M21

M21: Other acquired deformities of limbs

Non-billable headerICD-10-CM

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

Excludes1: never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

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, but may coexist

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

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

Other codes that can never be billed with M21

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

Z89Acquired absence of limb
M23Internal derangement of knee
Q66Congenital deformities of feet
Q66.5Congenital pes planus

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

10 child codes. Green means billable.