CMS Issues Instructions for Modifier CS for COVID Cost Sharing Waivers

Yesterday, CMS issued an update regarding the use of modifier CS for cost sharing waivers effective March 18, 2020 through the end of the Public Health Emergency (PHE). 

Modifier CS should be appended to any evaluation and management (E/M) service that was performed and resulted in the provider ordering one of the COVID-19 lab tests (U0001, U0002, 87635).   

Modifier CS will identify the service as being subject to the cost sharing waiver and will allow providers to receive 100% of the fee schedule payment, including patient coinsurance and/or deductible amounts.

Modifier CS should be appended to the following E/M services, not the lab test since cost sharing is already waived for labs.

  • Office and other outpatient services
  • Hospital observation services
  • Emergency department services
  • Nursing facility services
  • Domiciliary, rest home, or custodial services
  • Home services
  • Online digital E/M services

The CMS instructions indicate providers should NOT charge Medicare patients any co-insurance and/or deductible amounts for services reported with the CS modifier. 

If professional claims were not initially submitted with the CS modifier on or after March 18, 2020, CMS MACs must be notified and a request made to resubmit applicable claims with the CS modifier to get 100% payment.

For institutional claims not initially submitted on or after March 18, 2020, providers and hospitals must resubmit the applicable claims with the CS modifier to get 100% payment.

CMS also released a video on Medicare coverage and payment of virtual services with answers to commonly asked questions about the telehealth benefit.

The entire update, including a link to the video, can be viewed here:

We recommend referring to the CMS and other regulatory sites frequently as changes and updates are occurring rapidly.  CMS has a dedicated page on their website for all emergency updates here:

HBE is available to assist with the training of your providers and staff on the wide range of changes and can also provide assistance with policy revisions, auditing and other compliance needs you may have.  We will continue to monitor these important developments.

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