MCMedicalCodingSoftware
M21.8

M21.8: Other specified acquired deformities of limbs

Non-billable headerICD-10-CM

M21.8 is a non-billable header ICD-10-CM code for other specified acquired deformities of limbs. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes2: not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

Excludes1 inherited from the categories above M21.8

A category’s note binds every code beneath it.

Written on M21: Other acquired deformities of limbs

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

Excludes2 inherited from the categories above M21.8

Not part of this code, but both may be coded when both are present.

Written on M21: Other acquired deformities of limbs

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

Other codes that can never be billed with M21.8

Their own Excludes1 notes name this code, so the conflict is not listed above.

  • M23Internal derangement of knee

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead M21.8

5 child codes. Green means billable.

Other codes under M21

ICD-10-CMFY2027· effective October 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release: see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.