Continuous Glucose Monitor (CGM) Supply Allowance

The billing codes A4238 and A4239 for continuous glucose monitor (CGM) supplies have a maximum limit of three units of service (UOS) per ninety days. Refill requirements do not apply to these codes. The next billable date for a 30-day supply is 31 days from the last billing date, while for a 90-day supply, it is 91 days from the last billing date. Non-adjunctive CGM supplies under code A4239, including sensors, transmitters, and home blood glucose monitor supplies, must be billed as 1 UOS per 30 days, allowing up to 3 UOS starting January 1, 2024, for a 90-day supply. Adjunctive CGM devices (A4238) do not replace standard home blood glucose monitors, and the supply allowance covers all necessary items except home BGM supplies. The CGM supply allowance codes do not follow standard documentation requirements for refills, and if additional items are needed during the billing period, the DME supplier must provide them at no charge. Billing before the expected end of the current supply is not allowed, claims must not be submitted to Medicare until the appropriate time has passed. The date of service for A4238 and A4239 should not have a span date and claims with span dates will be returned as un-processable, requiring correction and resubmission. Additional information is available in the Glucose Monitors Local Coverage Determination (LCD) (L33822) and LCD-related Policy Article (A52464).

Last Updated Oct 10 , 2024