M21 ICD-10-CA category: Other acquired deformities of limbs
M21 isn’t a code on its own. Choose one of the 20 codes beneath it, the one the documentation supports.
Official description
M21Other acquired deformities of limbs
ICD-10-CA · Canada
Codes in M21
M21 isn’t a code on its own. Open the group that matches what the note documents.
M21.0Valgus deformity, not elsewhere classifiedM21.1Varus deformity, not elsewhere classifiedM21.2Flexion deformityM21.3Wrist or foot drop (acquired)M21.4Flat foot [pes planus] (acquired)M21.5Acquired clawhand, clubhand, clawfoot and clubfoot (3 codes)M21.6Other acquired deformities of ankle and footM21.7Unequal limb length (acquired)M21.8Other specified acquired deformities of limbs (9 codes)M21.9Acquired deformity of limb, unspecifiedNotes for M21
As CIHI prints them, with any note M21 takes from the headings above it.
Includes
- Disorders affecting predominantly peripheral (limb) jointsFrom M00-M25 Arthropathies
Excludes
Conditions classified elsewhere.
- Acquired:• absence of limb (Z89.-)• deformities of fingers or toes (M20.-)congenital:• absence of limbs (Q71-Q73)• deformities and malformations of limbs (Q65-Q66)(Q68-Q74)coxa plana (M91.2)
- Joints of the spine (M40-M54)From M20-M25 Other joint disorders
- Certain:• conditions originating in the perinatal period (P00-P96)• disorders of the temporomandibular joint (K07.6)• infectious and parasitic diseases (A00-B99)compartment syndrome (T79.6)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Note
- The following fifth characters represent the following sites of involvement:0 Multiple sites1 Shoulder region: clavical , scapula — joint acromioclavicular, glenohumeral, sternoclavicular2 Upper arm: humerus — elbow joint,3 Forearm: radius , ulna — wrist joint,4 Hand: carpus, fingers, metacarpus — joints between these bones,5 Pelvic region and thigh: buttock , femur , pelvis — joint hip , sacroiliac6 Lower leg: fibula , tibia — knee joint7 Ankle and foot: metatarsus, tarsus, toes — other joints in foot8 Other:head neck ribs skull trunk vertebral column9 Site unspecifiedFrom Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Where M21 sits
- 1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
- 2Block M00-M25Arthropathies
- 3Block M20-M25Other joint disorders
- 4Category M21Other acquired deformities of limbs
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
Is M21 a valid ICD-10-CA code?
No. M21 (Other acquired deformities of limbs) is a category heading in CIHI’s ICD-10-CA FY 2026–2027 release. It holds 20 codes; record the one the documentation supports.
Where is M21 in ICD-10-CA?
M21 sits under M20-M25 Other joint disorders, within M00-M25 Arthropathies, within Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99).
What coding notes apply to M21?
ICD-10-CA lists Excludes, Includes, Note notes for M21, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.