Question: How should we report an antibody test (AS0) that we conduct to identify previous strep infections? Wisconsin Subscriber Answer: A common definitive test for streptococcus antibody detection is the antistreptolysin 0 titer (AS0 titer). Report the service as 86060 (Antistrep-tolysin 0; titer). The assay identifies an antecedent streptococcus group A infection using a blood test, often to diagnose streptococcal involvement in disease processes such as rheumatic fever (390-392.x) and its possible complications of carditis (391.x, 429.89, 714.2) or rheumatoid arthritis (714.0). Reader Questions and You Be the Coder were answered and/or reviewed by R.M. Stainton Jr., MD, president of Doctors' Anatomic Pathology Services in Jonesboro, Ark.; and Laurie Castillo, MA, CPC, CPC-H, CCS-P, member of the national advisory board of the American Academy of Professional Coders (AAPC) and president of Physician Coding and Compliance Consulting in Virginia.