ICD-10-CM › M00-M99 › M20-M25 › M21.9 Unspecified acquired deformity of... › M21.95

This code exists but cannot be submitted on its own. It groups the more specific codes beneath it.

A category header for its whole life, FY2016 onwards. It has never been valid for submission on its own.

Submit one of these 3 more specific codes instead:

• M21.951 Unspecified acquired deformity of right thigh
• M21.952 Unspecified acquired deformity of left thigh
• M21.959 Unspecified acquired deformity of unspecified thigh

What has happened to this code

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

Inherited from M21 Other acquired deformities of limbs

Excludes1 - never coded here

• acquired absence of limb (Z89.-)
• congenital absence of limbs (Q71-Q73)
• congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74)

Excludes2 - not included here

• acquired deformities of fingers or toes (M20.-)
• coxa plana (M91.2)

Inherited from the M20-M25 section Other joint disorders (M20-M25)

Excludes2 - not included here

• joints of the spine (M40-M54)

How CDC's index refers to this code

Wording from the official alphabetic index. Much of it appears nowhere in the code description, which is why a search for the everyday phrase so often finds nothing.

• Bruck's disease
• Deformity > hip
• Deformity > thigh
• Deformity > leg NEC
• Deformity > rotation
• Deformity > limb > thigh
• Deformity > joint NEC > hip

Codes in the same group

Code	Description	Status
M21.90	Unspecified acquired deformity of unspecified limb	Valid
M21.92	Unspecified acquired deformity of upper arm	Not billable
M21.93	Unspecified acquired deformity of forearm	Not billable
M21.94	Unspecified acquired deformity of hand	Not billable
M21.96	Unspecified acquired deformity of lower leg	Not billable