Please help i have read the guidelines in icd-10 about 10 time and i can not find the answer. Patient comes for an annual exam z00.00 or z01.419 and the provider orders sti test. In icd-9 we used v74.5 screening for sexually transmitted disease. In icd-10 i used z11.3 encounter screening for infection with a predominantly sexual mode of transmission. Bcbs denied claim stating it is not a medical diagnosis. We see a lot of patients for screening sti's with no signs or symptoms. Please help me with correct coding for this process.