ICD-10-CM > S00-T88 > T36-T50 > T37 > T37.5 > T37.5X > T37.5X5 T37.5X5 Adverse effect of antiviral drugs Non-Billable/Non-Specific Codes T37.5X5A..., initial encounterT37.5X5D..., subsequent encounterT37.5X5S..., sequela