Review Correct Coding for Drug Testing
The two most specific and descriptive codes to identify and bill for drug screen testing are:
- 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
Both codes are payable per patient encounter – not per drug tested. No more than one unit of service should be billed per date of service.
G0431 is used when testing is performed in a laboratory setting on more complex equipment such as multi-channel chemistry analyzers or such instrumented systems. Use for qualitative drug screen tests that are performed in a clinical laboratory.
As a reminder, pass-through billing is not allowed. Physicians should only bill for services that they perform themselves. The laboratory performing the tests should submit the claims, not the physician’s office ordering the tests.
G0434 is used to report simple testing methods such as dipsticks, cups, cassettes and cards that are interpreted visually, with the assistance of a scanner or read using a moderately complex reader device outside the laboratory setting (i.e., within a physician's office). Use for qualitative drug screen tests that are CLIA waived and non-CLIA waived tests such as dipsticks, cups, cassettes and cards.
Modifiers are not required when billing either of these codes.
With any procedure code billed, medical necessity criteria applies.
Physicians are reminded to make every effort to utilize Blue Cross and Blue Shield of Oklahoma network providers when outsourcing laboratory services.