M20.029 (Boutonnière deformity of unspecified finger(s)) compared with Z89 (Acquired absence of limb), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Not coded here — these two are mutually exclusive.
“acquired absence of fingers and toes (Z89.-)”
An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.
Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a
No — do not report together. M20.029 carries an Excludes1 note covering Z89: “acquired absence of fingers and toes (Z89.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
| M20.029Boutonnière deformity of unspecified finger(s) | Z89Acquired absence of limb | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | Boutonnière deformity of unspecified finger(s) is a billable ICD-10-CM diagnosis code (M20.029). | Acquired absence of limb is a non-billable ICD-10-CM category code (Z89). |
| Includes | — | amputation status postprocedural loss of limb post-traumatic loss of limb |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources