N13.30 Unspecified hydronephrosis

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

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)

Applies from N13.3 Other and unspecified hydronephrosis

Excludes1 (never code together)

• hydronephrosis with infection (N13.6)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 591 Hydronephrosis (approximate)

Code annotations containing back-references to N13.30

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 N13.30

• Hydronephrosis (atrophic) (early) (functionless) (intermittent) (primary) (secondary) NEC

Nearby codes

• N13 Obstructive and reflux uropathy
• N13.0 Hydronephrosis with ureteropelvic junction obstruction
• 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 (this code)
• N13.39 Other hydronephrosis
• N13.4 Hydroureter
• N13.5 Crossing vessel and stricture of ureter without hydronephrosis
• N13.6 Pyonephrosis
• N13.7 Vesicoureteral-reflux