2020 ICD-10-CM Diagnosis Code M21.1

Varus deformity, not elsewhere classified

    2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
  • M21.1 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2020 edition of ICD-10-CM M21.1 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of M21.1 - other international versions of ICD-10 M21.1 may differ.
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as M21.1. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • metatarsus varus (
    ICD-10-CM Diagnosis Code Q66.22

    Congenital metatarsus adductus

      2017 - New Code 2018 2019 2020 - Converted to Parent Code Non-Billable/Non-Specific Code
    Applicable To
    • Congenital metatarsus varus
    Q66.22-
    )
  • tibia vara (
    ICD-10-CM Diagnosis Code M92.5

    Juvenile osteochondrosis of tibia and fibula

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Applicable To
    • Osteochondrosis (juvenile) of proximal tibia [Blount]
    • Osteochondrosis (juvenile) of tibial tubercle [Osgood-Schlatter]
    • Tibia vara
    M92.5
    )
The following code(s) above M21.1 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to M21.1:
  • M00-M99
    2020 ICD-10-CM Range M00-M99

    Diseases of the musculoskeletal system and connective tissue

    Note
    • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
    Type 2 Excludes
    • arthropathic psoriasis (L40.5-)
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • compartment syndrome (traumatic) (T79.A-)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the musculoskeletal system and connective tissue
  • M20-M25
    2020 ICD-10-CM Range M20-M25

    Other joint disorders

    Type 2 Excludes
    Other joint disorders
  • M21
    ICD-10-CM Diagnosis Code M21

    Other acquired deformities of limbs

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • acquired absence of limb (Z89.-)
    • congenital absence of limbs (Q71-Q73)
    • congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74)
    Type 2 Excludes
    • acquired deformities of fingers or toes (M20.-)
    • coxa plana (M91.2)
    Other acquired deformities of limbs
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
Code annotations containing back-references to M21.1:
  • Type 1 Excludes: Q66
    ICD-10-CM Diagnosis Code Q66

    Congenital deformities of feet

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • reduction defects of feet (Q72.-)
    • valgus deformities (acquired) (M21.0-)
    • varus deformities (acquired) (M21.1-)

Diagnosis Index entries containing back-references to M21.1:

ICD-10-CM Codes Adjacent To M21.1
M21.052 Valgus deformity, not elsewhere classified, left hip
M21.059 Valgus deformity, not elsewhere classified, unspecified hip
M21.06 Valgus deformity, not elsewhere classified, knee
M21.061 Valgus deformity, not elsewhere classified, right knee
M21.062 Valgus deformity, not elsewhere classified, left knee
M21.069 Valgus deformity, not elsewhere classified, unspecified knee
M21.07 Valgus deformity, not elsewhere classified, ankle
M21.071 Valgus deformity, not elsewhere classified, right ankle
M21.072 Valgus deformity, not elsewhere classified, left ankle
M21.079 Valgus deformity, not elsewhere classified, unspecified ankle
M21.1 Varus deformity, not elsewhere classified
M21.10 …… unspecified site
M21.12 Varus deformity, not elsewhere classified, elbow
M21.121 Varus deformity, not elsewhere classified, right elbow
M21.122 Varus deformity, not elsewhere classified, left elbow
M21.129 Varus deformity, not elsewhere classified, unspecified elbow
M21.15 Varus deformity, not elsewhere classified, hip
M21.151 Varus deformity, not elsewhere classified, right hip
M21.152 Varus deformity, not elsewhere classified, left hip
M21.159 Varus deformity, not elsewhere classified, unspecified
M21.16 Varus deformity, not elsewhere classified, knee

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.