## **What is HCPCS code A9277?**
HCPCS code A9277 describes “Transmitter; external, for use with non-durable medical equipment interstitial continuous glucose monitoring system.” This transmitter wirelessly sends glucose data from a subcutaneous or implanted sensor to a receiver, smartphone, or insulin pump, allowing for real-time tracking of blood-glucose levels in people with diabetes to help improve glycemic control.
A9277 applies to adjunctive continuous glucose monitor (CGM) devices, also called non-therapeutic CGMs, which supplement but do not replace traditional finger-stick testing. These systems are not classified as durable medical equipment (DME) and therefore do not qualify for Medicare Part B coverage.
Common systems using A9277-classified transmitters include older CGM devices such as the Medtronic Guardian Connect and Dexcom G4/G5, which require confirmatory blood-glucose testing and are not considered therapeutic continuous glucose monitors. Each transmitter typically lasts 3–12 months, depending on manufacturer specifications and the prescribed monitoring schedule.
## **HCPCS code A9277 documentation requirements**
Although A9277 is non-covered under Medicare, proper documentation is still required for commercial or private payers that may allow coverage on a case-by-case basis.
- A valid physician’s order must specify the medical necessity of a CGM system and its transmitter component. The order should include the patient’s diabetes diagnosis, frequency of monitoring, and duration of use.
- Supporting documentation must demonstrate that the patient meets clinical eligibility criteria for CGM use. This includes a confirmed diabetes diagnosis, current insulin therapy, and a medical need for frequent glucose monitoring—typically four or more times daily.
- The documentation should specify the manufacturer, model, and serial number or unique identifier of the transmitter. The record should also indicate the date of issue and the replacement schedule, if applicable.
- Suppliers must retain proof of delivery and a Standard Written Order (SWO) that aligns with (Durable Medical Equipment, Prosthetics, Orthotics, and Supplies (DMEPOS) requirements. These records ensure that the claim complies with Medicare and payer audit standards.
## **A9277 billing requirements**
Under current CMS policy, non-therapeutic (adjunctive) CGM systems, and their components (A9276, A9277, A9278), are excluded from the Medicare DME benefit because they are not primarily and customarily used to serve a medical purpose and do not meet the definition of durable medical equipment.
- Medicare contractors deny these claims using CARC 204 (“Service not covered under the patient’s current benefit plan”).
- Suppliers must issue an Advance Beneficiary Notice of Noncoverage (ABN) before dispensing the transmitter to inform the patient of potential financial responsibility.
- Some commercial or Medicaid plans may still allow coverage under specific benefit policies or case review, so suppliers should verify payer rules before submission.
When covered by private payers, reimbursement for A9277 may be provided separately from the sensor (A9276) and receiver (A9278), though some insurers bundle all CGM components under a single payment for adjunctive systems.
## **Applicable modifiers**
Use the appropriate modifiers to indicate coverage status and billing intent for A9277:
- **GY** – Item statutorily excluded; used for non-therapeutic CGM systems not covered by Medicare.
- **GA** – ABN issued; supplier expects Medicare denial.
- **GZ** – Expected denial; no ABN provided.
- **RA** – Replacement transmitter due to loss, damage, or end of functional life.
- **KX** – Coverage criteria met for a therapeutic CGM (use with E2103, not A9277).
## **Other relevant codes**
- **E2103**: Non-adjunctive, non-implanted continuous glucose monitor or receiver
- **A9276**: Sensor; invasive (e.g., subcutaneous), disposable, for use with non-durable medical equipment interstitial continuous glucose monitoring system, one unit = 1 day supply A9276
- **A9278**: Receiver (monitor); external, for use with non-durable medical equipment interstitial continuous glucose monitoring system
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