ICD-10-CM 2027
ICD-10 code for flank bite
Open bite of abdominal wall, unspecified flank without penetration into peritoneal cavity
From the official ICD-10-CM alphabetic index entry “Bite (s) (animal) (human) › flank”. Page updated September 29, 2026.
About coding flank bite
The ICD-10-CM code for flank bite is S31.15A (Open bite of abdominal wall, unspecified flank without penetration into peritoneal cavity). The official index lists 7 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on S31.15A.
Within S31.15, choose S31.15A (unspecified flank without penetration into peritoneal cavity) only when documentation doesn't support a more specific option: right upper quadrant without penetration into peritoneal cavity (S31.150), left upper quadrant without penetration into peritoneal cavity (S31.151), epigastric region without penetration into peritoneal cavity (S31.152), right lower quadrant without penetration into peritoneal cavity (S31.153), left lower quadrant without penetration into peritoneal cavity (S31.154), periumbilic region without penetration into peritoneal cavity (S31.155), right flank without penetration into peritoneal cavity (S31.156), left flank without penetration into peritoneal cavity (S31.157) and 1 more.
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It was added in FY2026, effective October 1, 2025.
More specific flank bite codes (official index)
- with penetration into peritoneal cavity S31.65A — Open bite of abdominal wall, unspecified flank with penetration into peritoneal cavity
- left S31.157 — Open bite of abdominal wall, left flank without penetration into peritoneal cavity
- with penetration into peritoneal cavity S31.657 — Open bite of abdominal wall, left flank with penetration into peritoneal cavity
- right S31.156 — Open bite of abdominal wall, right flank without penetration into peritoneal cavity
- with penetration into peritoneal cavity S31.656 — Open bite of abdominal wall, right flank with penetration into peritoneal cavity
- superficial S30.87A — Other superficial bite of flank
- insect S30.86A — Insect bite (nonvenomous) of flank
Common questions about flank bite ICD-10 codes
What is the ICD-10 code for flank bite?
- S31.15A — Open bite of abdominal wall, unspecified flank without penetration into peritoneal cavity (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: S31.65A, S31.157, S31.657, S31.156 and others below.
What is the ICD-10 code for left flank bite?
- S31.157 — Open bite of abdominal wall, left flank without penetration into peritoneal cavity (header code; choose a more specific subcode).
What is the ICD-10 code for right flank bite?
- S31.156 — Open bite of abdominal wall, right flank without penetration into peritoneal cavity (header code; choose a more specific subcode).
What is the ICD-10 code for superficial flank bite?
- S30.87A — Other superficial bite of flank (header code; choose a more specific subcode).
Is S31.15A billable?
- No. S31.15A is a header code. Report one of its more specific subcodes instead.