DraftPremera BluecrossPolicy N/A

Mobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Know when Premera Bluecross releases new policies or updates existing guidance.

Defines medical necessity, site-of-service considerations, and documentation and coding expectations for outpatient ambulatory cardiac rhythm monitoring using MCOT and ILRs for detection of intermittent arrhythmias and evaluation of suspected atrial fibrillation or unexplained syncope/presyncope.

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy N/A

Change TypeAdded ILR coverage and coding updates

Effective DateAug 7, 202619d

Last ReviewAug 1, 202613d

Next Review DateN/A

Key ActionDocument at least 14 continuous days of prior non-diagnostic ambulatory cardiac monitoring before requesting ILR or MCOT.

SourceLink

POLICY UPDATE CHANGES

Title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders.

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

Added CPT code 33285, and HCPCS codes C1764, E0616.

Added SOS ASC for implantable loop recorders.

Additional policy criterion added for ILR to require a 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.

Removed the term ambulatory event monitor (AEM) for clarity.

Minor edits to clarify site of service review is only for implantable loop recorders (ILR).

≥14minimum prior monitoring (days)

<=48hMCOT symptom frequency threshold

Related Billing Codes

CPT-93228-REMOTE-CONTINUOUS-ECG-MONITORING-INTERPRETATION

CPT 93228: Remote Continuous ECG Monitoring Interpretation

CPT-93229-WEARABLE-ECG-MONITOR-PLACEMENT-AND-MONITORING

CPT 93229: Wearable ECG Monitor Placement, Instruction, and Transmission Monitoring

HCPCS-C1764-IMPLANTABLE-CARDIAC-EVENT-RECORDER

HCPCS C1764: Implantable Cardiac Event Recorder

HCPCS-E0616-IMPLANTABLE-CARDIAC-EVENT-RECORDER

HCPCS E0616: Implantable Cardiac Event Recorder with Memory, Activator and Programmer

CPT-33285-INSERTABLE-CARDIAC-RHYTHM-MONITOR-INSERTION-PROGRAMMING

CPT 33285: Insertable Cardiac Rhythm Monitor Insertion and Programming

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33285, 93228/29primary CPTs

C1764, E0616primary HCPCS

2016+policy history since

Coverage Criteria

inv-01: ILR Medical Necessity

Use of ILRs (patient-activated or auto-activated) is considered medically necessary when ALL of the following are met:

ILR Criteria: Prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days14 days

See documentation requirements

Symptoms: Recurrent unexplained episodes of presyncope, syncope, palpitations, or dizzinessat least one episode documented

Alternate indication: Evaluation of suspected atrial fibrillation as a cause of cryptogenic stroke with completed negative standard AF workup including 24-hour Holter monitoringnegative standard workup including 24-hour Holter

inv-02: MCOT Medical Necessity

Use of MCOT is considered medically necessary when ALL of the following are met:

MCOT Prior Monitoring: Previous external ambulatory cardiac event monitoring for at least 14 continuous days with a non-diagnostic outcome14 days

Symptom pattern: Symptomatic cardiac arrhythmia occurring less frequently than once every 48 hours (recurrent palpitations, dizziness, presyncope, or syncope)< once every 48 hours

Alternate indication: Evaluation of suspected atrial fibrillation as a cause of cryptogenic stroke (completed negative standard AF workup required)completed negative standard AF workup required

inv-05: Implantable Loop Recorder - Initial Coverage Criteria

Covered when ALL of the following are met for ILR:

ILR coverage prerequisites: Prior ambulatory cardiac monitoring of at least 14 continuous days was non-diagnostic or inconclusive>=14 days

Required prior test before ILR placement

inv-04: Covered Indications

Covered when guideline- or expert-input-supported indications are met

Indications for MCOT or extended monitoring: 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; and Holter monitor and/or external monitoring has been nondiagnostic or contraindicated; and documentation that real-time monitoring is essential for patient safety and will lead to immediate clinical changes (e.g., medication or emergent procedures)all

from 2025 clinical input

Cryptogenic stroke indication: Evaluation of cryptogenic stroke thought to be caused by atrial fibrillation, with nondiagnostic 24–48 hour Holter monitor or 48-hour telemetry; prolonged monitoring (≥1 week or longer) or implantable loop recorder is reasonable to increase AF detection yield>=1 week when prolonged monitoring considered

supported by AHA/ACC/HRS and ISHNE/HRS guidance

Selection by symptom frequency:

inv-03: Not Medically Necessary / Other Indications

Not medically necessary statements

Other uses: MCOT and ILRs are considered not medically necessary when the above criteria are not met or for monitoring asymptomatic individuals (including monitoring for risk factors for arrhythmia, effectiveness of antiarrhythmic medications, or detection of myocardial ischemia by ST-segment changes)

Expanded to explicitly include ILRs and asymptomatic monitoring per policy history

General exclusions: Any indication not meeting the specified prior monitoring and symptom or cryptogenic stroke AF-evaluation criteria is not medically necessary

Requests not meeting required prior monitoring (≥14 days) or clinical indications may be denied

Evidence limitations: Use of newer externally worn devices or implantable memory loop devices is not universally considered medically necessary for all patients due to insufficient evidence of improved clinical outcomes compared with older devices; determinations are case-specific

Clinical input and historical policy statements referenced

Use of ambulatory cardiac monitoring or implantable loop recorders (ILRs) for screening or surveillance of individuals without symptoms is not supported by this policy. Specifically, monitoring asymptomatic individuals for risk factors for arrhythmia, for assessment of the effectiveness of antiarrhythmic medications, or for detection of myocardial ischemia via ST‑segment changes is considered not medically necessary. Documentation submitted for review should demonstrate symptom‑driven indications or completed negative standard workup for cryptogenic stroke when AF evaluation is the goal; routine or screening use in asymptomatic people is excluded from coverage.

Review of clinical input found no universal agreement that continuous remote telemetry (MCOT) provides improved clinical outcomes compared with external event monitors for all patients. While MCOT and newer external monitors may detect arrhythmias comparably, the evidence and expert opinion support restricting MCOT use to selected patients — for example, those with infrequent symptoms (occurring less frequently than once every 48 hours) or where real‑time monitoring is essential for immediate clinical intervention — rather than as a blanket replacement for external event monitoring.

Policy history documents that when this coverage policy was first established, use of mobile cardiac outpatient telemetry (MCOT) was not considered established practice. The original history entry dated 08/09/16 records that "Use of MCOT is considered investigational" at policy inception, which informed earlier coverage determinations and prior denials.

The policy was updated to explicitly exclude monitoring of asymptomatic individuals and placement of ILRs for asymptomatic screening. As reflected in the most recent revisions, the not medically necessary category was expanded to include ILRs and other monitoring strategies when used solely for asymptomatic surveillance, and such requests may be denied if submitted for screening purposes.

Any request for MCOT or ILR that does not meet the policy's specified prerequisites is considered not medically necessary. This includes failure to document the required prior external ambulatory monitoring (a non‑diagnostic trial of at least 14 continuous days where applicable), lack of recurrent symptomatic events (presyncope, syncope, palpitations, dizziness), or absence of a completed standard AF workup when monitoring is sought for cryptogenic stroke evaluation.

Newer externally worn telemetry devices and smaller implantable memory loop recorders have been described in the evidence base and regulatory summaries, but professional reviewers did not reach consensus that these newer devices universally improve clinical outcomes compared with older or established monitors. Consequently, their use should be considered on a case‑by‑case basis and is not automatically considered necessary for all patients.

The policy explicitly states that implantable loop recorders (ILRs) and monitoring for asymptomatic individuals are considered not medically necessary when the coverage criteria are not met. Requests for ILR placement for asymptomatic screening or without documentation of required prior non‑diagnostic ambulatory monitoring of at least 14 continuous days may be denied.

Coding and Billing

ILR insertion CPTCPTCovered

33285

Insertion, subcutaneous cardiac rhythm monitor, including program.

MCOT CPT CodesCPTCovered

93228

External mobile cardiovascular telemetry with electrocardiographic recording, concurrent computerized real-time data analysis and greater than 24 hours of accessible ECG data storage (retrievable with query) with ECG triggered and patient selected events transmitted to a remote attended surveillance center for up to 30 days; 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 greater than 24 hours of accessible ECG data storage (retrievable with query) with ECG triggered and patient selected events transmitted to a remote attended surveillance center for up to 30 days; technical support for connection and patient instructions for use, attended surveillance, analysis and transmission of daily and emergent data reports as prescribed by a physician or other qualified health care professional.

HCPCS CodesHCPCSCovered

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

Added CPT CodesCPTCovered

33285

Insertion, implantable cardiac loop recorder

Added HCPCS CodesHCPCSCovered

C1764	Implantable loop recorder device HCPCS
E0616	External component/supply HCPCS

FDA product codes mentionedmixed

DSH	US Food and Drug Administration product code DSH.
DXH	US Food and Drug Administration product code DXH.
DQK	US Food and Drug Administration product code DQK.
DSI	US Food and Drug Administration product code DSI.
MXD	US Food and Drug Administration product code MXD.
MHX	US Food and Drug Administration product code MHX.

Historical CPT codesCPT

0295T-0298T

CPT codes referenced as removed from the policy (historical).

FDA product codesmixed

DSH	FDA product code (device classification) listed in policy.
DXH	FDA product code (device classification) listed in policy.
DQK	FDA product code (device classification) listed in policy.
DSI	FDA product code (device classification) listed in policy.
MXD	FDA product code (device classification) listed in policy.
MHX	FDA product code (device classification) listed in policy.

Minimum prior external monitoring

Minimum prior external monitoringAt least 14 continuous days of prior non-diagnostic or inconclusive ambulatory cardiac monitoring is required before considering MCOT or ILR.

Evidence sourcePolicy requires documentation that prior external ambulatory cardiac monitoring of not less than 14 continuous days was non-diagnostic or inconclusive.

Applies toBoth mobile cardiac outpatient telemetry (MCOT) and implantable loop recorder (ILR) placement when submitted for evaluation of unexplained syncope, presyncope, palpitations, dizziness, or cryptogenic stroke AF workup.

Symptom frequency for MCOT

Provider Actions and Documentation Requirements

Prior Authorization

Prior Authorization and Coding Notes

Prior authorization may be required for implantable loop recorder (ILR) placement (CPT 33285 and related HCPCS) and for site-of-service determination when ILR implantation is requested. Document clinical rationale if a hospital outpatient department is required instead of an Ambulatory Surgical Center (ASC). Historical coding updates include addition of CPT 33285 and HCPCS codes C1764 and E0616; verify current payer coding rules at time of submission.

Affected codes: CPT 33285; HCPCS C1764, E0616
Site-of-service review applies to ILR implantation (ASC preferred when criteria met)

Denial Risk

Failure to Meet Medical Necessity Criteria

Requests for MCOT or ILR that do not meet the policy's medical necessity criteria (including prior monitoring requirements and documented symptomatic indications) may be denied. Denials can result when documentation is inadequate or when monitoring is requested for asymptomatic surveillance.

Background and Rationale

Implantable loop recorders (ILRs) and mobile cardiac outpatient telemetry (MCOT) provide extended outpatient cardiac rhythm monitoring to detect intermittent arrhythmias such as atrial fibrillation, bradycardia, and tachycardia that may be missed on brief in‑office tests. MCOT offers near‑real‑time telemetry with attended surveillance for up to approximately 30 days, while ILRs are subcutaneously implanted devices that provide long‑term automatic or patient‑activated rhythm surveillance over months to years. Both modalities are used for evaluation of unexplained syncope/presyncope, recurrent palpitations, dizziness, and detection of AF after cryptogenic stroke.

Definitions

Implantable loop recorder (ILR)

DefinitionAn implantable loop recorder (ILR) is a subcutaneously implanted cardiac rhythm monitor that provides long-term automatic or patient-activated surveillance of heart rhythm (months to years).

Primary usesDetection of infrequent or intermittent arrhythmias such as unexplained syncope/presyncope and detection of occult atrial fibrillation after cryptogenic stroke.

Related codingPolicy references CPT 33285 for ILR insertion and HCPCS C1764 and E0616 for device/supplies.

Mobile cardiac outpatient telemetry (MCOT)

DefinitionMobile cardiac outpatient telemetry (MCOT) is an external ambulatory telemetry system that provides continuous ECG data with real-time analysis and transmission to a remote attended surveillance center for up to ~30 days.

Function

Policy Revision History

2016-08-09policy_added

New policy added to Cardiology; use of MCOT was considered investigational at inception; initial effective date planned for 2017.

2016-10-25effective_date_revision

Effective date revised to 2017-03-01.

2017-02-24effective_date_revision

Effective date revised to 2017-03-15.

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy N/A

Change TypeAdded ILR coverage and coding updates

Effective DateAug 7, 202619d

Last ReviewAug 1, 202613d

Next Review DateN/A

Key ActionDocument at least 14 continuous days of prior non-diagnostic ambulatory cardiac monitoring before requesting ILR or MCOT.

SourceLink

On This Page

Select monitoring modality based on frequency and nature of events (e.g., Holter when events anticipated within 48 hours; extended ambulatory ECG 15–30 days for less frequent or uncertain events; implantable monitor for recurrent infrequent unexplained syncope)

per ACC/AHA/HRS and ISHNE/HRS recommendations

Symptom frequency threshold

MCOT is indicated when symptomatic cardiac arrhythmia occurs less frequently than once every 48 hours (i.e., < once every 48 hours).

Examples of qualifying symptomsRecurrent palpitations, dizziness, presyncope, or syncope as documented recurrent episodes.

Relation to prior monitoringIndication requires prior external ambulatory cardiac event monitoring for at least 14 continuous days with a non-diagnostic outcome.

Prior ambulatory monitoring duration

>= 14 days prior monitoringPolicy requires prior ambulatory cardiac monitoring of at least 14 continuous days that is non-diagnostic or inconclusive before ILR placement or consideration of MCOT in many indications.

Documentation requirementMedical records must document the prior non-diagnostic or inconclusive ambulatory cardiac monitoring of at least 14 continuous days.

PurposeEnsures less invasive external monitoring has been attempted and was non-diagnostic prior to implantable or extended telemetry approaches.

Failure to meet documented medical necessity criteria may lead to denial
Ensure prior monitoring and symptomatic indication criteria are met before submission

Note

Historical Denial Rationale

Previous policy history has influenced prior determinations and denials (e.g., MCOT was historically investigational; policy language and coding have changed over time). Review the policy history when responding to retrospective requests or appeals.

08/09/16: New policy; MCOT considered investigational
02/01/24: MCOT criteria updated to be medically necessary in some situations
01/01/26 and 05/01/26: Added ILR criteria and CPT/HCPCS codes; 08/07/26: Added 14-day prior monitoring requirement

Denial Risk

Denial Risk for Asymptomatic Monitoring

Monitoring of asymptomatic individuals and use of ILRs or MCOT solely for asymptomatic surveillance or for purposes such as routine risk-factor screening or assessment of antiarrhythmic effectiveness is not medically necessary and may be denied.

Not medically necessary for asymptomatic monitoring, detection of risk factors only, or assessing antiarrhythmic medication effectiveness

Documentation Required

Required Documentation

Medical records submitted for review must document that medical necessity criteria are met. Include office visit notes with relevant history and physical examination and any prior monitoring reports.

Office visit notes with history & physical
Documented symptomatic episodes (presyncope, syncope, palpitations, dizziness) or evaluation context (e.g., cryptogenic stroke workup)

Documentation Required

Medical Necessity Documentation

Documentation must support the medical necessity for ambulatory cardiac monitoring. For ILR or MCOT requests, include prior non-diagnostic external ambulatory cardiac monitoring of at least 14 continuous days when required, the nature and frequency of symptoms, and why alternative external monitors are inadequate.

For ILR: prior non-diagnostic/inconclusive ambulatory cardiac monitoring >= 14 continuous days
For MCOT: prior external ambulatory cardiac monitoring >= 14 continuous days with non-diagnostic outcome
Indication: recurrent unexplained presyncope/syncope/palpitations/dizziness or evaluation for AF after negative standard workup

Note

Regulatory and Historical Documentation

Provider submissions should reference regulatory and historical coverage context (e.g., CMS national coverage for ambulatory cardiac monitors requires documentation of medical necessity). Historical policy changes and coding updates should be considered during review and appeals.

CMS National Coverage: ambulatory cardiac monitors covered with documentation of medical necessity
Maintain timeline of policy changes for appeals and retrospective reviews

Documentation Required

Prior Monitoring Documentation

Prior ambulatory monitoring of at least 14 continuous days that is non-diagnostic or inconclusive must be documented before ILR or MCOT is approved, unless other criteria in the policy explicitly waive this requirement.

Attach prior monitoring report showing duration (>=14 days) and non-diagnostic result
State dates and type of external monitor used

Note

Modality Selection per Guideline

Select monitoring modality in accordance with guideline-based recommendations: use Holter monitors for frequent events (within 48 hours), extended external monitors (15–30 days) when events are less frequent, MCOT for symptomatic events occurring less than once every 48 hours when prior monitoring is non-diagnostic, and ILR for infrequent unexplained syncope or cryptogenic stroke evaluation per AHA/ACC/HRS and ISHNE/HRS guidance.

Holter: symptomatic events anticipated within 48 hours
Extended external (15–30 days): events not daily or uncertain
MCOT: symptomatic events < once every 48 hours after >=14 days non-diagnostic external monitoring
ILR: infrequent unexplained syncope or extended monitoring for cryptogenic stroke AF detection

Prior Authorization

Required Prior Ambulatory Monitoring

A trial of at least 14 continuous days of ambulatory cardiac monitoring that is non-diagnostic or inconclusive is required before consideration of ILR placement, except where policy lists an explicit exception.

Document duration and non-diagnostic result of prior ambulatory monitoring (>=14 days)
This requirement is added to policy effective 2026-08-07

Streams multilead ECG data, enables real-time/near-real-time detection and transmission of events to a monitoring center, and supports clinician review and reporting.

Typical CPT codesCommonly reported with CPT 93228 and 93229 as described in the policy coding section.

MCOT detailed definition

Detailed definitionMCOT is a multilead, continuous-streaming external monitoring system that can be programmed to autodetect events and autosend them, generate immediate alarms without patient interaction, and transmit near-real-time data to a remote attended surveillance center.

AdvantagesHigher sensitivity and specificity of arrhythmia detection compared with single-lead event recorders; continuous streaming allows immediate alarm generation.

LimitationsLong-term patient acceptance may be reduced due to daily electrode changes; device requires external electrodes and may have signal quality issues similar to other external monitors.

Implantable cardiac monitor

DefinitionAn implantable cardiac monitor (implantable loop recorder) is a subcutaneous device used for long-term monitoring to detect infrequent, unexplained syncope and to detect occult atrial fibrillation after cryptogenic stroke.

Clinical selectionRecommended for recurrent, infrequent, unexplained syncope and reasonable for extended monitoring to improve AF detection after stroke/TIA per guideline statements.

Monitoring durationProvides surveillance over months to years, offering higher AF detection yield than brief Holter or external monitors for infrequent events.

FDA product codes

FDA product codes listedThe policy lists FDA product codes DSH, DXH, DQK, DSI, MXD, and MHX for informational device classification.

PurposeProvided for regulatory identification and informational purposes; not used to establish coverage criteria.

Location in policyRegulatory Status section of the policy lists these FDA product codes.

Guideline references

AHA/ACC/HRS guidance2017 AHA/ACC/HRS guideline statements are cited for cardiac monitoring recommendations and patient selection by frequency and nature of events.

ISHNE-HRS consensus2017 ISHNE-HRS expert consensus on ambulatory ECG and external cardiac monitoring is referenced for monitoring approaches and device selection.

Additional referencesPolicy also cites USPSTF AF screening statement and CMS NCD for electrocardiographic services among other supporting references.

2017-03-15effective_date_revision

Effective date revised to 2017-03-17.

2017-03-17effective_date_revision

Effective date revised to 2017-03-31.

2017-03-23coding_change

Coding update removed CPT codes 0295T–0298T; minor formatting updates.

2017-08-01annual_review

Annual review approved July 11, 2017; no changes to policy statement.

2018-08-01annual_review

Annual review approved July 13, 2018; literature updated through March 2018 and references added; policy statement unchanged.

2019-08-01annual_review

Annual review approved July 25, 2019; literature updated through March 2019 with additional references; policy statements unchanged.

2020-08-01annual_review

Annual review approved July 2, 2020; literature updated through May 2020 and references added; policy statements unchanged.

2021-08-01annual_review

Annual review approved July 9, 2021; literature updated through March 25, 2021; policy statement unchanged.

2022-06-01interim_review

Interim review approved May 9, 2022 with minor edits for clarity; policy intent unchanged.

2022-08-01annual_review

Annual review approved July 11, 2022; literature updated through April 8, 2022; minor edit to policy statement.

2023-08-01annual_review

Annual review approved July 10, 2023; policy updated with literature review through April 11, 2023 and references added.

2025-12-02literature_update

Policy updated through literature review dated 12/02/2025; preparatory to 2026 substantive changes.

2026-08-07material_updateLatest

Title expanded to include Implantable Loop Recorders; ILR added as medically necessary when criteria are met; CPT code 33285 and HCPCS codes C1764 and E0616 added; requirement added for ≥14 days prior non-diagnostic ambulatory monitoring; site-of-service ASC review added for ILR.

For regulatory and historical context, the policy lists FDA product codes used for device classification (for example, DSH, DXH, DQK, DSI, MXD, MHX) for informational purposes. The policy history records multiple review dates and amendments, including the initial 2016 entry stating MCOT was investigational and later updates that added ILR coverage criteria, related CPT/HCPCS coding (e.g., CPT 33285, HCPCS C1764, E0616), site‑of‑service ASC review for ILR, and effective dates for material changes.

Recent history entries summarize changes affecting prior authorization and coding: MCOT was reclassified from investigational to covered with criteria in early 2024; ILR coverage criteria and procedural coding were added in policy updates through 2025–2026. The policy added CPT 33285 and HCPCS codes C1764 and E0616, and implemented site‑of‑service Ambulatory Service Center review for ILR placement. An additional ILR criterion requiring prior non‑diagnostic ambulatory monitoring of at least 14 continuous days became effective Aug 7, 2026, following provider notification.

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Mobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Related Billing Codes

Coverage Criteria

Coding and Billing

Provider Actions and Documentation Requirements

Background and Rationale

Definitions

Policy Revision History