ICD-10-CM > S00-T88 > S00-S09 > S04 > S04.8 > S04.81 S04.81 Injury of olfactory [1st ] nerve Non-Billable/Non-Specific Codes S04.811Injury of olfactory [1st ] nerve, right sideS04.811A..., initial encounterS04.811D..., subsequent encounterS04.811S..., sequelaS04.812Injury of olfactory [1st ] nerve, left sideS04.812A..., initial encounterS04.812D..., subsequent encounterS04.812S..., sequelaS04.819Injury of olfactory [1st ] nerve, unspecified sideS04.819A..., initial encounterS04.819D..., subsequent encounterS04.819S..., sequela