United Healthcare initiated a national project as of September 1, 2018 in which all qualifying lab codes billed (with the QW modifier) are subject to an edit that cross references with the CMS CLIA database to ensure all provider/billing data on file is consistent with what’s presented on the current claim. Per the representative we spoke with in early December, this edit had resulted in the rejection of more than 461,000 claims at the time. For any practice submitting a CLIA # with their lab codes, it is strongly suggested to verify the practice information on the CLIA certificate corresponds with how claims are populating.