Summary & Overview
HCPCS Level II A4239: Supply Allowance for Non‑implanted Non‑adjunctive CGM
Headline: HCPCS Level II code A4239 covers monthly supplies for non‑implanted, non‑adjunctive continuous glucose monitors
Lead: HCPCS Level II code A4239 designates a monthly supply allowance for non‑adjunctive, non‑implanted continuous glucose monitors (CGMs), encompassing all related supplies and accessories. The code is used by durable medical equipment suppliers and payer programs to bill one unit per month of supplies for devices intended to support ongoing glucose monitoring.
What the code represents and national significance: The code defines a standardized supply billing unit for a class of CGM products that operate without adjunctive requirements or implantation. Nationally, consistent use of this HCPCS code supports clearer claims processing, supply management, and benefit categorization for diabetes monitoring technologies.
Key payers covered: This overview references major national commercial payers: Aetna, Blue Cross Blue Shield, Cigna Health, and UnitedHealthcare.
What readers will learn: The publication provides benchmarks and policy context for billing under HCPCS Level II code A4239, explains clinical and billing boundaries between device and supply codes, and outlines typical places of service and reporting conventions. It highlights associations with durable medical equipment supplier billing practices and clarifies the unit-of-service definition (1 month = 1 unit).
Data gaps: Data not available in the input for specific payer coverage policies, reimbursement rates, and service-line level details.
Billing Code Overview
HCPCS Level II code A4239 describes a supply allowance for non‑adjunctive, non‑implanted continuous glucose monitor (CGM). The code covers all supplies and accessories associated with the device and is billed in units where 1 month supply = 1 unit of service.
Service Type: Durable Medical Equipment (supplies)
Typical Site of Service: DME Supplier (POS 32)
Clinical & Coding Specifications
Clinical Context
A patient with insulin-treated diabetes presents to a Durable Medical Equipment supplier for monthly supplies for a non‑adjunctive, non‑implanted continuous glucose monitor (CGM). The clinician documents ongoing need for CGM supplies due to impaired glucose monitoring or frequent hypoglycemia, and submits an order specifying a one‑month supply quantity. The DME supplier processes the order, bills for the supply allowance as HCPCS Level II code A4239 with the appropriate modifier (NU for new equipment on initial supply or RR if billed as a rental), and coordinates shipment to the patient for home use. Follow up visits with the ordering provider confirm continued medical necessity and adjust supply frequency as clinically indicated.
Coding Specifications
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Modifier
NU: New Equipment — used when the item is provided as new initial equipment. -
Modifier
RR: Rental — used when the supplier is billing the item as a rental rather than purchase.
Associated Provider Taxonomies
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207RE0101X: Endocrinology, Diabetes & Metabolism Physician — specialty managing diabetes care and CGM therapy. -
207Q00000X: Family Medicine Physician — primary care physicians who may order CGM supplies for patients with diabetes. -
207R00000X: Internal Medicine Physician — internists who manage adult diabetes care and may order CGM supplies.
Related Diagnoses
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E10.9— Type 1 diabetes mellitus without complicationsClinical relevance: Type 1 diabetes commonly requires intensive insulin therapy and frequent glucose monitoring; CGM supplies billed with HCPCS Level II code
A4239support continuous glucose monitoring for these patients. -
E11.9— Type 2 diabetes mellitus without complicationsClinical relevance: Some patients with type 2 diabetes use insulin or have indications for CGM;
A4239may be billed when supplies for a non‑adjunctive CGM are provided. -
E13.9— Other specified diabetes mellitus without complicationsClinical relevance: Other specified forms of diabetes that require glucose monitoring may necessitate CGM supplies billed with
A4239. -
R73.09— Other abnormal glucoseClinical relevance: Abnormal glucose findings can prompt use of CGM for diagnostic or monitoring purposes;
A4239covers the monthly supply allowance when CGM supplies are dispensed. -
Z79.4— Long term (current) use of insulinClinical relevance: Long‑term insulin therapy indicates ongoing need for glucose monitoring;
A4239is applicable when monthly CGM supplies are provided to patients on chronic insulin therapy.
Related Codes
| Code | Description |
|---|---|
E2103 | Non‑adjunctive continuous glucose monitor device |
E0607 | Home blood glucose monitor |
-
E2103relates as the device code for a non‑adjunctive CGM; HCPCS Level II codeA4239represents the monthly supply allowance associated with such a device and is commonly billed in conjunction with the device code when supplies are dispensed. -
E0607represents a home blood glucose monitor and may be an alternative or complementary device for patients who use meter testing in addition to or instead of CGM; it is not a supply allowance but a device code that may appear in the same clinical workflow.
National Reimbursement Benchmarks
National mean commercial reimbursement (BUCA) is $219.28 compared with Medicare at $0.00 for HCPCS Level II code A4239, indicating that average commercial rates exceed Medicare in the provided input. The full payer breakdown is presented in the table and chart below.
Rate dispersion (P75 minus P25) is widest for Blue Cross Blue Shield at $92.00 and relatively wide for UnitedHealthcare ($85.00) and BUCA ($79.17). Dispersion is narrowest for Cigna Health, where P25, P50, and P75 are all $145.00, indicating a very tight distribution. The table and chart below provide the complete percentile and mean values by payer.
Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.