M21.8 – Other specified acquired deformities of limbs
ICD-10-CM 2027 diagnosis code · Other joint disorders
ICD-10-CM code
M21.8
- Code
M21.8(claims format:M218)- Description
- Other specified acquired deformities of limbs
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
- Block
- M20-M25 Other joint disorders
- Parent codes
- M21
Billable codes under M21.8
M21.8 is a header code and cannot be used on claims. Choose the most specific code:
- M21.80 – Other specified acquired deformities of unspecified limbBillable
- M21.82 – Other specified acquired deformities of upper armHeader (more codes below)
- M21.83 – Other specified acquired deformities of forearmHeader (more codes below)
- M21.85 – Other specified acquired deformities of thighHeader (more codes below)
- M21.86 – Other specified acquired deformities of lower legHeader (more codes below)
Notes for M21.8
Excludes2 (not included here):
- coxa plana (M91.2)
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
M21 – Other acquired deformities of limbs
Excludes1 (not coded here):
Block M20-M25
Related codes in M21
- M21.0 – Valgus deformity, not elsewhere classifiedHeader
- M21.1 – Varus deformity, not elsewhere classifiedHeader
- M21.2 – Flexion deformityHeader
- M21.3 – Wrist or foot drop (acquired)Header
- M21.4 – Flat foot [pes planus] (acquired)Header
- M21.5 – Acquired clawhand, clubhand, clawfoot and clubfootHeader
- M21.6 – Other acquired deformities of footHeader
- M21.7 – Unequal limb length (acquired)Header
- M21.9 – Unspecified acquired deformity of limb and handHeader
Frequently asked questions
What is ICD-10 code M21.8?
M21.8 is the ICD-10-CM code for other specified acquired deformities of limbs, in the block M20-M25 (Other joint disorders).
Is M21.8 a billable code?
No. M21.8 is a header code with more specific child codes; report one of the billable codes listed above.
What category does M21.8 belong to?
It belongs to category M21 – Other acquired deformities of limbs.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.