N26 vs N27
N26 (Unspecified contracted kidney) compared with N27 (Small kidney of unknown cause), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. N26 carries an Excludes1 note covering N27: “small kidney of unknown cause (N27.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| N26Unspecified contracted kidney | N27Small kidney of unknown cause | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | N00-N99 — Diseases of the Genitourinary System (N00-N99) | N00-N99 — Diseases of the Genitourinary System (N00-N99) |
| Definition | Unspecified contracted kidney is a non-billable ICD-10-CM category code (N26). | Small kidney of unknown cause is a non-billable ICD-10-CM category code (N27). |
| Includes | — | oligonephronia |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources