ModifiedPremera BluecrossPolicy 2.02.510

Mobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Defines medical necessity criteria, documentation requirements, site-of-service considerations, and coding for MCOT and implantable loop recorder (ILR) implantation for outpatient cardiac rhythm monitoring. Focus is limited to MCOT and ILRs (not other ambulatory monitors).

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy 2.02.510

Change TypeRevised / Added ILR and MCOT criteriacoding updates

Effective DateMay 1, 2026

Next Review Date

Key ActionProviders must document prior external ambulatory monitoring (duration and result) and that symptoms are infrequent (for ILR) or that ≥14 days of external monitoring was non-diagnostic (for MCOT), including symptom types (palpitations, dizziness, presyncope, syncope).

SourceLink

POLICY UPDATE CHANGES

Policy has been revised with an effective date of May 1, 2026 (noted as revised).

Title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders and implantable loop recorders added as medically necessary when criteria are met.

Added policy criteria for which MCOT is now considered medically necessary rather than investigational (02/01/24 history entry).

Minor edits to ILR criteria for greater clarity and header added to indicate site of service review does not apply to IHS facilities (05/01/26 and 06/01/26 updates).

Removed CPT codes 0295T-0298T from coding list (03/23/17).

2Primary technologies covered (ILR, MCOT)

14 daysRequired prior external monitoring for MCOT

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30 milesASC distance threshold for site-of-service consideration

1%Proportion of MCOT events considered potentially emergent in cited study

6Device types discussed

3New codes added in 2026 (CPT/HCPCS)

Coverage Summary

Policy Number: 2.02.510. Effective Date: May 1, 2026. Scope: Defines medical necessity criteria, documentation requirements, site-of-service considerations, and coding for Mobile Cardiac Outpatient Telemetry (MCOT) and Implantable Loop Recorders (ILR) for outpatient cardiac rhythm monitoring. Focus is limited to MCOT and ILRs (not other ambulatory monitors). The policy includes criteria for when MCOT and ILR are medically necessary, required documentation for prior external monitoring, site-of-service review for elective ILR implantation, and specific CPT/HCPCS codes to report.

Quick facts and key thresholds

Required prior external monitoring for MCOT>= 14 continuous days

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

ASC distance threshold (site-of-service)No qualifying ASC within 30 miles

New codes added in 20263 (CPT 33285, HCPCS C1764, E0616)

Proportion of MCOT emergent events (study)~1% of MCOT-detected events potentially emergent (Kadish et al)

Medical-Necessity Criteria

Implantable Loop Recorders (ILR) - Medically Necessary

The use of either patient‑activated or auto‑activated implantable loop recorders (ILRs) may be considered medically necessary when ALL of the following criteria are met:

ALL of the following

Individual experiences recurrent, infrequent symptoms such as palpitations, dizziness, presyncope, or syncope
Symptoms should be documented in office visit notes
Previous external ambulatory cardiac event monitoring was unsuccessful (non‑diagnostic)
See Documentation Requirements for acceptable prior external monitoring and required documentation
ILR is being used for long‑term monitoring for atrial fibrillation (AF) or possible AF
Includes evaluation of suspected AF as a cause of cryptogenic stroke or for surveillance after AF ablation

Device selection guidance and indications

Background: ILRs provide long-term implanted automatic rhythm surveillance over months to years, whereas MCOT provides continuously recording or autotriggered external telemetry with real-time transmission to remote monitoring centers. Both enable extended outpatient monitoring to detect intermittent arrhythmias not captured on brief in-office testing. The policy aligns coverage with evidence that prolonged monitoring improves arrhythmia detection and reflects a rationale of progressive diagnostic escalation from external monitoring to ILR when symptoms are infrequent or extended surveillance is required.

General device selection guidance / indications

Choice of monitor based on frequency and nature of symptoms; ambulatory monitoring useful when evaluating suspected arrhythmic etiology for palpitations, presyncope, syncope, ventricular arrhythmia, or to detect AF after stroke/TIA.

Choice of specific cardiac monitor should be determined on the basis of frequency and nature of syncope events.

Guideline- and evidence-based summary: ACC/AHA/HRS guidance recommends selecting monitoring modality based on symptom frequency and nature and notes implantable cardiac monitors can be useful for evaluation of selected patients with suspected arrhythmic syncope; for patients with stroke or TIA of undetermined cause, initial and, if needed, extended monitoring with an implantable loop recorder are reasonable to improve AF detection. ISHNE–HRS consensus supports extended ambulatory ECG (15–30 days) when events are not daily and endorses monitoring approaches including MCOT and ILR for cryptogenic stroke. The USPSTF (2022) concluded evidence is insufficient to recommend screening for AF in asymptomatic adults ≥50 years (Grade I). Medicare NCD (20.15, 2004) covers ambulatory cardiac monitors when medical necessity is documented, including detection of symptomatic transient arrhythmias and to guide antiarrhythmic therapy.

Coding

ILR CPT/HCPCS codesCPT|HCPCSCovered

33285	Insertion, subcutaneous cardiac rhythm monitor, including program
C1764	Event recorder, cardiac (implantable) (HCPCS)
E0616	Implantable cardiac event recorder with memory, activator, and programmer (HCPCS)

MCOT CPT codesCPTCovered

93228	External mobile cardiovascular telemetry with ECG recording, concurrent computerized real-time analysis, >24 hrs data storage, transmission to remote attended surveillance center up to 30 days; review and interpretation with report
93229	External mobile cardiovascular telemetry with ECG recording, concurrent computerized real time data analysis and >24 hrs data storage; technical support, attended surveillance, analysis and transmission of daily and emergent data reports

Added / referenced procedure and supply codesmixed

33285	CPT code added for implantable loop recorder (per history entry)
C1764	HCPCS code added (listed in history for ILR)
E0616	HCPCS code added (listed in history)

Removed CPT codes (historical)CPT

0295T	Removed (coding update noted in history)
0296T	Removed (coding update noted in history)
0297T	Removed (coding update noted in history)
0298T	Removed (coding update noted in history)

Coding updates and provider actions: Policy history documents coding revisions effective April 8, 2026 and May 1, 2026, with addition of CPT 33285 and HCPCS C1764, E0616, and prior removal of CPT 0295T–0298T in earlier history. Providers should report current CPT/HCPCS codes per the policy history and billing rules and follow the policy's documentation and site-of-service prior‑authorization requirements when applicable.

Provider Actions / Authorization & Documentation

Documentation Required

Document prior monitoring and symptoms

Providers must document prior external ambulatory monitoring (duration and result) and that symptoms are infrequent (for ILR) or that ≥14 days of external monitoring was non-diagnostic (for MCOT). Required documentation for ILR: prior external monitoring duration and that it was unsuccessful; description of infrequent recurrent symptoms including at least one of: palpitations, dizziness, presyncope, syncope.

Prior external ambulatory monitoring: duration and result (e.g., unsuccessful/non-diagnostic)
Symptom types to document: palpitations, dizziness, presyncope, syncope
For MCOT: documentation that at least 14 continuous days of prior external monitoring was non-diagnostic

Prior Authorization

Medical necessity review for ILR implantation

ILR implantation is subject to medical necessity review. Include ICD/CPT/HCPCS codes for the procedure and device when requesting review. Site-of-service considerations may apply (ASC addition noted; see SOS criteria); the site-of-service review does not apply to IHS facilities. ASC additions or other site-of-service documentation (e.g., lack of accessible ASC or clinical risk factors) may be required for elective ILR implantation.

Definitions & Evidence Highlights

Definitions / glossary: 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: an implantable memory loop device for long-term automatic rhythm surveillance. ASC — Ambulatory Surgical Center: an outpatient facility considered the preferred site of service for certain elective procedures when criteria are met. MELD — Model for End-Stage Liver Disease score, used to define advanced liver disease risk (policy uses threshold MELD > 8). ASA classification III — American Society of Anesthesiologists physical status III, indicating severe systemic disease that increases anesthesia risk.

Study / Source	Key finding
Rothman et al. (2007) RCT	MCOT detected more clinically significant arrhythmias than standard loop/event monitoring; median time to diagnosis 7 days (MCOT) vs 9 days (loop). Detection difference driven by asymptomatic rapid AF/flutter and ventricular tachycardia.
Derkac et al. (2017) observational	Retrospective review: MCOT (mean ~20 days) had significantly higher diagnostic yield vs autotrigger looping recorder (e.g., +128% for AF, +222% for VT); mean time to diagnosis shorter with MCOT.
Favilla et al. (2015) cohort	In 227 patients with cryptogenic stroke monitored 28 days with MCOT, AF detected in 14%; 84% of those diagnosed were started on anticoagulation.
Kadish et al. (2010) large registry	Among 26,438 MCOT users (mean ~21 days), 21% had an arrhythmic event requiring physician notification; ~1% (260 individuals) had potentially emergent events (eg, wide-complex tachycardia, long pauses, severe bradycardia).
Guidelines (ACC/AHA/HRS, ISHNE‑HRS)	Recommend selecting monitor by symptom frequency; MCOT and ILR are useful options — ILR reasonable for recurrent infrequent syncope and for extended AF detection after stroke/TIA.
Policy summary / coverage notes	Plan considers MCOT medically necessary when criteria met (≥14 days prior non‑diagnostic external monitoring and symptoms infrequent or evaluation for cryptogenic stroke); ILR medically necessary when prior external monitoring unsuccessful or long‑term AF monitoring required.

Medicare Determinations

Effective Year	Name / Number	Summary
2004	Medicare NCD 20.15 (Electrocardiographic Services)	Ambulatory cardiac monitors are covered when documentation of medical necessity exists; indications include detection of symptomatic transient arrhythmias and determination of arrhythmic drug therapy (to initiate, revise, or discontinue therapy).
2004 (referenced in policy)	CMS NCD reference (20.15) — policy incorporation	Policy cites Medicare NCD 20.15 as support: ambulatory monitors (including external and implantable loop recorders) are covered if medical necessity documented; this NCD underpins documentation and indication requirements in the policy criteria (eg, prior monitoring, symptom documentation).

Revision History

2017-03-23coding_removed

Coding cleanup: removed CPT codes 0295T-0298T from coding list.

2024-01-09interim_review

Interim review approved January 9, 2024 added MCOT criteria; MCOT considered medically necessary when specified criteria (including ≥14 days prior external monitoring) are met.

2026-04-08policy_additions

Effective April 8, 2026 (following 90-day provider notification): title changed to Mobile Cardiac Telemetry and Implantable Loop Recorders; added implantable loop recorders as medically necessary when criteria met; added CPT 33285 and HCPCS C1764, E0616; added site-of-service (SOS) ASC for ILR and related policy reference 11.01.525.

Operational thresholds & risk criteria

Discrete policy thresholds and drivers

External ambulatory monitoring prior to MCOT>= 14 continuous days (non-diagnostic required)

MCOT symptom frequency requirementSymptoms occurring less frequently than once every 48 hours (drives MCOT coverage)

ASC distance threshold for ILR site-of-serviceNo qualifying ASC within 30 miles (affects ASC vs hospital outpatient decision)

MELD score threshold (liver risk)> 8 (clinical condition that may justify hospital site-of-service)

Pulmonary thresholds (drive site-of-service decisions)COPD: FEV1 < 50%; Asthma: FEV1 < 80% despite treatment

Which thresholds drive decisionsPrior external monitoring duration and symptom frequency drive MCOT coverage; ASC distance and clinical risk thresholds (MELD, COPD/ASTHMA FEV1) drive site-of-service determinations for ILR

Policy Summary

PayerPremera Bluecross

PolicyMobile Cardiac Outpatient Telemetry and Implantable Loop Recorders

Policy CodePolicy 2.02.510

Change TypeRevised / Added ILR and MCOT criteriacoding updates

Effective DateMay 1, 2026

Next Review Date

SourceLink

On This Page

ILR - Long-term monitoring for AF

Long‑term monitoring with an ILR may be considered medically necessary for detection of atrial fibrillation when ALL of the following are met:

ALL of the following

Long‑term monitoring is required for evaluation of suspected or possible atrial fibrillation (AF)
Standard, shorter‑term external monitoring (e.g., 24‑ to 48‑hour Holter) was non‑diagnostic or is not expected to capture the infrequent events of concern
Clinical rationale for preferring ILR over external monitor should be documented

Mobile Cardiac Outpatient Telemetry (MCOT) - Medically Necessary

Mobile cardiac outpatient telemetry (MCOT) is considered medically necessary when ALL of the following are met:

ALL of the following

An external ambulatory cardiac event monitoring of at least 14 continuous days was non‑diagnostic
Documentation must include prior monitoring start/end dates and report demonstrating non‑diagnostic results
AND one of the following:
- The individual has symptoms of cardiac arrhythmia (recurrent palpitations, dizziness, presyncope, or syncope) occurring less frequently than once every 48 hours
  Document frequency and character of episodes in office notes
- Evaluation of suspected atrial fibrillation as a cause of cryptogenic stroke
  Applicable when standard workup including 24‑hour Holter monitoring has been negative

MCOT - Not Medically Necessary

MCOT is considered not medically necessary when the criteria for medical necessity above are not met.

ALL of the following

Indication does not meet the prior 14‑day non‑diagnostic external monitoring requirement or symptom/foundational criteria
Used for any other indications not listed as medically necessary in this policy

Site of Service - ILR implantation

Site‑of‑service decisions for ILR implantation: the procedure may be performed in the most appropriate, safe, and cost‑effective setting. ILR implantation is considered medically necessary in the ambulatory surgical center (ASC) or outpatient hospital/medical center when ANY of the following apply:

ANY of the following

No qualifying ASC within 30 miles that can provide necessary care due to lack of equipment or access to physician privileges
Individual is aged 18 years or younger
Procedure is being performed in conjunction with an additional service that requires a hospital outpatient department and both are performed in the same operative session
Individual has a clinical condition that increases risk for complications (examples include but are not limited to anesthesia risk such as ASA class III or higher; uncompensated chronic heart failure NYHA class III–IV; recent MI or cerebrovascular accident within 3 months; poorly controlled, resistant hypertension; significant valvular disease; advanced liver disease; severe pulmonary disease; symptomatic cardiac arrhythmia despite medication)
This list is illustrative, not exhaustive; document clinical details supporting higher risk

Not medically necessary sites:

Inpatient hospital setting for elective ILR implantation when site‑of‑service criteria above are not met

Documentation Requirements

Documentation Requirements: the patient’s medical record must support that medical necessity criteria are met for ILR or MCOT.

ALL of the following

Office visit notes documenting relevant history and physical exam
For ILR: documentation that previous external ambulatory cardiac event monitoring was unsuccessful (non‑diagnostic) AND records of infrequent recurrent symptoms (palpitations, dizziness, presyncope, or syncope)
Include prior monitor type, dates, and results
For ILR: documentation of requirement for long‑term monitoring for AF or possible AF when applicable
For MCOT: documentation that prior external ambulatory cardiac event monitoring of at least 14 continuous days was non‑diagnostic
Provide start/end dates and report showing non‑diagnostic findings
For MCOT: documentation of symptomatic cardiac arrhythmia occurring less frequently than once every 48 hours (palpitations, dizziness, presyncope, syncope) OR evaluation for suspected AF as a cause of cryptogenic stroke
All submitted records must include sufficient clinical detail to demonstrate why shorter‑term monitors were inadequate and justify the chosen monitoring modality

Relevant codes to include with request: 33285, C1764, E0616
Document site-of-service rationale when applicable (ASC availability, physician privileges, distance, or clinical risk factors)
Note: Site-of-service review does not apply to Indian Health Services (IHS) facilities

Prior Authorization

MCOT medical necessity

MCOT medical necessity requires documentation that prior external ambulatory cardiac event monitoring of at least 14 continuous days was non-diagnostic, plus that the individual's symptoms occur less frequently than once every 48 hours (e.g., palpitations, dizziness, presyncope, syncope) or that MCOT is being used for evaluation of suspected atrial fibrillation as a cause of cryptogenic stroke. Report MCOT services with CPT codes 93228 and 93229 as applicable.

Required prior monitoring: ≥14 continuous days of external ambulatory monitoring documented as non-diagnostic
Symptom frequency requirement: symptoms occurring less frequently than once every 48 hours
Alternative qualifying indication: evaluation for suspected AF as cause of cryptogenic stroke
MCOT CPT codes: 93228, 93229

Billing Rule

Use of specific CPT/HCPCS codes

Report the CPT/HCPCS codes that correspond to services actually performed. For external mobile telemetry services report CPT codes 93228 or 93229. For implantable loop recorder insertion/reporting use CPT 33285 or the applicable HCPCS device codes (C1764, E0616). When both monitoring and implantation services are performed, report the applicable codes for each service as appropriate.

External mobile telemetry: CPT 93228, CPT 93229
ILR insertion: CPT 33285
ILR device/supply HCPCS: C1764, E0616
Report each applicable code for the specific service(s) rendered

Prior Authorization

Site of service review for implantable loop recorders

Site-of-service review applies to elective ILR implantation. When submitting for prior authorization include codes for the procedure/device (33285, C1764, E0616) and documentation supporting the selected site of service (ASC vs hospital outpatient). ASC addition is noted in policy history; the SOS criteria include a 30-mile ASC distance threshold and other access/clinical risk factors. The SOS requirement does not apply to IHS facilities.

Codes to reference: 33285, C1764, E0616
ASC distance/access threshold: no qualifying ASC within 30 miles may justify hospital outpatient site
Document reasons for hospital outpatient vs ASC (no ASC equipment, lack of physician privileges at ASC, ASC guideline prohibitions, age ≤18, concurrent procedures, or clinical risk factors)
Note: Site-of-service review does not apply to Indian Health Services (IHS) facilities

Documentation Required

Medical necessity documentation

Medical necessity documentation should reference CMS National Coverage Determination for electrocardiographic services and demonstrate the indication for ambulatory cardiac monitoring. Acceptable purposes include detection of symptomatic transient arrhythmias and determination of arrhythmic drug therapy (to initiate, revise, or discontinue therapy). Include office visit notes, prior monitoring results, and symptom documentation to support medical necessity.

Reference: CMS NCD for Electrocardiographic Services (covers ambulatory cardiac monitors when medical necessity documented)
Purposes to document: detection of symptomatic transient arrhythmias; determination/initiation/revision/discontinuation of arrhythmic drug therapy
Include office visit notes, prior monitoring reports, and symptom descriptions

Billing Rule

Coding updates

Coding updates: the policy history added CPT code 33285 and HCPCS codes C1764 and E0616; CPT codes 0295T–0298T were removed historically. Providers should use the current CPT/HCPCS codes listed in the policy when reporting services.

Codes added: 33285, C1764, E0616
Codes removed (historical): 0295T, 0296T, 0297T, 0298T
Advisory: report services using the current CPT/HCPCS codes as updated in policy history

2026-05-01effective_revisedLatest

Policy revised with effective date May 1, 2026; minor edits clarifying that site-of-service review applies only to ILR and ILR criteria clarified; header added that SOS review does not apply to IHS facilities.