ICD-10-CM 2027
ICD-10 code for Bowleg
From the official ICD-10-CM alphabetic index entry “Bowleg (s) (acquired)”. Page updated September 29, 2026.
About coding Bowleg
The ICD-10-CM code for Bowleg is M21.16 (Varus deformity, not elsewhere classified, knee). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on M21.16.
Within M21.1 (varus deformity, not elsewhere classified), M21.16 is specifically for varus deformity, not elsewhere classified, knee. Related codes cover unspecified site (M21.10), elbow (M21.12), hip (M21.15) and ankle (M21.17).
To report this condition, pick the subcode that matches the documentation: M21.161 (knee), M21.162 (knee) and M21.169 (knee).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
More specific Bowleg codes (official index)
Common questions about Bowleg ICD-10 codes
What is the ICD-10 code for Bowleg?
- M21.16 — Varus deformity, not elsewhere classified, knee (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: Q68.5, E64.3.
What is the ICD-10 code for congenital bowleg?
- Q68.5 — Congenital bowing of long bones of leg, unspecified.
What is the ICD-10 code for rachitic bowleg?
- E64.3 — Sequelae of rickets.
Is M21.16 billable?
- No. M21.16 is a header code. Report one of its more specific subcodes instead.