Alphabetic Index · main term
Fallen arches
Fallen arches is a main term in the FY2027 ICD-10-CM Alphabetic Index (Index to Diseases and Injuries). It is a cross-reference: the Index sends you to Deformity, limb, flat foot, which lists M21.4-. Confirm the code in the Tabular List before you report it.
Where the Index sends you
see Deformity, limb (acquired), flat foot
Flat foot [pes planus] (acquired)