Clarification on the Proper Use of the CS Modifier

Per MLN Matters® article SE20011, the CS modifier (cost-sharing waiver for COVID-19 testing) is applicable to certain services furnished beginning on 3/18/2020 through the end of the PHE, 5/11/2023. “Outpatient providers, physicians and other providers and suppliers that bill Medicare for Part B services under these payment systems should use the CS modifier on applicable claim lines to identify the service as subject to the cost-sharing waiver for COVID-19 testing-related services and should not charge Medicare patients any co-insurance and/or deductible amounts for those services.”

Note that the CS modifier should not be applied to laboratory test services since deductible and co-insurance does not apply.

On a quarterly basis, CMS revises the Integrated OCE (I/OCE) code files. The I/OCE program processes claims for all outpatient institutional providers including hospitals that are subject to the OPPS as well as hospitals that are not (Non-OPPS). Specific to the PHE, the quarterly I/OCE files identify HCPCS codes that are eligible for coinsurance and deductible.

Providers may locate HCPCS codes that are eligible for the deductible and coinsurance waiver by using the files posted to the CMS for I/OCE Quarterly Release File website.

Please follow these instructions for accessing these files:

• Select and download the appropriate “ I/OCE Quarterly Data Files” based on the date of service
• Open the folder “Report-Tables”
• Select and open the excel file “Data_HCPCS”
• Scroll to the far right to locate the column identified as “COINSURANCE_DEDUCTIBLE_WAIVER_ELIGIBLE”
• The values for this column are:
  • 0 = Not applicable
  • 1 = Applicable

Revised 4/10/2023