N13.4 Hydroureter

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Excludes1 (never code together)

• congenital hydroureter (Q62.3-)
• hydroureter with infection (N13.6)
• vesicoureteral-reflux with hydroureter (N13.73-)

Applies from N13 Obstructive and reflux uropathy

Excludes2 (not included here)

• calculus of kidney and ureter without hydronephrosis (N20.-)
• congenital obstructive defects of renal pelvis and ureter (Q62.0-Q62.3)
• hydronephrosis with ureteropelvic junction obstruction (Q62.11)
• obstructive pyelonephritis (N11.1)

MS-DRG index

Defines the logic of DRG(s) 693-694 in MDC 11.

Approximate ICD-9-CM (GEMs)

• 593.5 Hydroureter

Code annotations containing back-references to N13.4

Back-references to N13.4

• Type 1 Excludes: N28.8 Other specified disorders of kidney and ureter ("hydroureter (N13.4)")

Back-references to N13

• Type 1 Excludes: N11.1 Chronic obstructive pyelonephritis ("obstructive uropathy (N13.-)")
• Code Also: N80.A4 Superficial endometriosis of ureter (", if applicable, obstructive and reflux uropathy (N13.-)")
• Code Also: N80.A5 Deep endometriosis of ureter (", if applicable, obstructive and reflux uropathy (N13.-)")
• Code Also: N80.A6 Endometriosis of ureter, unspecified depth (", if applicable, obstructive and reflux uropathy (N13.-)")

Diagnosis Index entries for N13.4

• Dilatation › ureter (idiopathic) › due to obstruction
• Hydroureter

Nearby codes

• N13.1 Hydronephrosis with ureteral stricture, not elsewhere classified
• N13.2 Hydronephrosis with renal and ureteral calculous obstruction
• N13.3 Other and unspecified hydronephrosis
• N13.30 Unspecified hydronephrosis
• N13.39 Other hydronephrosis
• N13.4 Hydroureter (this code)
• N13.5 Crossing vessel and stricture of ureter without hydronephrosis
• N13.6 Pyonephrosis
• N13.7 Vesicoureteral-reflux
• N13.70 Vesicoureteral-reflux, unspecified
• N13.71 Vesicoureteral-reflux without reflux nephropathy