Looks like the answer is, as usual, depends:
"
Using CS Modifier When Cost-Sharing is Waived
This clarifies a prior message that appeared in our
April 7, 2020 Special Edition.
CMS now waives cost-sharing (coinsurance and deductible amounts) under Medicare Part B for Medicare patients for certain COVID-19 testing-related services. Previously, CMS made available the CS modifier for the gulf oil spill in 2010; however, CMS recently repurposed the CS modifier for COVID-19 purposes. Now, for services furnished on March 18, 2020, and through the end of the Public Health Emergency, outpatient providers, physicians, and other providers and suppliers that bill Medicare for Part B services under specific payment systems outlined in the April 7 message should use the CS modifier on applicable claim lines to identify the service as subject to the cost-sharing wavier for COVID-19 testing-related services and to get 100% of the Medicare-approved amount. Additionally, they should NOT charge Medicare patients any co-insurance and/or deductible amounts for those services."
"Note: The American Medical Association released two new testing CPT® codes after CMS published the
MLN Connects SE: 86328 and 86769. As such, CMS does not address these codes in the provider education.
CMS further outlines that cost sharing is waived for qualifying E/M services dated March 18 through the end of the public health emergency. This guideline applies to any of the following E/M services, so long as the criteria for the visit is met:
- Office and other outpatient services
- Hospital observation services
- Emergency department services
- Nursing facility services
- Domiciliary, rest home, or custodial care services
- Home services
- Online digital evaluation and management services
Furthermore, cost sharing is waived for a qualifying E/M service to any of the following:
- Hospital outpatient departments paid under the outpatient prospective payment system
- Physicians and other professionals under the physician fee schedule
- Critical access hospitals
- Rural health clinics
- Federally qualified health centers"