ICD-10-CM 2027
ICD-10 code for Pyelonephrosis
From the official ICD-10-CM alphabetic index entry “Pyelonephrosis (obstructive)”. Page updated September 29, 2026.
About coding Pyelonephrosis
The ICD-10-CM code for Pyelonephrosis is N11.1 (Chronic obstructive pyelonephritis). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on N11.1.
Within N11 (chronic tubulo-interstitial nephritis), N11.1 is specifically for chronic obstructive pyelonephritis. Related codes cover nonobstructive reflux-associated chronic pyelonephritis (N11.0), other chronic tubulo-interstitial nephritis (N11.8) and unspecified (N11.9).
Don't report N11.1 together with the conditions in its Excludes1 note: calculous pyelonephritis (N20.9) and obstructive uropathy (N13.-).
Use an additional code (B95-B97), to identify infectious agent.
More specific Pyelonephrosis codes (official index)
- chronic N11.9 — Chronic tubulo-interstitial nephritis, unspecified
Don't confuse with (Excludes1 for N11.1)
Common questions about Pyelonephrosis ICD-10 codes
What is the ICD-10 code for Pyelonephrosis?
- N11.1 — Chronic obstructive pyelonephritis. More specific codes apply when the documentation supports them: N11.9.
What is the ICD-10 code for chronic pyelonephrosis?
- N11.9 — Chronic tubulo-interstitial nephritis, unspecified.
Is N11.1 billable?
- Yes. N11.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can N11.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict N11.1 as a principal diagnosis.
Is N11.1 a CC or MCC?
- N11.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.