Can anyone tell me how to properly code the covid antibody test? 86328. Medicare started denying our claims for 86328 due to clia level. We currently bill it 86328 then 36415. With no modifiers on it. Our office seems to think this is a coding issue. Should we be billing this with QW? I know in the past we did and also used CS which they eventually did not like so we stopped. Any help with this would be appreciated. We have been trying to talk to other doctors offices with no response even tried contacting the manufacturer. Help!!!!!!!