Billing for Drug Screening Procedures

Drug screening procedure codes G0431 and G0434 should be billed only once per patient encounter.

• G0431 – Drug screen, qualitative; multiple drug classes by high complexity test method (e.g., immunoassay, enzyme assay), per patient encounter.

• G0434 – Drug screen, other than chromatographic; any number of drug classes, by CLIA waived test or moderate complexity test, per patient encounter

There may be special circumstances when more than one drug screening procedure is required on the same day. If this occurs, you must submit an appeal for the claim along with supporting documentation demonstrating medical necessity for multiple drug screening procedures performed on the same day.