N13.6 Pyonephrosis
The ICD-10-CM code for Pyonephrosis is N13.6 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- N10-N16: Renal tubulo-interstitial diseases (N10-N16)
- Category N13
- 23 codes (18 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to N13.6:
- Pyohydronephrosis
- Pyonephrosis
- Hydropyonephrosis
- Hydroureter › with infection
- Ormond's disease (with ureteral obstruction) › with infection
- Calculus, calculi, calculous › pyelitis (impacted) (recurrent) › with hydronephrosis
- Angulation › ureter › with infection
- Calculus, calculi, calculous › pyelonephritis (impacted) (recurrent) › with hydronephrosis
Inclusion Terms
- Conditions in N13.0-N13.5 with infection
- Obstructive uropathy with infection
U.S. Hospital Utilization
- An estimated 348,810 U.S. inpatient stays in 2023 included N13.6 among the documented diagnoses.
- 95,910 stays listed it as the principal diagnosis.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
CKD staging and code assignment (N18.-)The ICD-10-CM classifies CKD based on severity. The severity of CKD is designated by stages 1-5. Stage 2, code N18.2, equates to mild CKD; stage 3, codes N18.30-N18.32, equate to moderate CKD; and stage 4, code N18.4, equates to severe CKD. Code N18.6, End stage renal disease (ESRD), is assigned when the provider has documented end- stage renal disease (ESRD).
CKD stage plus ESRD: assign N18.6 onlyIf both a stage of CKD and ESRD are documented, assign code N18.6 only.
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026