M21 — Other acquired deformities of limbs
Not billable
Is M21 billable?
No — M21 is a non-billable header code. M21 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 60 billable codes beneath M21.
Billable codes under this header
- M21.00Valgus deformity, not elsewhere classified, unspecified site
- M21.10Varus deformity, not elsewhere classified, unspecified site
- M21.20Flexion deformity, unspecified site
- M21.40Flat foot [pes planus] (acquired), unspecified foot
- M21.41Flat foot [pes planus] (acquired), right foot
- M21.42Flat foot [pes planus] (acquired), left foot
- M21.70Unequal limb length (acquired), unspecified site
- M21.80Other specified acquired deformities of unspecified limb
- M21.90Unspecified acquired deformity of unspecified limb
- M21.021Valgus deformity, not elsewhere classified, right elbow
- M21.022Valgus deformity, not elsewhere classified, left elbow
- M21.029Valgus deformity, not elsewhere classified, unspecified elbow
- M21.051Valgus deformity, not elsewhere classified, right hip
- M21.052Valgus deformity, not elsewhere classified, left hip
- M21.059Valgus deformity, not elsewhere classified, unspecified hip
- M21.061Valgus deformity, not elsewhere classified, right knee
- M21.062Valgus deformity, not elsewhere classified, left knee
- M21.069Valgus deformity, not elsewhere classified, unspecified knee
- M21.071Valgus deformity, not elsewhere classified, right ankle
- M21.072Valgus deformity, not elsewhere classified, left ankle
- M21.079Valgus deformity, not elsewhere classified, unspecified ankle
- M21.121Varus deformity, not elsewhere classified, right elbow
- M21.122Varus deformity, not elsewhere classified, left elbow
- M21.129Varus deformity, not elsewhere classified, unspecified elbow
- M21.151Varus deformity, not elsewhere classified, right hip
- M21.152Varus deformity, not elsewhere classified, left hip
- M21.159Varus deformity, not elsewhere classified, unspecified hip
- M21.161Varus deformity, not elsewhere classified, right knee
- M21.162Varus deformity, not elsewhere classified, left knee
- M21.169Varus deformity, not elsewhere classified, unspecified knee
- M21.171Varus deformity, not elsewhere classified, right ankle
- M21.172Varus deformity, not elsewhere classified, left ankle
- M21.179Varus deformity, not elsewhere classified, unspecified ankle
- M21.211Flexion deformity, right shoulder
- M21.212Flexion deformity, left shoulder
- M21.219Flexion deformity, unspecified shoulder
- M21.221Flexion deformity, right elbow
- M21.222Flexion deformity, left elbow
- M21.229Flexion deformity, unspecified elbow
- M21.231Flexion deformity, right wrist
- M21.232Flexion deformity, left wrist
- M21.239Flexion deformity, unspecified wrist
- M21.241Flexion deformity, right finger joints
- M21.242Flexion deformity, left finger joints
- M21.249Flexion deformity, unspecified finger joints
- M21.251Flexion deformity, right hip
- M21.252Flexion deformity, left hip
- M21.259Flexion deformity, unspecified hip
- M21.261Flexion deformity, right knee
- M21.262Flexion deformity, left knee
- M21.269Flexion deformity, unspecified knee
- M21.271Flexion deformity, right ankle and toes
- M21.272Flexion deformity, left ankle and toes
- M21.279Flexion deformity, unspecified ankle and toes
- M21.331Wrist drop, right wrist
- M21.332Wrist drop, left wrist
- M21.339Wrist drop, unspecified wrist
- M21.371Foot drop, right foot
- M21.372Foot drop, left foot
- M21.379Foot drop, unspecified foot
M21 at a glance
| Code | M21 |
|---|---|
| Description | Other acquired deformities of limbs |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with M21 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here
The conditions below are not part of M21, but a patient may have both at the same time. When documentation supports it, M21 and the excluded code may both be reported.
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M21, but a patient may have both at the same time. When documentation supports it, M21 and the excluded code may both be reported.
- 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)
Excludes2 — not included here — inherited from M20-M25
The conditions below are not part of M21, but a patient may have both at the same time. When documentation supports it, M21 and the excluded code may both be reported.
- joints of the spine (M40-M54)
What codes fall under M21? (10)
- M21.0Valgus deformity, not elsewhere classifiednot billable
- M21.1Varus deformity, not elsewhere classifiednot billable
- M21.2Flexion deformitynot billable
- M21.3Wrist or foot drop (acquired)not billable
- M21.4Flat foot [pes planus] (acquired)not billable
- M21.5Acquired clawhand, clubhand, clawfoot and clubfootnot billable
- M21.6Other acquired deformities of footnot billable
- M21.7Unequal limb length (acquired)not billable
- M21.8Other specified acquired deformities of limbsnot billable
- M21.9Unspecified acquired deformity of limb and handnot billable
How long has M21 existed?
M21 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.