CurrentMass General Brigham Health PlanPolicy 014

Medical Necessity Guidelines: Continuous Glucose Monitors

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This policy governs medical-necessity and coverage determinations for continuous glucose monitors and related supplies across Medicare Advantage, Mass General Brigham ACO, One Care and Senior Care Options, and Commercial and Qualified Health Plans.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Necessity Guidelines: Continuous Glucose Monitors

Policy CodePolicy 014

Change TypeAd hoc review

Effective DateOctober 1, 2026

Last ReviewOct 1, 2026

Next Review DateNot scheduled

Key ActionThe treating endocrinologist must sign a prescription for each requested continuous glucose monitor or supply at least yearly.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

4Coverage determination pathways

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CurrentMass General Brigham Health PlanPolicy 014

Medical Necessity Guidelines: Continuous Glucose Monitors

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Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Necessity Guidelines: Continuous Glucose Monitors

Policy CodePolicy 014

Change TypeAd hoc review

Effective DateOctober 1, 2026

Last ReviewOct 1, 2026

Next Review DateNot scheduled

Key ActionThe treating endocrinologist must sign a prescription for each requested continuous glucose monitor or supply at least yearly.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

4Coverage determination pathways

Long-term sensor interval

YearlyPrescription renewal

4Exclusion categories

6Informational HCPCS codes

Coverage Criteria

Medicare Advantage

Medicare Advantage coverage follows CMS guidance.

CMS-based determination: Apply the relevant CMS National Coverage Determinations, Local Coverage Determinations, Local Coverage Articles, and Medicare-manual documentation for the requested continuous glucose monitor. When CMS provides no guidance, use Mass General Brigham Health Plan medical policies.

Applicable Medicare references include the Implantable Continuous Glucose Monitors LCDs, the Glucose Monitors LCD (L33822), and the Glucose Monitor Policy Article (A52464).

Mass General Brigham ACO

Mass General Brigham ACO coverage follows the applicable fallback sequence.

ACO determination sequence: Use MassHealth guidance for the requested durable medical equipment. If MassHealth has no guidance, use the Medicare Variation for the relevant Local Coverage Determination; if no relevant Local Coverage Determination exists, use the Commercial and Qualified Health Plans section.

MassHealth guidance includes the Guidelines for Medical Necessity Determination for Diabetes Management Devices: Continuous Glucose Monitoring Systems and Insulin Pumps.

One Care and Senior Care Options

One Care and Senior Care Options coverage uses CMS criteria first and MassHealth criteria when required.

CMS criteria first: Use CMS National Coverage Determinations, Local Coverage Determinations, Local Coverage Articles, and Medicare-manual documentation as the basis for the medical-necessity determination. When CMS provides no guidance for the requested service, or the member does not meet all CMS medical-necessity criteria, apply MassHealth medical-necessity guidelines.

If Medicare Advantage criteria are not met, MassHealth criteria are applied; Medicare Advantage criteria and exclusions also apply.

Commercial and Qualified Health Plans

Commercial and Qualified Health Plan coverage is determined using InterQual criteria.

InterQual determination: Determine medical necessity for the continuous glucose monitor through InterQual criteria available through the Mass General Brigham Health Plan provider website.

Log into MassGeneralBrighamHealthPlan.org and select the InterQual Criteria Lookup link under the Resources menu.

Use of long-term CGM sensors more frequently than every 72 hours is excluded.

Replacement or repair of a home long-term CGM is excluded while the device remains under the manufacturer’s warranty.

Replacement or repair is excluded when the device is lost, stolen, or damaged due to improper care, misuse, or neglect. For a stolen or damaged item, the plan may require proof, such as a police report, pictures, or a corroborating statement.

Replacement or upgrade is excluded when the member has a functioning model and the newer or upgraded model is not medically necessary.

Devices or device features principally used for convenience and not medically necessary are excluded.

Devices or device features considered experimental and investigational are excluded.

Devices or device features principally used for convenience rather than medical necessity are not medically necessary for coverage purposes.

A newer or upgraded model is not medically necessary when the member’s existing model is functioning; replacement or upgrade in this circumstance is excluded.

Coding and Utilization Parameters

Codes listed for informational purposesHCPCS

A4238	Supply allowance for adjunctive continuous glucose monitor (CGM), includes all supplies and accessories, 1 month supply = 1 unit of service.
A4238	Supply allowance for nonadjunctive, nonimplanted continuous glucose monitor (CGM), includes all supplies and accessories, 1 month supply = 1 unit of service.
A9276	Sensor; invasive (e.g., subcutaneous), disposable, for use with interstitial continuous glucose monitoring system, 1 unit = 1-day supply.
A9277	Transmitter; external, for use with interstitial continuous glucose monitoring system.
A9278	Receiver (monitor); external, for use with interstitial continuous glucose monitoring system.
E2102	Adjunctive continuous glucose monitor or receiver.
E2103	Nonadjunctive, nonimplanted continuous glucose monitor (CGM) or receiver.

Long-term CGM sensor frequency

Maximum frequencyLong-term CGM sensors must not be used more frequently than every 72 hours.

Applies toContinuous glucose monitor sensors used for long-term monitoring.

Coverage implicationUse of sensors more frequently than every 72 hours is excluded.

Endocrinologist prescription renewal

Renewal frequencyAt least yearly.

PrescriberThe treating endocrinologist must sign the prescription.

Applies to

Provider Review and Documentation Actions

Note

Medicare Advantage Review Pathway

For Medicare Advantage members, use CMS guidance to determine medical necessity. Apply the applicable National Coverage Determination (NCD), Local Coverage Determination (LCD), Local Coverage Article (LCA), and documentation in the Medicare manuals; when CMS provides no guidance, apply the plan’s medical policies. Prior authorization is not required.

CMS reference identified at the most recent policy review: LCD—Implantable Continuous Glucose Monitors (I-CGM) (L38662).

Note

ACO Review Pathway

For Mass General Brigham ACO members, apply MassHealth guidance for medical necessity. If MassHealth has no guidance for the specific DME, use the Medicare Variation for the relevant LCD; if no relevant LCD exists, use the Commercial and Qualified Health Plans criteria. Prior authorization is not required.

MassHealth reference: Guidelines for Medical Necessity Determination for Diabetes Management Devices: Continuous Glucose Monitoring Systems and Insulin Pumps.

Clinical Background

Continuous glucose monitors (CGMs) measure glucose in interstitial fluid over short-term or long-term periods and provide continuous information about glucose fluctuations that may not be captured by intermittent testing. Systems may be standalone, integrated into insulin pumps, implantable, or noninvasive, and may require calibration with fingerstick glucose testing. In conjunction with intensive insulin regimens, CGM may help lower hemoglobin A1c in selected patients.

Definitions

Continuous Glucose Monitors

DefinitionMinimally invasive or noninvasive devices that measure glucose levels in the interstitial fluid surrounding skin cells.

Monitoring periodCGMs provide continuous information about glucose fluctuations over several days or during long-term use that may not be captured by intermittent testing.

System featuresA CGM may use a subcutaneously implanted sensor, require calibration with fingerstick glucose levels, or be built into an insulin pump.

Glycated hemoglobin

Also known asGlycated hemoglobin is also known as HbA1c.

FormationGlucose molecules react with hemoglobin to form glycated hemoglobin.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Necessity Guidelines: Continuous Glucose Monitors

Policy CodePolicy 014

Change TypeAd hoc review

Effective DateOctober 1, 2026

Last ReviewOct 1, 2026

Next Review DateNot scheduled

Key ActionThe treating endocrinologist must sign a prescription for each requested continuous glucose monitor or supply at least yearly.

SourceLink

On This Page

Each requested continuous glucose monitor or supply.

One Care and SCO Review Pathway

For One Care and Senior Care Options (SCO) members, first apply CMS guidance, including applicable NCDs, LCDs, LCAs, and Medicare-manual documentation. If CMS has no guidance or the member does not meet all Medicare Advantage criteria, apply MassHealth medical-necessity guidelines; prior authorization is not required.

Apply the Medicare Advantage criteria and exclusions first.
When Medicare Advantage criteria are not met, apply MassHealth criteria.

Note

Commercial and QHP Review Pathway

For Commercial and Qualified Health Plan members, determine medical necessity using InterQual® criteria. Prior authorization is not required; providers can access the criteria by logging into Mass General Brigham Health Plan’s provider website and selecting the InterQual® Criteria Lookup link under the Resources menu.

Documentation Required

Required Clinical Documentation

The treating endocrinologist must submit the clinical information needed to determine medical necessity for the requested continuous glucose monitor or supply.

Medical history
Diabetes education received
Treatment to date
Glucose-reading logs
Pertinent laboratory testing
Treatment plan
Medical-necessity rationale

Documentation Required

Annual Endocrinologist Prescription

The treating endocrinologist must sign a prescription for each requested continuous glucose monitor or supply at least once every year.

Obtain a new or renewed treating-endocrinologist prescription at least annually for each requested CGM or supply.

Documentation Required

Proof for Stolen or Damaged Equipment

For replacement or repair of a home long-term CGM that is lost, stolen, or damaged, the plan may require proof of the incident before reviewing the request.

Possible proof includes a police report, photographs of the stolen or damaged item, or a corroborating statement.

Denial Risk

Long-Term CGM Exclusions

Long-term CGM coverage excludes certain replacement, frequency, convenience, and non-medically-necessary upgrade requests.

Sensors used more frequently than every 72 hours.
Replacement or repair while the device remains under the manufacturer’s warranty.
Replacement or repair when the device was lost, stolen, damaged through improper care, misuse, or neglect, or when the member has a functioning model and a newer or upgraded model is not medically necessary.
Devices or device features principally used for convenience and not medically necessary.
Devices or device features considered experimental and investigational.

Denial Risk

Insufficient Clinical Support

A request may not meet medical-necessity review when the required clinical support from the treating endocrinologist is incomplete or not provided. Ensure the documentation and annual prescription requirements are satisfied before submission.

Missing required endocrinologist documentation can result in an unsuccessful medical-necessity determination.

Red blood cell lifespanThe reaction occurs during the normal approximately 120-day life span of a red blood cell.

Clinical useThe buildup of glycated hemoglobin reflects average glucose exposure over the cell's life cycle and helps assess the effectiveness of diabetes therapy.

Hypoglycemia

Treatment thresholdA blood glucose value of 70 mg/dL or less warrants treatment with fast-acting carbohydrates.

Clinically significant thresholdA blood glucose value below 54 mg/dL is serious, clinically significant hypoglycemia.

Severe hypoglycemiaSevere hypoglycemia is severe cognitive impairment requiring assistance from another person for recovery.