N11.1 vs N20.9
N11.1 (Chronic obstructive pyelonephritis) compared with N20.9 (Urinary calculus, 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. N11.1 carries an Excludes1 note covering N20.9: “calculous pyelonephritis (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
| N11.1Chronic obstructive pyelonephritis | N20.9Urinary calculus, 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 | Chronic obstructive pyelonephritis is a billable ICD-10-CM diagnosis code (N11.1). | Urinary calculus, unspecified is a billable ICD-10-CM diagnosis code (N20.9). |
| Includes | chronic infectious interstitial nephritis chronic pyelitis chronic pyelonephritis pyelonephritis | — |
| Use additional code | code (B95-B97), to identify infectious agent. | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources