Understanding CGM Supply Allowances: A Guide for Suppliers

Billing supply allowances can often be confusing, particularly when it comes to billing codes for continuous glucose monitors (CGMs). Unlike standard refill requirements, these codes allow for specific items to be provided within designated time frames and understanding the distinction is crucial for accurate billing and compliance.

What Are CGM Supply Allowances?

CGM supply allowances are designed to cover a set of essential items associated with the use of CGMs, billed once every 30 days. Once a supply code is billed, suppliers are obligated to deliver all included items at no additional cost for the following 30 days. It’s important to note that any items not covered under the supply code can be billed separately, allowing for additional support as needed.

Supply Codes: A4238 and A4239

The two primary supply codes for CGMs-A4238 and A4239-each have distinct billing criteria:

  1. A4239 - Non-Adjunctive CGM Supply Allowance
    • This code covers all supplies and accessories for non-adjunctive, non-implanted CGMs.
    • Included Items:
      • CGM sensors
      • CGM transmitters
      • Home blood glucose monitor (BGM) and related supplies, including:
        • Test strips
        • Lancets
        • Lancing devices
        • Calibration solutions and batteries
    • Billing: One unit of service (UOS) can be billed every 30 days. If any of the included supplies are billed separately, those claims will be denied.
  2. A4238 - Adjunctive CGM Supply Allowance
    • This code applies to adjunctive, non-implanted CGMs and includes essential supplies for the device's operation.
    • Included Items:
      • CGM sensors
      • CGM transmitters
    • Billing: Similar to the A4239, one unit of service can be billed every 30 days. However, this code does not cover home BGM or related supplies, which can be billed separately.

Billing Guidelines

Both A4238 and A4239 can be billed for a maximum of three units of service per 90 days. To help suppliers manage their billing schedules and ensure compliance with regulations, the Continuous Glucose Monitor Supply Allowance Calculator is available. This tool assists in determining accurate billing dates and prevents errors that could lead to denied claims. Please refer to the Glucose Monitors Local Coverage Determination (LCD) for more information.

Last Updated Nov 20 , 2024