N11.1 vs N13
N11.1 (Chronic obstructive pyelonephritis) compared with N13 (Obstructive and reflux uropathy), 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 N13: “obstructive uropathy (N13.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Yes, when both are documented. N13 carries an Excludes2 note covering N11.1: “obstructive pyelonephritis (N11.1)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| N11.1Chronic obstructive pyelonephritis | N13Obstructive and reflux uropathy | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| 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). | Obstructive and reflux uropathy is a non-billable ICD-10-CM category code (N13). |
| Includes | chronic infectious interstitial nephritis chronic pyelitis chronic pyelonephritis 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