M20 Acquired deformities of fingers and toes

Category / Non-billable header 46 subcodes

Block: Other joint disorders (M20-M25)

Excludes 1 (cannot be coded together)

  • acquired absence of fingers and toes (Z89.-)
  • congenital absence of fingers and toes (Q71.3-, Q72.3-)
  • congenital deformities and malformations of fingers and toes (Q66.-, Q68-Q70, Q74.-)

Subcodes

Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.

Code Description Billable
M20..0 Deformity of finger(s) No
M20..00 Unspecified deformity of finger(s) No
M20..001 Unspecified deformity of right finger(s) Yes
M20..002 Unspecified deformity of left finger(s) Yes
M20..009 Unspecified deformity of unspecified finger(s) Yes
M20..01 Mallet finger No
M20..011 Mallet finger of right finger(s) Yes
M20..012 Mallet finger of left finger(s) Yes
M20..019 Mallet finger of unspecified finger(s) Yes
M20..02 Boutonniere deformity No
M20..021 Boutonniere deformity of right finger(s) Yes
M20..022 Boutonniere deformity of left finger(s) Yes
M20..029 Boutonniere deformity of unspecified finger(s) Yes
M20..03 Swan-neck deformity No
M20..031 Swan-neck deformity of right finger(s) Yes
M20..032 Swan-neck deformity of left finger(s) Yes
M20..039 Swan-neck deformity of unspecified finger(s) Yes
M20..09 Other deformity of finger(s) No
M20..091 Other deformity of right finger(s) Yes
M20..092 Other deformity of left finger(s) Yes
M20..099 Other deformity of finger(s), unspecified finger(s) Yes
M20..1 Hallux valgus (acquired) No
M20..10 Hallux valgus (acquired), unspecified foot Yes
M20..11 Hallux valgus (acquired), right foot Yes
M20..12 Hallux valgus (acquired), left foot Yes
M20..2 Hallux rigidus No
M20..20 Hallux rigidus, unspecified foot Yes
M20..21 Hallux rigidus, right foot Yes
M20..22 Hallux rigidus, left foot Yes
M20..3 Hallux varus (acquired) No
M20..30 Hallux varus (acquired), unspecified foot Yes
M20..31 Hallux varus (acquired), right foot Yes
M20..32 Hallux varus (acquired), left foot Yes
M20..4 Other hammer toe(s) (acquired) No
M20..40 Other hammer toe(s) (acquired), unspecified foot Yes
M20..41 Other hammer toe(s) (acquired), right foot Yes
M20..42 Other hammer toe(s) (acquired), left foot Yes
M20..5 Other deformities of toe(s) (acquired) No
M20..5X Other deformities of toe(s) (acquired) No
M20..5X1 Other deformities of toe(s) (acquired), right foot Yes
M20..5X2 Other deformities of toe(s) (acquired), left foot Yes
M20..5X9 Other deformities of toe(s) (acquired), unspecified foot Yes
M20..6 Acquired deformities of toe(s), unspecified No
M20..60 Acquired deformities of toe(s), unspecified, unspecified foot Yes
M20..61 Acquired deformities of toe(s), unspecified, right foot Yes
M20..62 Acquired deformities of toe(s), unspecified, left foot Yes

Last reviewed: September 2026