M21.1 — Varus deformity, not elsewhere classified
Is M21.1 billable?
No — M21.1 is a non-billable header code. M21.1 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 13 billable codes beneath M21.1.
Billable codes under this header
- M21.10Varus deformity, not elsewhere classified, unspecified site
- 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
M21.1 at a glance
| Code | M21.1 |
|---|---|
| Description | Varus deformity, not elsewhere classified |
| 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 M21.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes1 — never code together — inherited from M21
The conditions below can never be reported together with M21.1 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 — inherited from Chapter 13
The conditions below are not part of M21.1, but a patient may have both at the same time. When documentation supports it, M21.1 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 M21.1, but a patient may have both at the same time. When documentation supports it, M21.1 and the excluded code may both be reported.
- joints of the spine (M40-M54)
Excludes2 — not included here — inherited from M21
The conditions below are not part of M21.1, but a patient may have both at the same time. When documentation supports it, M21.1 and the excluded code may both be reported.
What codes fall under M21.1? (5)
- M21.10Varus deformity, not elsewhere classified, unspecified site
- M21.12Varus deformity, not elsewhere classified, elbownot billable
- M21.15Varus deformity, not elsewhere classified, hipnot billable
- M21.16Varus deformity, not elsewhere classified, kneenot billable
- M21.17Varus deformity, not elsewhere classified, anklenot billable
How long has M21.1 existed?
M21.1 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.
What other codes are in the M21 family? (9)
- M21.0Valgus 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