M21 Other acquired deformities of limbs

Category / Non-billable header 171 subcodes

Block: Other joint disorders (M20-M25)

Excludes 1 (cannot be coded together)

  • acquired absence of limb (Z89.-)
  • congenital absence of limbs (Q71-Q73)
  • congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74)

Excludes 2 (not included here)

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

Subcodes

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

Code Description Billable
M21..0 Valgus deformity, not elsewhere classified No
M21..00 Valgus deformity, not elsewhere classified, unspecified site Yes
M21..02 Valgus deformity, not elsewhere classified, elbow No
M21..021 Valgus deformity, not elsewhere classified, right elbow Yes
M21..022 Valgus deformity, not elsewhere classified, left elbow Yes
M21..029 Valgus deformity, not elsewhere classified, unspecified elbow Yes
M21..05 Valgus deformity, not elsewhere classified, hip No
M21..051 Valgus deformity, not elsewhere classified, right hip Yes
M21..052 Valgus deformity, not elsewhere classified, left hip Yes
M21..059 Valgus deformity, not elsewhere classified, unspecified hip Yes
M21..06 Valgus deformity, not elsewhere classified, knee No
M21..061 Valgus deformity, not elsewhere classified, right knee Yes
M21..062 Valgus deformity, not elsewhere classified, left knee Yes
M21..069 Valgus deformity, not elsewhere classified, unspecified knee Yes
M21..07 Valgus deformity, not elsewhere classified, ankle No
M21..071 Valgus deformity, not elsewhere classified, right ankle Yes
M21..072 Valgus deformity, not elsewhere classified, left ankle Yes
M21..079 Valgus deformity, not elsewhere classified, unspecified ankle Yes
M21..1 Varus deformity, not elsewhere classified No
M21..10 Varus deformity, not elsewhere classified, unspecified site Yes
M21..12 Varus deformity, not elsewhere classified, elbow No
M21..121 Varus deformity, not elsewhere classified, right elbow Yes
M21..122 Varus deformity, not elsewhere classified, left elbow Yes
M21..129 Varus deformity, not elsewhere classified, unspecified elbow Yes
M21..15 Varus deformity, not elsewhere classified, hip No
M21..151 Varus deformity, not elsewhere classified, right hip Yes
M21..152 Varus deformity, not elsewhere classified, left hip Yes
M21..159 Varus deformity, not elsewhere classified, unspecified hip Yes
M21..16 Varus deformity, not elsewhere classified, knee No
M21..161 Varus deformity, not elsewhere classified, right knee Yes
M21..162 Varus deformity, not elsewhere classified, left knee Yes
M21..169 Varus deformity, not elsewhere classified, unspecified knee Yes
M21..17 Varus deformity, not elsewhere classified, ankle No
M21..171 Varus deformity, not elsewhere classified, right ankle Yes
M21..172 Varus deformity, not elsewhere classified, left ankle Yes
M21..179 Varus deformity, not elsewhere classified, unspecified ankle Yes
M21..2 Flexion deformity No
M21..20 Flexion deformity, unspecified site Yes
M21..21 Flexion deformity, shoulder No
M21..211 Flexion deformity, right shoulder Yes
M21..212 Flexion deformity, left shoulder Yes
M21..219 Flexion deformity, unspecified shoulder Yes
M21..22 Flexion deformity, elbow No
M21..221 Flexion deformity, right elbow Yes
M21..222 Flexion deformity, left elbow Yes
M21..229 Flexion deformity, unspecified elbow Yes
M21..23 Flexion deformity, wrist No
M21..231 Flexion deformity, right wrist Yes
M21..232 Flexion deformity, left wrist Yes
M21..239 Flexion deformity, unspecified wrist Yes
M21..24 Flexion deformity, finger joints No
M21..241 Flexion deformity, right finger joints Yes
M21..242 Flexion deformity, left finger joints Yes
M21..249 Flexion deformity, unspecified finger joints Yes
M21..25 Flexion deformity, hip No
M21..251 Flexion deformity, right hip Yes
M21..252 Flexion deformity, left hip Yes
M21..259 Flexion deformity, unspecified hip Yes
M21..26 Flexion deformity, knee No
M21..261 Flexion deformity, right knee Yes
M21..262 Flexion deformity, left knee Yes
M21..269 Flexion deformity, unspecified knee Yes
M21..27 Flexion deformity, ankle and toes No
M21..271 Flexion deformity, right ankle and toes Yes
M21..272 Flexion deformity, left ankle and toes Yes
M21..279 Flexion deformity, unspecified ankle and toes Yes
M21..3 Wrist or foot drop (acquired) No
M21..33 Wrist drop (acquired) No
M21..331 Wrist drop, right wrist Yes
M21..332 Wrist drop, left wrist Yes
M21..339 Wrist drop, unspecified wrist Yes
M21..37 Foot drop (acquired) No
M21..371 Foot drop, right foot Yes
M21..372 Foot drop, left foot Yes
M21..379 Foot drop, unspecified foot Yes
M21..4 Flat foot [pes planus] (acquired) No
M21..40 Flat foot [pes planus] (acquired), unspecified foot Yes
M21..41 Flat foot [pes planus] (acquired), right foot Yes
M21..42 Flat foot [pes planus] (acquired), left foot Yes
M21..5 Acquired clawhand, clubhand, clawfoot and clubfoot No
M21..51 Acquired clawhand No
M21..511 Acquired clawhand, right hand Yes
M21..512 Acquired clawhand, left hand Yes
M21..519 Acquired clawhand, unspecified hand Yes
M21..52 Acquired clubhand No
M21..521 Acquired clubhand, right hand Yes
M21..522 Acquired clubhand, left hand Yes
M21..529 Acquired clubhand, unspecified hand Yes
M21..53 Acquired clawfoot No
M21..531 Acquired clawfoot, right foot Yes
M21..532 Acquired clawfoot, left foot Yes
M21..539 Acquired clawfoot, unspecified foot Yes
M21..54 Acquired clubfoot No
M21..541 Acquired clubfoot, right foot Yes
M21..542 Acquired clubfoot, left foot Yes
M21..549 Acquired clubfoot, unspecified foot Yes
M21..6 Other acquired deformities of foot No
M21..61 Bunion No
M21..611 Bunion of right foot Yes
M21..612 Bunion of left foot Yes
M21..619 Bunion of unspecified foot Yes
M21..62 Bunionette No
M21..621 Bunionette of right foot Yes
M21..622 Bunionette of left foot Yes
M21..629 Bunionette of unspecified foot Yes
M21..6X Other acquired deformities of foot No
M21..6X1 Other acquired deformities of right foot Yes
M21..6X2 Other acquired deformities of left foot Yes
M21..6X9 Other acquired deformities of unspecified foot Yes
M21..7 Unequal limb length (acquired) No
M21..70 Unequal limb length (acquired), unspecified site Yes
M21..72 Unequal limb length (acquired), humerus No
M21..721 Unequal limb length (acquired), right humerus Yes
M21..722 Unequal limb length (acquired), left humerus Yes
M21..729 Unequal limb length (acquired), unspecified humerus Yes
M21..73 Unequal limb length (acquired), ulna and radius No
M21..731 Unequal limb length (acquired), right ulna Yes
M21..732 Unequal limb length (acquired), left ulna Yes
M21..733 Unequal limb length (acquired), right radius Yes
M21..734 Unequal limb length (acquired), left radius Yes
M21..739 Unequal limb length (acquired), unspecified ulna and radius Yes
M21..75 Unequal limb length (acquired), femur No
M21..751 Unequal limb length (acquired), right femur Yes
M21..752 Unequal limb length (acquired), left femur Yes
M21..759 Unequal limb length (acquired), unspecified femur Yes
M21..76 Unequal limb length (acquired), tibia and fibula No
M21..761 Unequal limb length (acquired), right tibia Yes
M21..762 Unequal limb length (acquired), left tibia Yes
M21..763 Unequal limb length (acquired), right fibula Yes
M21..764 Unequal limb length (acquired), left fibula Yes
M21..769 Unequal limb length (acquired), unspecified tibia and fibula Yes
M21..8 Other specified acquired deformities of limbs No
M21..80 Other specified acquired deformities of unspecified limb Yes
M21..82 Other specified acquired deformities of upper arm No
M21..821 Other specified acquired deformities of right upper arm Yes
M21..822 Other specified acquired deformities of left upper arm Yes
M21..829 Other specified acquired deformities of unspecified upper arm Yes
M21..83 Other specified acquired deformities of forearm No
M21..831 Other specified acquired deformities of right forearm Yes
M21..832 Other specified acquired deformities of left forearm Yes
M21..839 Other specified acquired deformities of unspecified forearm Yes
M21..85 Other specified acquired deformities of thigh No
M21..851 Other specified acquired deformities of right thigh Yes
M21..852 Other specified acquired deformities of left thigh Yes
M21..859 Other specified acquired deformities of unspecified thigh Yes
M21..86 Other specified acquired deformities of lower leg No
M21..861 Other specified acquired deformities of right lower leg Yes
M21..862 Other specified acquired deformities of left lower leg Yes
M21..869 Other specified acquired deformities of unspecified lower leg Yes
M21..9 Unspecified acquired deformity of limb and hand No
M21..90 Unspecified acquired deformity of unspecified limb Yes
M21..92 Unspecified acquired deformity of upper arm No
M21..921 Unspecified acquired deformity of right upper arm Yes
M21..922 Unspecified acquired deformity of left upper arm Yes
M21..929 Unspecified acquired deformity of unspecified upper arm Yes
M21..93 Unspecified acquired deformity of forearm No
M21..931 Unspecified acquired deformity of right forearm Yes
M21..932 Unspecified acquired deformity of left forearm Yes
M21..939 Unspecified acquired deformity of unspecified forearm Yes
M21..94 Unspecified acquired deformity of hand No
M21..941 Unspecified acquired deformity of hand, right hand Yes
M21..942 Unspecified acquired deformity of hand, left hand Yes
M21..949 Unspecified acquired deformity of hand, unspecified hand Yes
M21..95 Unspecified acquired deformity of thigh No
M21..951 Unspecified acquired deformity of right thigh Yes
M21..952 Unspecified acquired deformity of left thigh Yes
M21..959 Unspecified acquired deformity of unspecified thigh Yes
M21..96 Unspecified acquired deformity of lower leg No
M21..961 Unspecified acquired deformity of right lower leg Yes
M21..962 Unspecified acquired deformity of left lower leg Yes
M21..969 Unspecified acquired deformity of unspecified lower leg Yes

Last reviewed: September 2026