monitoring is inconclusive or contraindicated; B. Suspected or known ventricular arrhythmia when 30-day external ambulatory monitoring is inconclusive or contraindicated; C. History of structural or infiltrative heart disease (e.g., valvular aortic stenosis, hypertrophic cardiomyopathy, cardiac sarcoidosis, congenital heart disease) AND both of the following: (1) high risk for arrhythmias (e.g., family history, symptoms, anatomy of structural heart disease) AND (2) 30-day external ambulatory monitoring (e.g., external loop recorder) is inconclusive or contraindicated; D. Recurrent, unexplained syncope or presyncope AND both of the following: (1) cardiac arrhythmia is suspected and external ambulatory monitoring (e.g., 30-day external loop recorder) is inconclusive or contraindicated; and (2) symptoms are infrequent (e.g., less than once per month).

Exact wording from policy section I.

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Section II — May Be Considered After Secondary Medical Director Review

May be considered medically necessary when ALL of the following are met and after mandatory secondary medical director review:

Section II group: A. Presenting condition meets one of: (1) single, abrupt episode of unexplained syncope without prodrome resulting in injury/trauma; (2) significant, recurrent and unexplained palpitations; B. Serious cardiac arrhythmia is suspected; C. 30-day external ambulatory monitoring (e.g., external loop recorder) is inconclusive or contraindicated; D. Symptoms are infrequent (e.g., less than once per month).

Secondary medical director review required per policy.

Section III — Replacement Device

Replacement of an ILR/ICM may be considered medically necessary when ALL of the following are met:

Replacement criteria: Existing monitor is no longer functioning and is outside its warranty (e.g., device is nearing the end of its battery life) AND the request meets the applicable Section I or II criteria.

Applies to replacement devices only.

Administrative: The policy has been updated to remove ICD-10 diagnosis code lists from this document; coding and billing references are provided separately in the coding section. This portion of the policy does not include an explicit clinical exclusion list—coverage determinations continue to be made using the stated medical necessity criteria and applicable plan rules.

Coverage decisions: All determinations under this policy are subject to the member's specific coverage documents and the plan's terms, conditions, exclusions, and limitations. This clinical policy is a medical necessity guide and does not guarantee payment or replace the contract language in the member's evidence of coverage.

Billing and Coding

Referenced CPT CodesCPT

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

Referenced HCPCS/G-Codes and DescriptorsHCPCS

C1764	Event recorder, cardiac (implantable).
E0616	Implantable cardiac event recorder with memory, activator, and programmer.
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.

Provider Requirements, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization Required

Prior authorization is required when requesting an implantable loop recorder (ILR)/implantable cardiac monitor (ICM). Requests must meet the policy’s medical necessity criteria (Sections I–III) or, if applicable, meet alternative review pathways (for example, secondary medical director review for certain indications). Providers should obtain prior authorization before device implantation to avoid claim denials.

Prior authorization required for ILR/ICM requests
Requests must meet policy medical necessity criteria (Sections I–III) or approved secondary review pathways
Providers should confirm plan-specific authorization process and timelines

Documentation Required

Noninvasive Monitoring Prior to ILR

Documented use of appropriate noninvasive ambulatory ECG monitoring is expected prior to consideration of an ILR/ICM unless such monitoring is inconclusive or contraindicated. Appropriate noninvasive monitoring may include continuous short-term monitoring (24 hours up to 7 days) and longer-term external ambulatory monitoring (e.g., 30-day external loop recorder or external event monitor). If symptoms are infrequent (e.g., less than once per month) or external monitoring is contraindicated or inconclusive, an ILR may be appropriate per the policy criteria.

Document prior noninvasive monitoring attempts (e.g., 24–72 hour Holter, 7‑day continuous monitoring, 30‑day external loop recorder) when applicable
If external ambulatory monitoring is inconclusive or contraindicated, note this in documentation

Documentation Required

Required Clinical Documentation

Providers must document the specific clinical indication for the ILR/ICM (for example, cryptogenic stroke with inconclusive or contraindicated 30‑day monitoring; suspected ventricular arrhythmia with inconclusive or contraindicated 30‑day monitoring; structural/infiltrative heart disease with high risk for arrhythmia and inconclusive/contraindicated 30‑day monitoring; recurrent unexplained syncope with suspected arrhythmia and infrequent symptoms). Also document device replacement rationale when applicable (existing device nonfunctional and outside warranty).

Include documentation that criteria I.A–I.D or secondary review criteria II are met, as applicable
For replacements, document device is no longer functioning and is outside warranty

Note

Confirm Plan and Regulatory Authorization Requirements

Confirm any applicable Medicare NCDs, LCDs, and Medicare Coverage Articles and review state Medicaid manual provisions when state rules apply prior to finalizing authorization or performing the procedure. The Health Plan’s posted effective date may differ from plan-specific implementation dates; providers should confirm regulatory or plan-level authorization requirements.

Review applicable Medicare NCDs/LCDs/Medicare Coverage Articles for Medicare members
Follow state Medicaid manual when state provisions apply
Confirm the Health Plan’s effective date and plan-level authorization procedures

Denial Risk

Denial Risk for Not Meeting Criteria

Requests that do not meet the listed medical necessity criteria (e.g., indications I.A–I.D, secondary review criteria II, or replacement criteria III) or lack required documentation (including evidence of prior appropriate noninvasive monitoring when indicated) are at risk for denial. Coverage decisions remain subject to the terms, conditions, exclusions, and limitations of the member’s coverage documents.

Risk of denial if medical necessity criteria not met
Risk of denial if required clinical documentation or prior monitoring evidence is not provided
Coverage subject to member’s plan terms, exclusions, and limitations

Note

Provider Action Reminder

This clinical policy was developed by qualified professionals and is a guide to medical necessity; it does not replace professional judgment. Providers are responsible for verifying and following plan-specific authorization procedures and for ensuring that documentation supports the requested service.

Providers are expected to exercise clinical judgment and follow plan authorization processes
Policy is guidance for medical necessity and not a guarantee of payment

Key Definitions

Implantable Loop Recorder (ILR) / Implantable Cardiac Monitor (ICM) — definition and characteristics

DefinitionA subcutaneous cardiac monitoring device implanted in the left pectoral region that records cardiac rhythm events automatically per programmed criteria or via patient activation; MRI-conditional.

Primary purposeDetection and long-term monitoring of cardiac arrhythmias when symptoms are infrequent or prior noninvasive monitoring is unrevealing.

Event storage and activationStores events automatically according to programmed criteria and can be triggered by the patient using an activator device.

Typical battery longevityBattery life commonly ranges between 2 to 4 years depending on manufacturer and model.

Regulatory status examplesSeveral ILRs have FDA approval (e.g., Reveal LINQ, Reveal XT, Confirm Rx™, BioMonitor).

Inconclusive 30‑day external ambulatory monitoring — prior external monitoring failure

Definition of inconclusive 30-day monitoringA prior 30-day external ambulatory ECG monitoring period (including external loop recorder) that failed to document the arrhythmia or correlate symptoms with a rhythm abnormality.

Context for useUsed when symptoms are infrequent or when longer-term correlation is required and noninvasive monitoring (24-hour to 7-day or 30-day external loop recorder) is unrevealing.

When inconclusive qualifies for ILRSituations where 30-day external ambulatory monitoring is inconclusive or is contraindicated support consideration of ILR per policy indications (e.g., cryptogenic stroke, suspected ventricular arrhythmia, unexplained syncope).

Clinical workflow noteFrequency of symptoms should dictate monitoring strategy; longer-term ECG monitoring is appropriate for infrequent events and ILR is considered after prolonged noninvasive monitoring is unsuccessful.

Guideline and evidence sources — key references supporting ILR/ICM use

AHA/ASA stroke prevention guidelineKleindorfer DO et al., 2021 Guideline for the Prevention of Stroke in Patients with Stroke and Transient Ischemic Attack (AHA/ASA).

ESC atrial fibrillation guidelineHindricks G et al., 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation (ESC/EHRA).

Clinical reviews and practice summariesBisignani A et al., Implantable loop recorder in clinical practice (J Arrhythm, 2018); Vilcant V et al., Implantable Loop Recorder (StatPearls, 2022).

Recent comparative and diagnostic studiesAssaf A et al., 2021 (Open Heart) and Radovanović NN et al., 2021 (Ann Noninvasive Electrocardiol) reporting diagnostic value of ILRs in syncope and heart disease populations.

Clinical Background and Rationale

Background: An implantable loop recorder (also called an implantable cardiac monitor) is a subcutaneous cardiac monitoring device typically implanted in the left pectoral region that records cardiac rhythm events either automatically per programmed criteria or via patient activation. Devices are generally MRI-conditional and have a typical battery longevity of 2–4 years. ILRs are intended for evaluation of infrequent or unexplained symptoms when noninvasive ambulatory monitoring (e.g., Holter, external loop recorders) is unrevealing or contraindicated; they continuously detect and store arrhythmic events and enable remote or in‑person interrogation and analysis.

References, Legal and Administrative Notes

Guidelines and evidence: This policy references major clinical guidelines and peer‑reviewed literature supporting ILR/ICM use, including the AHA/ASA stroke prevention guideline and the ESC atrial fibrillation guideline, as well as contemporary publications on ILR performance in syncope and heart disease. These sources were considered in policy development and are cited for clinical context and evidence review.

Administrative coverage reminder: This clinical policy serves as guidance for medical necessity determinations but does not supersede the member's contract. Providers must verify eligibility, benefits, and any plan-specific prior authorization requirements and should recognize that final coverage is determined by the member's coverage documents and applicable regulatory requirements.