Question: Our lab performs a hepatitis C screening for a Medicare patient with an injection drug use habit. How should we code this? Iowa Subscriber Answer: Code the test for a Medicare beneficiary as G0472: Hepatitis C antibody screening, for individual at high risk and other covered indication(s). Appropriate diagnosis coding for the encounter would be Z11.59 (Encounter for screening for other viral diseases) and Z71.51 (Drug abuse counseling and surveillance of drug abuser).