CurrentMass General Brigham Health PlanPolicy N/A

Medical Policy Continuous Glucose Monitors

Defines Mass General Brigham Health Plan medical necessity criteria, variations by product line (Medicare Advantage, ACO, One Care, SCO), exclusions, documentation requirements, and code list for continuous glucose monitors and related supplies. References InterQual® criteria for clinical determinations.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Policy Continuous Glucose Monitors

Policy CodePolicy N/A

Change TypeRevised (Jan 2026; Mar 2023 off-cycle)

Effective DateJul 1, 2015

Next Review DateN/A

Key ActionEndocrinologists must submit comprehensive clinical information (history, education, treatment, glucose logs, labs, treatment plan, and medical necessity rationale) and sign a yearly prescription to support InterQual®-based medical necessity determinations.

SourceLink

POLICY UPDATE CHANGES

January 2026: Annual update. Updated prior authorization table and added variation for One Care and SCO members. Fixed code disclaimer. Added hyperlinks to LCDs and LCA. Clarified and changed name of Mass General Brigham ACO Variation. References updated.

March 2023: Off-cycle update. Prior authorization no longer required. Table updated. Medicare language added. References updated.

InterQual-basedClinical criteria source

≥72 hrsMin sensor interval

9Medicare refs

Coverage Summary

This policy states that Continuous Glucose Monitors (CGMs) are covered with criteria by Mass General Brigham Health Plan and that medical necessity determinations are made using InterQual® criteria. The policy notes plan-specific variations (Medicare Advantage, Mass General Brigham ACO / MassHealth, One Care, and Senior Care Options (SCO)) and that the plan defers to CMS or MassHealth guidance where applicable.

The policy includes explicit exclusions (for example, sensor use more frequently than every 72 hours, replacement/repair exclusions when under manufacturer warranty or lost/stolen/damaged due to misuse, and devices/features that are convenience or experimental) and specifies documentation requirements such as the endocrinologist providing medical history, diabetes education, treatment to date, glucose logs, pertinent labs, treatment plan and rationale, and an annual prescription signature.

Effective/last review dates: policy effective date originally July 2015 with the listed updates; most recent documented annual update entry is January 2026 and the policy history includes a March 2023 off-cycle update noting prior authorization changes.

Key facts

Clinical criteria sourceInterQual-based

Minimum sensor use interval≥72 hours

Medicare LCD/LCA references listed9

Sensor use frequency thresholdNo more frequently than every 72 hours

StatusCURRENT

SubjectContinuous Glucose Monitors (CGM)

Medical Necessity Criteria

General Coverage / Medical Necessity

Covered when ALL of the following are met:

ALL of the following

Continuous glucose monitors are recommended by the member's providers
The request meets the medical necessity criteria as determined using InterQual® criteria
Access InterQual® via MassGeneralBrighamHealthPlan.org Resources Menu
The member's endocrinologist provides all necessary clinical information for determination of medical necessity, including medical history, diabetes education received, treatment to date, glucose reading logs, pertinent laboratory testing, treatment plan, and medical necessity rationale
The treating endocrinologist signs a prescription for any requested CGM/supply at least yearly

Coding

Informational CGM and supply codes (inclusion does not imply coverage)HCPCS

A4238	Supply allowance for adjunctive continuous glucose monitor (CGM), includes all supplies and accessories, 1 month supply = 1 unit of service
A4239	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

Provider Actions & Requirements

Prior Authorization

InterQual® criteria authorization pathway

Medical necessity determinations for continuous glucose monitors are made using InterQual® criteria. Providers must access InterQual® via the plan provider website to support authorization decisions.

Access InterQual® via MassGeneralBrighamHealthPlan.org Resources Menu

Documentation Required

Submit clinical information and rationale

The treating endocrinologist must supply clinical documentation to support medical necessity, including: medical history, diabetes education received, treatment to date, glucose reading logs, pertinent laboratory testing, an explicit treatment plan, and a rationale explaining medical necessity.

Background

Continuous Glucose Monitors (CGMs) are minimally invasive or noninvasive devices that measure interstitial glucose over short-term or long-term use and may require fingerstick calibration. Several CGMs and insulin pump systems with built-in CGMs have been FDA-approved.

Clinically, CGM used in conjunction with intensive insulin regimens can be a useful tool to lower hemoglobin A1c levels in selected patients. The plan specifies that medical necessity for CGMs is determined through InterQual® criteria and requires providers to access InterQual® via the plan provider website for determinations.

For Medicare Advantage, One Care, and SCO members the plan uses guidance from the Centers for Medicare & Medicaid Services (CMS) — including NCDs, LCDs, and LCAs — for determinations. For members of the Mass General Brigham ACO the plan uses MassHealth guidance where applicable and otherwise relies on its medical policies.

Medicare LCD / LCA References

Type	Name	Number	Effective Date
LCD	Implantable Continuous Glucose Monitors (I-CGM)	L38662 / L38664 / L38623 / L38657 / L38659 / L38617 / L38743 / L38686
LCD	Glucose Monitors	L33822	2023-04-16
LCA	Glucose Monitor - Policy Article	A52464	2023-04-16

Definitions and Evidence

Continuous Glucose Monitors: Minimally invasive or noninvasive devices that measure glucose levels in the interstitial fluid surrounding skin cells over several days or long-term; may require calibration with fingerstick glucose levels; includes implantable and non-implantable systems.

Glycated hemoglobin (HbA1c): Form of hemoglobin reflecting average glucose exposure; the ADA diagnostic criterion is >= 6.5% for diabetes.

Hypoglycemia: Blood glucose ≤ 70 mg/dL is sufficiently low for treatment with fast-acting carbohydrates; <54 mg/dL is considered serious/clinically significant; severe hypoglycemia requires assistance from another person.

InterQual criteria are used for medical necessity determinations for CGMs; the policy directs providers to access InterQual® via the Mass General Brigham Health Plan provider website. The policy does not reproduce specific diagnostic thresholds from InterQual® within the document.

Policy history notes material updates (for example, January 2026 annual update adding One Care and SCO variation and updating the prior authorization table, and a March 2023 off-cycle update noting prior authorization no longer required for some lines) but clinical criteria continue to reference InterQual®.

Revision History

March 2023off-cycle update

Off-cycle update: prior authorization no longer required; prior authorization table updated; Medicare language added; references updated.

January 2026annual updateLatest

Annual update: added One Care and SCO variation; updated prior authorization table; fixed code disclaimer; added hyperlinks to LCDs and LCA; clarified and changed name of Mass General Brigham ACO variation; references updated.