February 20, 2024
Continuous Glucose Monitors (CGMs) Supply Allowance Billing Reminder
CGM Supply Allowance HCPCS codes A4238 and A4239 Include:
- A4238 (supply allowance for adjunctive, non-implanted CGM) includes all items necessary for the use of the device.
- Do not bill these items separately: CGM sensors and transmitters.
- Code A4238 does not include a home blood glucose monitor and related BGM testing supplies and you may bill these items separately.
- A4239 (supply allowance for non-adjunctive, non-implanted CGM) includes all items necessary for the use of the device.
- Do not be bill these items separately: CGM sensors, CGM transmitters, home blood glucose monitors (BGMs), related BGM supplies (test strips, lancets, lancing devices, and calibration solutions), batteries, or any other items needed to use the device.
How often can we bill the supply allowance?
Dates of service on and after 01/01/24
- The supply allowance (code A4238 or A4239) is a monthly allowance. You may bill code A4238 or A4239 up to a maximum of three units of service per 90 days at a time.
- Do not span the date of service for HCPCS A4328 and A4239. The "From" and "To" date fields on the claim should be the same.
- Use the Continuous Glucose Monitor (CGM) Supply Allowance Date of Service (DOS) Calculator to confirm the next date of service to bill.
Dates of service prior to 01/01/24
- Only bill one month of the supply allowance at a time.
- Do not bill more than one unit of service of HCPCS code A4238 or A4239 per 30 days.
- February does not have 30 days, so you must adjust your billing schedule if you bill on the same date each month.
KS, KX, and CG Modifiers:
- Use modifier KX if the beneficiary is insulin-treated.
- Use modifier KS if the beneficiary is not insulin-treated.
- Use modifier CG only if all of the therapeutic CGM coverage criteria 1-6 in the Glucose Monitor Local Coverage Determination (LCD) (L33822) are met.
- When LCD requirements are met, you must add the KX modifier and the CG modifier to both the CGM device and the supply allowance.
- Do not use the KX modifier if the beneficiary is not insulin-treated.
- Do not use the CG modifier if any of the coverage criteria are not met.
- Do not use the KS and KX modifier at the same time.
KF Modifier:
The KF modifier is a pricing modifier and must be reported with the CGM and the supply allowance when the CGM is classified as a Class III device. If the CGM is not a Class III device, do not use the KF modifier. Contact the Pricing, Data Analysis and Coding Contractor (PDAC) for help with correct coding.
See the Glucose Monitor Local Coverage Determination (LCD) (L33822) and Glucose Monitor – Policy Article (A52464) for complete information about payment rules, policy specific documentation requirements, modifiers, and coding guidelines for these items.