M21.37 Foot drop (acquired)

Non-billable header with 3 child codes.

Applies from M21 Other acquired deformities of limbs

Excludes1 (never code together)

• 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)

• acquired deformities of fingers or toes (M20.-)
• coxa plana (M91.2)

Codes under M21.37

• M21.371 Foot drop, right foot
• M21.372 Foot drop, left foot
• M21.379 Foot drop, unspecified foot

Code annotations containing back-references to M21.37

Back-references to M21

• Type 1 Excludes: M23 Internal derangement of knee ("deformity of knee (M21.-)")
• Type 2 Excludes: M24.5 Contracture of joint ("acquired deformities of limbs (M20-M21)")
• Type 2 Excludes: M25 Other joint disorder, not elsewhere classified ("acquired deformities of limb (M20-M21)")
• Type 2 Excludes: M95 Other acquired deformities of musculoskeletal system and connective tissue ("acquired deformities of limbs (M20-M21)")
• Type 1 Excludes: Z89 Acquired absence of limb ("acquired deformities of limbs (M20-M21)")

Diagnosis Index entries for M21.37

• Deformity › limb (acquired) › foot › drop

Nearby codes

• M21.3 Wrist or foot drop (acquired)
• M21.33 Wrist drop (acquired)
• M21.331 Wrist drop, right wrist
• M21.332 Wrist drop, left wrist
• M21.339 Wrist drop, unspecified wrist
• M21.37 Foot drop (acquired) (this code)
• M21.371 Foot drop, right foot
• M21.372 Foot drop, left foot
• M21.379 Foot drop, unspecified foot
• M21.4 Flat foot [pes planus] (acquired)
• M21.40 Flat foot [pes planus] (acquired), unspecified foot