CMS is issuing this memorandum to clarify CLIA guidance during the COVID-19 public health emergency related to the temporary testing site multiple site exception and the enforcement discretion related to remote testing. The CLIA regulations allow for laboratories to operate with a multiple site exception to its certificate as outlined in the CLIA regulations at §§493.35(b)(1), 493.43(b)(1)and 493.55(b)(1). Operating under a multiple site exception allows laboratories the flexibility to expand access to SARS-CoV-2 testing by way of temporary testing sites during the COVID-19 public health emergency. The CLIA regulations do not define a temporary testing site or limit the number of temporary sites under a single CLIA certificate. CMS is clarifying notification requirements for temporary testing sites. CMS is clarifying the enforcement discretion related to remote review of clinical laboratory data, results and pathology slides outlined in QSO-20-21-CLIA.