CPT 80301 is per date of service so if additional drugs were tested it would fall under one unit of service. HCPCS G0434 & G0431 are stated per their descriptor as per patient encounter, which described in the NCCI policy manual. The LCD that I reviewed described using a second method if the results were unexpected and certain criteria was met, but it did not describe repeating the same test method over and billing for repeating the same test method.
80301 Drug screen, any number of drug classes from Drug Class List A; single drug class method, by instrumented test systems (eg, discrete multichannel chemistry analyzers utilizing immunoassay or enzyme assay), per date of service
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NCCI Policy manual
HCPCS code G0434 (drug screen..., by CLIA waived test or moderate complexity test, per patient encounter) is utilized to report urine drug screening performed by a test that is CLIA waived or CLIA moderate complex. The code is reported with only one (1) unit of service regardless of the number of drugs screened. HCPCS code G0431 (drug screen... by high complexity test method..., per patient encounter) is utilized to report drug urine screening performed by a CLIA high complexity test method.
This code is also reported with only one (1) unit of service regardless of the number of drugs screened. If a provider performs urine drug screening, it is generally not necessary for that provider to send an additional specimen from the patient to another laboratory for urine drug screening for the same drugs. 5