M21 Other acquired deformities of limbs

⚠ Non-Billable ICD-10-CM 2026
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The ICD-10-CM code for Other acquired deformities of limbs is M21 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Section
M20-M25: Other joint disorders (M20-M25)
Category M21
172 codes (124 billable)
FY2026 Status
Stable since FY2024
Excludes1
Not coded here. These conditions should NOT be coded together with M21.
  • 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. These conditions are coded elsewhere but may be coded together if applicable.
  • acquired deformities of fingers or toes (M20.-)
  • coxa plana (M91.2)

Official Coding Guidelines

Osteoporosis without pathological fracture (M81)

Category M81, Osteoporosis without current pathological fracture, is for use for patients with osteoporosis who do not currently have a pathologic fracture due to the osteoporosis, even if they have had a fracture in the past. For patients with a history of osteoporosis fractures, status code Z87.310, Personal history of (healed) osteoporosis fracture, should follow the code from M81.

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.13.d.1
Osteoporosis with current pathological fracture (M80)

Category M80, Osteoporosis with current pathological fracture, is for patients who have a current pathologic fracture at the time of an encounter. The codes under M80 identify the site of the fracture. A code from category M80, not a traumatic fracture code, should be used for any patient with known osteoporosis who suffers a fracture, even if the patient had a minor fall or trauma, if that fall or trauma would not usually break a normal, healthy bone.

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.13.d.2

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

Cite This Page

Reference M21 with the canonical source and edition:

M21 — Other acquired deformities of limbs. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/M21

Canonical URL: https://icd10codingpro.com/codes/M21

Related Codes

More Specific Codes

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

All Codes in M21

Every most-specific code under M21 Other acquired deformities of limbs (124 codes):

Show the complete M21 code list
M21.00 Valgus deformity, not elsewhere classified, unspecified site M21.021 Valgus deformity, not elsewhere classified, right elbow M21.022 Valgus deformity, not elsewhere classified, left elbow M21.029 Valgus deformity, not elsewhere classified, unspecified elbow M21.051 Valgus deformity, not elsewhere classified, right hip M21.052 Valgus deformity, not elsewhere classified, left hip M21.059 Valgus deformity, not elsewhere classified, unspecified hip M21.061 Valgus deformity, not elsewhere classified, right knee M21.062 Valgus deformity, not elsewhere classified, left knee M21.069 Valgus deformity, not elsewhere classified, unspecified knee M21.071 Valgus deformity, not elsewhere classified, right ankle M21.072 Valgus deformity, not elsewhere classified, left ankle M21.079 Valgus deformity, not elsewhere classified, unspecified ankle M21.10 Varus deformity, not elsewhere classified, unspecified site M21.121 Varus deformity, not elsewhere classified, right elbow M21.122 Varus deformity, not elsewhere classified, left elbow M21.129 Varus deformity, not elsewhere classified, unspecified elbow M21.151 Varus deformity, not elsewhere classified, right hip M21.152 Varus deformity, not elsewhere classified, left hip M21.159 Varus deformity, not elsewhere classified, unspecified hip M21.161 Varus deformity, not elsewhere classified, right knee M21.162 Varus deformity, not elsewhere classified, left knee M21.169 Varus deformity, not elsewhere classified, unspecified knee M21.171 Varus deformity, not elsewhere classified, right ankle M21.172 Varus deformity, not elsewhere classified, left ankle M21.179 Varus deformity, not elsewhere classified, unspecified ankle M21.20 Flexion deformity, unspecified site M21.211 Flexion deformity, right shoulder M21.212 Flexion deformity, left shoulder M21.219 Flexion deformity, unspecified shoulder M21.221 Flexion deformity, right elbow M21.222 Flexion deformity, left elbow M21.229 Flexion deformity, unspecified elbow M21.231 Flexion deformity, right wrist M21.232 Flexion deformity, left wrist M21.239 Flexion deformity, unspecified wrist M21.241 Flexion deformity, right finger joints M21.242 Flexion deformity, left finger joints M21.249 Flexion deformity, unspecified finger joints M21.251 Flexion deformity, right hip M21.252 Flexion deformity, left hip M21.259 Flexion deformity, unspecified hip M21.261 Flexion deformity, right knee M21.262 Flexion deformity, left knee M21.269 Flexion deformity, unspecified knee M21.271 Flexion deformity, right ankle and toes M21.272 Flexion deformity, left ankle and toes M21.279 Flexion deformity, unspecified ankle and toes M21.331 Wrist drop, right wrist M21.332 Wrist drop, left wrist M21.339 Wrist drop, unspecified wrist M21.371 Foot drop, right foot M21.372 Foot drop, left foot M21.379 Foot drop, unspecified foot M21.40 Flat foot [pes planus] (acquired), unspecified foot M21.41 Flat foot [pes planus] (acquired), right foot M21.42 Flat foot [pes planus] (acquired), left foot M21.511 Acquired clawhand, right hand M21.512 Acquired clawhand, left hand M21.519 Acquired clawhand, unspecified hand M21.521 Acquired clubhand, right hand M21.522 Acquired clubhand, left hand M21.529 Acquired clubhand, unspecified hand M21.531 Acquired clawfoot, right foot M21.532 Acquired clawfoot, left foot M21.539 Acquired clawfoot, unspecified foot M21.541 Acquired clubfoot, right foot M21.542 Acquired clubfoot, left foot M21.549 Acquired clubfoot, unspecified foot M21.611 Bunion of right foot M21.612 Bunion of left foot M21.619 Bunion of unspecified foot M21.621 Bunionette of right foot M21.622 Bunionette of left foot M21.629 Bunionette of unspecified foot M21.6X1 Other acquired deformities of right foot M21.6X2 Other acquired deformities of left foot M21.6X9 Other acquired deformities of unspecified foot M21.70 Unequal limb length (acquired), unspecified site M21.721 Unequal limb length (acquired), right humerus M21.722 Unequal limb length (acquired), left humerus M21.729 Unequal limb length (acquired), unspecified humerus M21.731 Unequal limb length (acquired), right ulna M21.732 Unequal limb length (acquired), left ulna M21.733 Unequal limb length (acquired), right radius M21.734 Unequal limb length (acquired), left radius M21.739 Unequal limb length (acquired), unspecified ulna and radius M21.751 Unequal limb length (acquired), right femur M21.752 Unequal limb length (acquired), left femur M21.759 Unequal limb length (acquired), unspecified femur M21.761 Unequal limb length (acquired), right tibia M21.762 Unequal limb length (acquired), left tibia M21.763 Unequal limb length (acquired), right fibula M21.764 Unequal limb length (acquired), left fibula M21.769 Unequal limb length (acquired), unspecified tibia and fibula M21.80 Other specified acquired deformities of unspecified limb M21.821 Other specified acquired deformities of right upper arm M21.822 Other specified acquired deformities of left upper arm M21.829 Other specified acquired deformities of unspecified upper arm M21.831 Other specified acquired deformities of right forearm M21.832 Other specified acquired deformities of left forearm M21.839 Other specified acquired deformities of unspecified forearm M21.851 Other specified acquired deformities of right thigh M21.852 Other specified acquired deformities of left thigh M21.859 Other specified acquired deformities of unspecified thigh M21.861 Other specified acquired deformities of right lower leg M21.862 Other specified acquired deformities of left lower leg M21.869 Other specified acquired deformities of unspecified lower leg M21.90 Unspecified acquired deformity of unspecified limb M21.921 Unspecified acquired deformity of right upper arm M21.922 Unspecified acquired deformity of left upper arm M21.929 Unspecified acquired deformity of unspecified upper arm M21.931 Unspecified acquired deformity of right forearm M21.932 Unspecified acquired deformity of left forearm M21.939 Unspecified acquired deformity of unspecified forearm M21.941 Unspecified acquired deformity of hand, right hand M21.942 Unspecified acquired deformity of hand, left hand M21.949 Unspecified acquired deformity of hand, unspecified hand M21.951 Unspecified acquired deformity of right thigh M21.952 Unspecified acquired deformity of left thigh M21.959 Unspecified acquired deformity of unspecified thigh M21.961 Unspecified acquired deformity of right lower leg M21.962 Unspecified acquired deformity of left lower leg M21.969 Unspecified acquired deformity of unspecified lower leg
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Reviewed by Prajwal Shrestha, CPC, CRC
Certified Professional Coder (CPC) and Certified Risk Adjustment Coder (CRC) · AAPC Member ID 01997614 · About · Editorial policy · Content last reviewed: 2025-10-01

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