N20.9 vs N21.9
N20.9 (Urinary calculus, unspecified) compared with N21.9 (Calculus of lower urinary tract, unspecified), 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. N21.9 carries an Excludes1 note covering N20.9: “calculus of urinary tract NOS (N20.9)”
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
| N20.9Urinary calculus, unspecified | N21.9Calculus of lower urinary tract, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | N00-N99 — Diseases of the Genitourinary System (N00-N99) | N00-N99 — Diseases of the Genitourinary System (N00-N99) |
| Definition | Urinary calculus, unspecified is a billable ICD-10-CM diagnosis code (N20.9). | Calculus of lower urinary tract, unspecified is a billable ICD-10-CM diagnosis code (N21.9). |
| Includes | — | calculus of lower urinary tract with cystitis and urethritis |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources