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Continuous Glucose Monitor (CGM) Supply Allowance Date of Service (DOS) Calculator

Enter the last date of service to calculate the next date of service that can be billed for

  • A4238 (supply allowance adjunctive, non-implanted CGMs that operate with an insulin pump)
  • A4239 (supply allowance non-adjunctive, non-implanted CGMs)

30 Day Supply
90 Day Supply

Please check same/similar in myCGS for claim history.

For additional information, see the Glucose Monitors Local Coverage Determination (LCD)External website and External Infusion Pumps Local Coverage Determination (LCD)External website.

This tool only outputs the 31st or 91st date based on the date input. The calculator is a stand-alone tool, does not interface with the claims processing system, and does not guarantee payment. Please check claims history through the myCGS web portal or the Interactive Voice Response (IVR).

Disclaimer: CGS' online tools and calculators are informational and educational tools only, designed to assist suppliers and providers in submitting claims correctly. CGS makes no guarantee that this resource will result in Medicare reimbursement for services provided. Although we've made every reasonable effort to provide effective resources, CGS is not responsible for the consequences of any decisions or actions taken in reliance upon or as a result of the information that these tools provide. CGS is not responsible for any human or mechanical errors or omissions.


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