Thank you!!!!-CS is not only for COVID-19 positive patients. It is for 1) ordering a COVID 19 test; 2) administering a COVID 19 test; or 3) evaluating to determine the need for a COVID-19 test.
-CR has a lot of nuances when it can be used, but it seems to be basically if it wouldn't be covered, but a waiver exists a disaster. I don't think it applies to your situation.
Link to the most recent CMS FAQs. https://www.cms.gov/files/document/03092020-covid-19-faqs-508.pdf
-CS is addressed on page 73, question 27. -CR is mentioned a few places, but for the full regs, see
CMS Internet Only Manual, Publication 100-04, Chapter 38, §10 https://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/Downloads/clm104c38.pdf