ICD-10-CM 2027 diagnosis code
M21.76Unequal limb length (acquired), tibia and fibula
M21.76 is a header code, so it can't be reported by itself. Choose one of the 5 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M21.76
M21.76 is the ICD-10-CM diagnosis code for unequal limb length (acquired), tibia and fibula. It belongs to category M21 (other acquired deformities of limbs), block M20-M25 (other joint disorders) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.
Within M21.7 (unequal limb length (acquired)), M21.76 is specifically for unequal limb length (acquired), tibia and fibula. Related codes cover unspecified site (M21.70), humerus (M21.72), ulna and radius (M21.73) and femur (M21.75).
To report this condition, pick the subcode that matches the documentation: M21.761 (tibia), M21.762 (tibia), M21.763 (fibula), M21.764 (fibula) and M21.769 (fibula).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under M21.76
- M21.761Unequal limb length (acquired), right tibiaBillable
- M21.762Unequal limb length (acquired), left tibiaBillable
- M21.763Unequal limb length (acquired), right fibulaBillable
- M21.764Unequal limb length (acquired), left fibulaBillable
- M21.769Unequal limb length (acquired), unspecified tibia and fibulaBillable
Notes that apply from higher levels
Instructions written at a parent level also apply to M21.76.
› From M21.7 Unequal limb length (acquired)
- The site used should correspond to the shorter limb
Broader instructions also apply from M20-M25 Other joint disorders and Chapter 13: Diseases of the musculoskeletal system and connective tissue.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to M21.76.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about M21.76
Is M21.76 billable?
- No. M21.76 is a header code. Report one of its more specific subcodes instead.