ICD-10-CM > V00-Y99 > W20-W49 > W21 > W21.4 W21.4 Striking against diving board Non-Billable/Non-Specific Use Additional code for subsequent falling into water, if applicable (W16.-) Codes W21.4XXA..., initial encounterW21.4XXD..., subsequent encounterW21.4XXS..., sequela