U.S. ICD-10-CM · FY 2027

M21 ICD-10-CM Code: Other acquired deformities of limbs

A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.

Code definition

Official description

M21

Other acquired deformities of limbs

ICD-10-CM diagnosis code · United States clinical modification

Classification

Where M21 sits

  1. 1

    Chapter 13

    Diseases of the musculoskeletal system and connective tissue (M00-M99)

  2. 2

    Section

    Other joint disorders (M20-M25)

  3. 3

    Category M21

    Other acquired deformities of limbs

  4. 4

    Code M21

    Other acquired deformities of limbs

More specific choices

Codes under M21

M21 is a non-billable category. Choose the child code that best matches the documented diagnosis.

M21.0

Valgus deformity, not elsewhere classified

M21.1

Varus deformity, not elsewhere classified

M21.2

Flexion deformity

M21.3

Wrist or foot drop (acquired)

M21.4

Flat foot [pes planus] (acquired)

M21.5

Acquired clawhand, clubhand, clawfoot and clubfoot

M21.6

Other acquired deformities of foot

M21.7

Unequal limb length (acquired)

M21.8

Other specified acquired deformities of limbs

M21.9

Unspecified acquired deformity of limb and hand

Documentation details

Notes for this code

Inclusion terms

No inclusion terms are listed for M21.

Code first

No “code first” instruction is listed for M21.

Use additional code

No “use additional code” instruction is listed for M21.

Excludes1

Conditions that should not be reported together with this code.

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

Excludes2

Conditions not included here that may be reported separately when present.

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

Transparency

Source and release

Data release

U.S. ICD-10-CM · FY 2027

Effective date

Oct 1, 2026

Publisher

Vero Scribe Inc.

This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.

Review the CDC/NCHS ICD-10-CM source

Code-specific guidance

Frequently asked questions

What does ICD-10-CM code M21 mean?

M21 is the FY 2027 U.S. ICD-10-CM code for “Other acquired deformities of limbs.”

Is M21 a billable or specific ICD-10-CM code?

No. M21 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.

Where is M21 located in ICD-10-CM?

M21 is listed in Chapter 13, Diseases of the musculoskeletal system and connective tissue (M00-M99), within Other joint disorders (M20-M25) (M20–M25), under category M21, Other acquired deformities of limbs.

What coding notes are listed for M21?

No inclusion terms are listed for M21 in this reference record. No code-first instruction is listed. Excludes1 notes: acquired absence of limb (Z89.-); congenital absence of limbs (Q71-Q73); congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74). Excludes2 notes: acquired deformities of fingers or toes (M20.-); coxa plana (M91.2).

Ready to transform your clinical documentation?

Join Vero and see how effortless documentation can be.

Try for free

  • No credit card required

  • Cancel anytime