CurrentPremera BluecrossPolicy 2.02.510

Mobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Defines medical necessity criteria for ILR implantation and use of MCOT for outpatient cardiac rhythm monitoring, site-of-service guidance for ILR implantation, documentation requirements, coding references, and evidence summary. This part covers indications, required prior monitoring, exclusions, and related coding/evidence.

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy 2.02.510

Change TypeRevised / Added criteria (ILR added; coding updates)

Effective DateAug 7, 2026

Next Review DateN/A

Key ActionDocument prior >=14-day non-diagnostic ambulatory monitoring and relevant symptoms or cryptogenic stroke workup in office visit notes to support medical necessity for ILR/MCOT.

SourceLink

POLICY UPDATE CHANGES

Policy revised effective Aug. 7, 2026; updated site-of-service and medical necessity criteria for ILR and MCOT.

Title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders; ILRs added as medically necessary when criteria are met.

Additional ILR policy criterion added requiring prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days.

Expanded not medically necessary policy statement to include ILRs and monitoring of asymptomatic individuals.

Minor edits clarifying site of service review applies only to ILRs and does not apply to IHS facilities.

Added implantable loop recorders as medically necessary when criteria are met.

Added criterion requiring prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days before ILR.

Expanded not medically necessary statement to include ILRs and monitoring of asymptomatic individuals.

Title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders.

Minor edits to clarify site of service review is only for ILR and minor clarity edits to ILR criteria.

2Covered technologies (ILR, MCOT)

>=14dRequired prior monitoring duration (ILR)

48hSymptom frequency cutoff for MCOT

1%Potentially emergent events detected (study)

33285,C1764,E0616Added codes (CPT/HCPCS)

Coverage Summary

This policy covers medical necessity criteria for outpatient cardiac rhythm monitoring using Implantable Loop Recorders (ILR) and Mobile Cardiac Outpatient Telemetry (MCOT), and includes site-of-service guidance, documentation and coding requirements. Effective date: Aug. 7, 2026; last review: Jun. 1, 2026.

Key thresholds in the policy include a required prior non-diagnostic or inconclusive ambulatory cardiac monitoring period of >= 14 continuous days before ILR is considered, and MCOT is targeted for individuals with symptoms occurring less frequently than once every 48 hours (i.e., symptom frequency cutoff <48 hours).

High-level covered technologies specified are ILR (implantable memory loop devices with CPT 33285 and HCPCS C1764/E0616 listed) and MCOT (external mobile telemetry with CPT 93228/93229); the scope is limited to these device classes.

Quick Thresholds

Prior ambulatory monitoring duration (ILR)>= 14 continuous days

Prior ambulatory monitoring duration (MCOT prerequisite)>= 14 continuous days (external ambulatory cardiac event monitoring non-diagnostic)

Symptom frequency threshold for MCOTSymptoms occurring less frequently than once every 48 hours

Holter/telemetry requirement for cryptogenic stroke workupNegative 24- to 48-hour Holter monitor (and/or 48-hour telemetry) prior to further extended monitoring/ILR

MELD score site-of-service threshold> 8 (advanced liver disease may justify hospital outpatient site)

COPD / Asthma FEV1 site-of-service thresholdsCOPD: FEV1 < 50%; Poorly controlled asthma: FEV1 < 80% despite treatment

Implantable Loop Recorder (ILR) — Medically Necessary

ILR (implantable loop recorder) - Medically Necessary

Covered when ALL of the following are met:

ALL of the following

AND one of
- Prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days>= 14 continuous days
  Added to ILR criteria effective Aug. 7, 2026
- Recurrent unexplained episodes of presyncope, syncope, palpitations, or dizziness
- Evaluation of suspected atrial fibrillation (AF) as a cause of cryptogenic stroke with completed negative standard workup for AF including 24-hour Holter monitoring

Mobile Cardiac Outpatient Telemetry (MCOT) — Medically Necessary

MCOT (mobile cardiac outpatient telemetry) - Medically Necessary

Covered when ALL of the following are met:

ALL of the following

Previous external ambulatory cardiac event monitoring of at least 14 continuous days with a non-diagnostic outcome>= 14 continuous days
AND one of
- Individual has symptoms of cardiac arrhythmia (recurrent palpitations, dizziness, presyncope, or syncope) occurring less frequently than once every 48 hours< = symptoms less frequent than once every 48 hours
- Evaluation of suspected atrial fibrillation as a cause of cryptogenic stroke

Not Medically Necessary / Expanded Exclusions

ILR/MCOT - Not Medically Necessary

Not covered when any of the following apply:

Monitoring asymptomatic individuals for risk factors for arrhythmia

Expanded not medically necessary statement

Monitoring for effectiveness of antiarrhythmic medications

Detection of myocardial ischemia by detecting ST-segment changes

Any other indications not specified as medically necessary

Not Medically Necessary — Expansion

Policy expansions clarifying not medically necessary uses:

Site of Service Criteria and Clinical Risk Factors

Site of Service Criteria for ILR Implantation

Site of service considered medically necessary when ONE of the following applies:

Ambulatory surgical center (preferred) when appropriate

Preferred site for elective ILR when criteria met

Off campus-outpatient hospital/medical center if no qualifying ASC within 30 miles that can provide necessary care (no geographically accessible ASC with necessary equipment, or ASC where physician has privileges, or ASC guideline prohibits use related to individual's health/weight)30 miles

On campus-outpatient hospital/medical center when no access to ASC per above; or individual aged 18 or younger; or service performed with additional service requiring hospital outpatient department; or individual has clinical condition increasing risk for complications

Clinical risk conditions listed separately

Indications and Operational Criteria

Medically Necessary Indications (MCOT / Mobile Cardiac Telemetry and ILR)

Covered when ALL of the following are met:

Evaluation of recurrent unexplained clinically significant presyncope, syncope, severe palpitations or dizziness when symptoms are thought to be due to a cardiac arrhythmia as the most likely diagnosis

Symptoms thought to be due to arrhythmia required

Prior non-diagnostic monitoring: Holter monitor and/or external ambulatory event monitor (AEM) has been nondiagnostic or contraindicated; for ILR specifically: prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days>= 14 continuous days for ILR

Added to ILR criteria effective Aug. 7, 2026

Documentation that real-time monitoring is essential for patient safety and will lead to immediate clinical changes such as medication or other emergent procedures

Coding

ILR Procedure CPTCPTCovered

33285

Insertion, subcutaneous cardiac rhythm monitor, including program.

MCOT Monitoring CPTCPTCovered

93228	External mobile cardiovascular telemetry with electrocardiographic recording, concurrent computerized real-time data analysis and >24 hours of accessible ECG data storage; review and interpretation with report by a physician or other qualified health care professional.
93229	External mobile cardiovascular telemetry with electrocardiographic recording, concurrent computerized real-time data analysis and >24 hours of accessible ECG data storage; technical support for connection and patient instructions for use, attended surveillance, analysis and transmission of daily and emergent data reports.

HCPCS Device CodesHCPCSCovered

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

Added CPT / HCPCS codesmixed

33285	CPT code added for implantable loop recorder.
C1764	HCPCS code added to policy for implantable device.
E0616	HCPCS code added to policy for implantable device and programmer.

Added CPT code for ILRCPT

33285

CPT code added to policy for implantable loop recorder (historical note).

Added HCPCS codesHCPCS

C1764	HCPCS added to policy (code listed in history).
E0616	HCPCS added to policy (code listed in history).

Removed CPT codes (historical)CPT

0295T	Removed from policy (coding update noted 03/23/17).
0296T	Removed from policy (coding update noted 03/23/17).
0297T	Removed from policy (coding update noted 03/23/17).
0298T	Removed from policy (coding update noted 03/23/17).

Site of Servicemixed

SOS ASC

Ambulatory surgical center (preferred) site-of-service for ILR implantation; policy includes criteria for when hospital outpatient settings are acceptable or not; site-of-service review does not apply to IHS facilities.

Provider Actions & Billing Impact

Prior Authorization

Prior authorization and site-of-service review for ILR

Prior authorization and site-of-service review is required for elective ILR implantation. Verify prior authorization before scheduling the procedure. Site-of-service review applies to determine the most appropriate outpatient location (ASC preferred); note that site-of-service review does not apply to Indian Health Service (IHS) facilities.

Affected codes: 33285, C1764, E0616
Site-of-service review does NOT apply to IHS facilities

Documentation Required

Medical record documentation required

Medical record documentation must demonstrate that all policy medical necessity criteria are met, including symptom history, prior monitoring, and workup when relevant. Documentation should support that monitoring is likely to change management.

Background, Evidence & Definitions

Background: ILRs and MCOT provide extended outpatient cardiac monitoring to detect intermittent arrhythmias not captured by brief in-office tests. ILRs offer long-term, automatic rhythm surveillance (months to years) while MCOT provides continuous real-time transmission and analysis for up to ~30 days.

This policy focuses specifically on when each technology (ILR versus MCOT) is medically necessary versus not, and limits its scope to those two device classes rather than the broader array of ambulatory monitors.

Evidence / Source	Summary
RCTs/Observational evidence for ILR	Studies report higher arrhythmia detection with ILR versus shorter-term monitoring; evidence sufficient to show improvement in diagnostic yield and net health outcome when prolonged monitoring is needed.
RCTs for MCOT	One RCT (Rothman 2007) compared MCOT with standard loop event monitoring, showing higher detection rates for MCOT but unclear impact on clinical outcomes.
Large observational MCOT detection rates	Large retrospective and cohort studies report higher diagnostic yield for MCOT (e.g., Favilla 2015: 14% AF detection after cryptogenic stroke; Kadish 2010: ~1% potentially emergent events during monitoring); observational data show increased arrhythmia detection but limited outcome data.
Guideline recommendation	ACC/AHA/HRS and other societies state that external cardiac monitoring approaches including MCOT can be useful for selected patients with syncope (Class IIa) and that ILR may be reasonable for extended monitoring after cryptogenic stroke.
AAN recommendation / Stroke guidance	AAN: clinicians might obtain outpatient cardiac rhythm studies in cryptogenic stroke and prolonged monitoring (≥1 week) may increase yield (Level C).
Literature review date	Literature review and policy updated through August 29, 2025 and December 2, 2025 with subsequent policy revisions effective April 8, 2026 and August 7, 2026.

Term	Definition
MCOT	Mobile cardiac outpatient telemetry: continuously recording or autotriggered memory loop devices that transmit data to a central recording station with real-time monitoring and analysis.
ILR	Implantable loop recorder: implantable memory loop device providing long-term automatic rhythm surveillance, patient- or auto-activated; subcutaneous implantable cardiac monitor for extended rhythm surveillance.
Non-diagnostic ambulatory cardiac monitoring	Prior external ambulatory cardiac monitoring (e.g., event monitor) of at least 14 continuous days that did not establish a diagnosis.
AEM	Ambulatory Event Monitor — term removed from policy for clarity (AEM removed from policy).
Mobile Cardiac Telemetry	External real-time ambulatory cardiac monitoring with streaming and immediate alarm generation (synonymous with MCOT in this policy).

Medicare Determinations

Effective	Name	Number	Type
2004	Electrocardiographic Services	20.15	NCD

Revision History

2026-08-07policy_revision/effectiveLatest

Policy revised effective Aug. 7, 2026; header indicates revision and effective date; updated site-of-service and medical necessity criteria for ILR and MCOT.

2026-08-07criteria_addedLatest

Added requirement that ILR placement requires prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days before ILR is considered medically necessary.

2026-08-07

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy 2.02.510

Change TypeRevised / Added criteria (ILR added; coding updates)

Effective DateAug 7, 2026

Next Review DateN/A

Key ActionDocument prior >=14-day non-diagnostic ambulatory monitoring and relevant symptoms or cryptogenic stroke workup in office visit notes to support medical necessity for ILR/MCOT.

SourceLink

On This Page

24-hour Holter negative

Implantable Loop Recorder (ILR) — Medically Necessary Criteria (summary of added criteria)

Concise summary emphasizing added prior monitoring requirement for ILR:

ILR placement meets clinical indications per policy AND prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days has been performed>= 14 continuous days

Summarizes added ILR criterion effective Aug. 7, 2026

Mobile Cardiac Outpatient Telemetry (MCOT) / Mobile Cardiac Telemetry — Policy change summary

Policy change affirmation:

MCOT is considered medically necessary when the policy clinical criteria are met (detailed criteria in policy) and real-time monitoring is essential to patient safety or management

Short affirmation of coverage when detailed criteria satisfied

Monitoring of asymptomatic individuals

Explicitly included in expanded not medically necessary statement effective Aug. 7, 2026

Use of ILRs when ILR criteria are not met (including without required prior >=14 day non-diagnostic ambulatory monitoring)>= 14 continuous days required for ILR

ILRs added to expanded not medically necessary expansion

Claims for monitoring asymptomatic individuals are listed as expanded not medically necessary and may be denied.

Similarly, ILR placement without documentation that a prior non-diagnostic or inconclusive ambulatory cardiac monitoring period of at least 14 continuous days has been performed may be considered not medically necessary and subject to denial per provider guidance requiring evidence of prior monitoring.

Sites considered not medically necessary for elective ILR when criteria not met: Off campus-outpatient hospital/medical center or On campus-outpatient hospital/medical center when site criteria not met; Inpatient hospital/medical center for elective ILR

Inpatient elective ILR not medically necessary

Clinical conditions increasing risk (affecting site of service decision)

Any one of the following may justify hospital outpatient setting (clinical conditions increasing risk):

Anesthesia Risk: ASA classification III or higher; personal history of complication of anesthesia; documentation of alcohol dependence or history of cocaine use; prolonged surgery (>3 hours)

Cardiovascular Risk: Uncompensated chronic heart failure (NYHA class III/IV); recent MI (<3 months); poorly controlled/resistant hypertension; recent cerebrovascular accident (<3 months); increased risk for cardiac ischemia (DES <1 year or angioplasty <90 days); symptomatic cardiac arrhythmia despite medication; significant valvular heart disease

Liver Risk: Advanced liver disease (MELD Score greater than 8)MELD > 8

Pulmonary Risk: COPD (FEV1 <50%); poorly controlled asthma (FEV1 <80% despite treatment); moderate to severe obstructive sleep apnea (OSA)COPD FEV1 <50%; Asthma FEV1 <80%

Site-of-Service Risk Thresholds

MELD Score> 8

COPD (FEV1)FEV1 < 50%

Asthma (FEV1 despite treatment)FEV1 < 80%

Applies to MCOT scenarios where immediate management changes expected

Medically Necessary Indication - Cryptogenic Stroke

Covered when ALL of the following are met:

Evaluation of cryptogenic stroke thought to be caused by atrial fibrillation

Prior non-diagnostic short-term monitoring: Nondiagnostic 24- to 48-hour Holter monitor OR nondiagnostic 48-hour telemetry prior to extended monitoring/ILR24-48 hour Holter or 48-hour telemetry nondiagnostic

Required before ILR in cryptogenic stroke AF evaluation

Include office visit notes with relevant history and physical
Document symptom type and frequency (presyncope, syncope, palpitations, dizziness)
For cryptogenic stroke AF evaluation, document a negative standard workup for AF including 24-hour Holter monitoring

Billing Rule

Use specified CPT/HCPCS codes

Use the specified CPT and HCPCS codes when billing for ILR insertion and MCOT services. Report ILR insertion with the appropriate CPT/HCPCS and report MCOT monitoring using the external mobile telemetry CPTs.

CPT/HCPCS codes to use: 33285, 93228, 93229, C1764, E0616
Report ILR insertion with 33285 or HCPCS C1764/E0616 as applicable
Report MCOT services with 93228 and 93229 per technical and professional components

Note

Site of service selection for ILR implantation

Select the most appropriate outpatient site of service for elective ILR implantation. An ambulatory surgical center (ASC) is the preferred site when available and clinically appropriate. Hospital outpatient departments (on-campus or off-campus) may be used only when ASC access is not available or the patient meets listed clinical exceptions. Inpatient elective ILR implantation is considered not medically necessary.

Preferred site: Ambulatory Surgical Center (ASC)
Hospital outpatient (on-campus or off-campus) allowed only if no ASC within 30 miles with necessary capability/privileges, the patient is ≤18 years, procedure is combined with another requiring hospital setting, or patient has documented increased risk for complications
Inpatient elective ILR implantation is not medically necessary

Denial Risk

Denial risk for asymptomatic monitoring

Claims for monitoring that lack documented symptoms or other indications consistent with policy (i.e., asymptomatic surveillance or routine risk-factor screening) may be denied. Ensure the medical record demonstrates symptomatic complaints or evaluation for cryptogenic stroke as specified.

Denial risk for claims submitted for asymptomatic monitoring, screening, or routine surveillance
Ensure documentation shows symptoms or cryptogenic stroke AF evaluation with prior 24-hour Holter as required

Documentation Required

Document prior nondiagnostic monitoring

Document prior nondiagnostic external ambulatory cardiac monitoring before ILR implantation. The record must show at least 14 continuous days of prior non-diagnostic or inconclusive ambulatory monitoring for ILR candidates and that real-time or prolonged monitoring would likely change management.

Prior nondiagnostic external monitoring >= 14 continuous days is required before ILR implantation
For MCOT, prior external ambulatory monitoring of at least 14 continuous days with a non-diagnostic outcome is required
Documentation should state that further monitoring (ILR or MCOT) will meaningfully affect diagnosis or management

Expanded not medically necessary policy statement to explicitly include ILRs and monitoring of asymptomatic individuals.

2026-04-08title_and_code_changes/effective

Effective April 8, 2026 (90-day provider notice): Title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders; ILRs added as medically necessary when criteria are met; CPT 33285 and HCPCS C1764, E0616 added; SOS ASC added for ILR site-of-service.

2026-05-01administrative_clarification

Administrative clarification May 1, 2026: minor edits clarifying site-of-service review applies only to ILRs and does not apply to Indian Health Services (IHS) facilities; removed term Ambulatory Event Monitor (AEM) for clarity.

2026-04-14minor_edits

Minor ILR criteria edits April 14, 2026 to improve clarity (administrative/language changes).

Historicalcoding_update/history

Coding updates included addition of CPT 33285 and HCPCS codes C1764 and E0616 for ILR and HCPCS device codes listed in coding section.