N13.6
Pyonephrosis
N13.6 (also written N136) is a billable ICD-10-CM diagnosis code for pyonephrosis. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 18 codes in category N13 (Obstructive and reflux uropathy). The Alphabetic Index lists it under 37 entries. Its coding notes include a Use additional code instruction, 1 Excludes1 entry and 12 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
- code (B95-B97), to identify infectious agent.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Gastrointestinal tract and Genitourinary system clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 226 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CHAC
On the CMS list of hospital-acquired conditions (HAC 06: Catheter-Associated Urinary Tract Infection (UTI)). When the claim reports it with a present-on-admission (POA) indicator of N (not present) or U (documentation insufficient), CMS does not pay the CC or MCC DRG for it. A POA of Y (present) or W (clinically undetermined) is paid normally.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix I; CMS Hospital-Acquired Conditions (HAC) Coding page, POA indicator payment tableIncludes
Further defines or gives examples of the content of the category.
Also from chapter/block level (1 note)
- pyelonephritis
Inclusion terms
Conditions classified to this code.
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 37 entries
- Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), kidney, with calculus, with hydronephrosis
- Angulation, ureter, with infection
- Calculus, calculi, calculous, kidney (impacted) (multiple) (pelvis) (recurrent) (staghorn), congenital, with hydronephrosis, with infection
- Calculus, calculi, calculous, kidney (impacted) (multiple) (pelvis) (recurrent) (staghorn), with calculus, ureter, with hydronephrosis, with infection
- Calculus, calculi, calculous, pyelitis (impacted) (recurrent), with hydronephrosis
- Calculus, calculi, calculous, pyelonephritis (impacted) (recurrent), with hydronephrosis
- Calculus, calculi, calculous, ureter (impacted) (recurrent), with calculus, kidney, with hydronephrosis, with infection
- Calculus, calculi, calculous, ureter (impacted) (recurrent), with hydronephrosis, with infection
- Calculus, calculi, calculous, urinary (duct) (impacted) (passage) (tract), with hydronephrosis, with infection
- Constriction, ureter, with infection
- Contraction (s), contracture, contracted, ureterovesical orifice (postinfectional), with infection
- Fasciitis, perirenal (with ureteral obstruction), with infection
Show 25 more
- Fibrosis, fibrotic, retroperitoneal, with infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, obstruction (by) (of), renal calculus, with infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, obstruction (by) (of), ureteral NEC, calculus, with infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, obstruction (by) (of), ureteral NEC, with infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, obstruction (by) (of), ureteropelvic junction (congenital), acquired, with infection
- Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC, with, ureteral stricture NEC, with infection
- Hydropyonephrosis
- Hydroureter, with infection
- Infection, infected, infective (opportunistic), kidney (cortex) (hematogenous), with calculus, with hydronephrosis
- Kink, kinking, ureter (pelvic junction), with, hydronephrosis, with infection
- Narrowing, ureter, with infection
- Obliteration, ureter, with infection
- Obstruction, obstructed, obstructive, ureter (functional) (pelvic junction) NEC, with, hydronephrosis, with infection
- Ormond's disease (with ureteral obstruction), with infection
- Prolapse, prolapsed, ureter, with obstruction, with infection
- Pyelitis (congenital) (uremic), chronic, with calculus, with hydronephrosis
- Pyelitis (congenital) (uremic), with, calculus, with hydronephrosis
- Pyelonephritis, calculous, with hydronephrosis
- Pyelonephritis, chronic, with calculus, with hydronephrosis
- Pyelonephritis, with, calculus, with hydronephrosis
- Pyohydronephrosis
- Pyonephrosis
- Stricture, ureter (postoperative), with, hydronephrosis, with infection
- Stricture, ureterovesical orifice, with infection