Continuous Glucose Monitoring (implantable and non-implantable)
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Policy governing coverage and prior authorization rules for implantable and non-implantable continuous glucose monitors (CGMs) for BCBSRI members, with separate rules for Medicare Advantage and Commercial products.
No material clinical or coverage changes in this revision.
Coverage Criteria for Continuous Glucose Monitoring
Medicare Advantage — Implantable CGM (I-CGM) Medical Necessity
Implantable continuous glucose monitors (Medicare Advantage) are medically necessary when ALL of the following are met:
All conditions required
Non-Implantable Therapeutic CGM
Coverage and coding depend on device classification (therapeutic vs adjunctive), payer type, and meeting device/PDAC/FDA training criteria.
Medicare Advantage follows CMS therapeutic CGM definition; BCBSRI requires PDAC listing for K0554.
Adjunctive (Non-therapeutic) CGM
Adjunctive CGMs (historically non-therapeutic) coverage depends on CMS rules and HCPCS coding.
Claims for adjunctive CGMs that do not meet DME definition may be denied as non-covered.
Implantable CGM (I-CGM)
Implantable CGM (Eversense) coverage and procedures
Practitioner training required by FDA labeling; device described as implantable fluorescence-based sensor with transmitter and mobile app.
Ambulatory CGM Professional Services
Professional/technical services for ambulatory CGM
These CPT codes apply when monitoring is performed for a minimum of 72 hours.
The following supply items and device categories are excluded from coverage: alcohol or peroxide antiseptics (HCPCS A4244, A4245) and betadine or phisoHex antiseptics (HCPCS A4246, A4247), because they are not required for device function. Urine reagent strips (HCPCS A4250) used in conjunction with a CGM are not covered. Reflectance colorimeter devices intended for clinical settings are not covered as home durable medical equipment due to the need for frequent professional recalibration. Also excluded are glucose monitors not designed for home use (HCPCS A9270) and home blood glucose disposable monitors including test strips (HCPCS A9275), which do not meet the DME definition.
For Medicare Advantage plans, BCBSRI treats several HCPCS codes as not covered even though they remain covered for Commercial products. Specifically, HCPCS A9276, A9277, A9278, S1030, and S1031 are not covered for Medicare Advantage. Effective 4/1/2022 adjunctive receivers and supplies should be billed under HCPCS E2102 and A4238, and claims for the transitional period (2/28/2022–3/31/2022) used E1399/A9999 as directed.
Services that are determined to be not medically necessary or that are non-covered benefits under the member's subscriber or employer agreement are excluded from coverage. Providers should verify member-specific benefits and eligibility; when a service is non-covered the provider may not charge the member unless the member provided prior written agreement to pay out-of-pocket.
For Commercial products, the policy states that the use of implantable CGM devices is considered not medically necessary because the evidence is insufficient to determine effects on health outcomes; therefore implantable CGM insertion and related claims are not covered for commercial members under this policy.
Historically, CMS classified CGMs that were approved only as adjunctive (non-therapeutic) devices as not covered under Medicare because they were not intended to replace blood glucose monitors for making diabetes treatment decisions. CMS Ruling 1682R explains that adjunctive CGMs were not considered to serve the medical purpose of making treatment decisions and thus were non-covered; the final rule published 12/28/2021 later expanded the DME classification so some adjunctive systems meeting the DME definition may be covered for dates of service on or after February 28, 2022.
When a service is determined to be non-covered or not medically necessary, BCBSRI requires providers to verify member benefits and follow participation agreements. Providers may not bill or collect payment from the member for such non-covered services except when the member has been informed in advance and has provided written agreement to assume financial responsibility.
Coding and HCPCS/CPT/Modifier Guidance
| A4244 | Alcohol or peroxide (not covered) |
| A4245 | Alcohol or peroxide (not covered) |
| A4246 | Betadine or phisoHex (not covered) |
| A4247 | Betadine or phisoHex (not covered) |
| A4250 | Urine test reagent strips or tablets (not covered when used with CGM) |
| A9270 | Glucose monitors not designed for home use (statutorily not covered) |
| A9275 | Home blood glucose disposable monitor, including test strips (not covered) |
| KX | Modifier when beneficiary is insulin treated |
| KS | Modifier when beneficiary is non-insulin treated |
| K0553 | Supply allowance for therapeutic continuous glucose monitor (CGM), includes all supplies and accessories, 1 month supply = 1 unit of service |
| K0554 | Receiver (monitor), dedicated, for use with therapeutic continuous glucose monitor system |
| 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 |
| S1030 | Continuous non-invasive glucose monitoring device, purchase |
| S1031 | Continuous non-invasive glucose monitoring device, rental, including sensor, sensor replacement, and download to monitor |
| 0446T | Creation of subcutaneous pocket with insertion of implantable interstitial glucose sensor, including system activation and patient training |
| 0447T | Removal of implantable interstitial glucose sensor from subcutaneous pocket via incision |
| 0448T | Removal of implantable interstitial glucose sensor with creation of subcutaneous pocket at different anatomic site and insertion of new implantable sensor, including system activation |
| 95249 | Ambulatory continuous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minimum of 72 hours; patient-provided equipment, sensor placement, hook-up, calibration of monitor, patient training, and printout of recording |
| 95250 | Ambulatory continuous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minimum of 72 hours; sensor placement, hook-up, calibration of monitor, patient training, removal of sensor, and printout of recording |
| 95251 | Ambulatory continuous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minimum of 72 hours; interpretation and report |
Provider Actions, Prior Authorization, and Billing Steps
Prior Authorization and Benefits Verification
Prior authorization is required for Medicare Advantage Plans for implantable continuous glucose monitors (I-CGM) and must be obtained via BCBSRI's online prior authorization tool for participating providers. For retail pharmacy–sourced Dexcom and Abbott FreeStyle Libre non-implantable systems obtained under the pharmacy benefit, authorization is required through BCBSRI's Pharmacy Benefit Management (PBM) vendor (covermymeds.com). Devices obtained from a Durable Medical Equipment (DME) provider do not require PBM authorization. Verify member-specific benefits and prior authorization requirements before ordering.
- Medicare Advantage I-CGM prior authorization: use BCBSRI online PA tool.
- Retail pharmacy CGM (Dexcom, Abbott FreeStyle Libre): PBM authorization via covermymeds.com.
- DME-sourced CGM supplies: authorization may not be required — verify benefits.
Adjunctive CGM Billing (effective 4/1/2022)
Effective for dates of service on or after April 1, 2022, adjunctive (non-therapeutic) CGM receivers and supplies must be billed using HCPCS code E2102 (adjunctive CGM or receiver) for the device and A4238 for the monthly supply allowance. Up to a 90-day supply of A4238 may be billed (1 unit = 1 month supply). For the transitional period February 28, 2022 through March 31, 2022, use E1399 or A9999 if needed. Do NOT file adjunctive device or supply claims with A9276–A9278; BCBSRI requires E2102 and A4238 for adjunctive CGMs.
Therapeutic CGM Billing and Authorization
For therapeutic CGM devices and supplies, bill HCPCS codes K0554 (receiver/monitor) and K0553 (monthly supply allowance, 1 unit = 1 month; up to 90-day supply may be billed). BCBSRI requires PDAC listing for devices to be covered under K0554. It is incorrect to file therapeutic devices/supplies under A9276–A9278.
- Therapeutic device code: K0554 (receiver/monitor).
- Therapeutic supply code: K0553; 1 unit = 1 month; up to 90-day supply reimbursable.
- PDAC product classification required for coverage under K0554.
- Do not bill therapeutic devices/supplies with A9276–A9278.
Supply Modifiers and Limits
Per CMS and BCBSRI rules, supply modifiers MUST be appended to HCPCS supply codes on every claim: use modifier KX when the member is insulin treated and KS when the member is non-insulin treated. Do NOT use KX for members who are not treated with insulin injections. Follow BCBSRI unit limits for diabetic testing supplies when applicable.
Audit and Documentation
BCBSRI may audit services and claim documentation for any member. Providers must maintain and make available all documentation upon request. Failure to provide requested records during an audit may result in denial or retraction of payment. Be prepared to produce documentation that supports medical necessity, PA approvals, PDAC listings, and records of any required in-person visits or training.
- Maintain documentation of in-person visits (e.g., treating physician visit within six months for I-CGM Medicare Advantage).
- Retain records of prior authorizations, PDAC product classification, and FDA labeling/practitioner training when applicable (e.g., Eversense).
- Failure to produce records upon audit may lead to denial or repayment.
Denial Risk and Member Billing
Services determined not to be medically necessary or not covered by the member's benefit plan may be denied. If a service is non-covered, providers may not bill the member unless the member was informed in advance and agreed in writing to be financially responsible. Medicare will deny non-therapeutic CGMs that do not meet CMS therapeutic definitions; such claims are non-covered. Verify benefit coverage and obtain required authorizations to reduce denial risk.
- Non-therapeutic CGMs that do not meet CMS therapeutic definition will be denied as non-covered for Medicare Advantage.
- Do not bill members for non-covered services unless an advance written agreement exists.
- Verify eligibility and coverage prior to providing services to avoid denial and balance-billing issues.
Background and Context
Continuous glucose monitoring (CGM) systems measure interstitial glucose at frequent intervals (typically every 5–10 minutes) and can function as adjuncts to, or replacements for, traditional self-monitoring of blood glucose. Therapeutic CGMs provide readings intended to be used to make diabetes treatment decisions (for example, insulin dosing) without confirmatory fingerstick testing, while adjunctive (non-therapeutic) CGMs were historically intended to complement, not replace, blood glucose meters. Frequent glucose monitoring and appropriately used CGM technology can support tighter glycemic control, though tighter control may increase hypoglycemia risk, particularly in type 1 diabetes.
Definitions
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