What services do we append the “CS” modifier to for Medicare beneficiaries?
On April 7, 2020 CMS published the MLN Special Edition Bulletin linked below alerting providers that they would be re-purposing modifier “CS” in light of the COVID-19 public health emergency. For claims with dates of service on or after March 18, 2020 CMS states that the CS modifier should be appended to evaluation and management services that either:
- Result in the order for or the administration of a COVID-19 test, or
- Are related to furnishing or administering such a test, or
As it stands today, per CMS regulation, modifier CS is only applicable to evaluation and management codes and only in the clinical scenarios described above. When the CS modifier is appended to an E&M service this will result in the line item being reimbursed at 100% of the Medicare allowable with no patient responsibility. We would note that COVID-19 diagnostic laboratory tests themselves (as well as all other medically necessary lab tests) already carry no patient responsibility for Medicare beneficiaries, therefore modifier CS does not need to be appended to COVID-19 lab CPT or HCPCs codes for Medicare claims.
CMS MLN Special Bulletin on Modifier CS: