ICD-10-CM > S00-T88 > S30-S39 > S31 > S31.0 > S31.03 > S31.031 S31.031 Puncture wound without foreign body of lower back and pelvis with penetration into retroperitoneum Non-Billable/Non-Specific Codes S31.031A..., initial encounterS31.031D..., subsequent encounterS31.031S..., sequela