Obstructive and reflux uropathy (N13) ICD-10-CM
The N13 code range covers obstructive and reflux uropathy with 23 ICD-10-CM diagnosis codes. 18 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Codes in the N13 Range 23 codes · 18 billable
- N13 Obstructive and reflux uropathyNon-billable
- 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 hydronephrosisNon-billable
- N13.30 Unspecified hydronephrosis
- N13.39 Other hydronephrosis
- N13.4 Hydroureter
- N13.5 Crossing vessel and stricture of ureter without hydronephrosis
- N13.6 Pyonephrosis
- N13.7 Vesicoureteral-refluxNon-billable
- N13.70 Vesicoureteral-reflux, unspecified
- N13.71 Vesicoureteral-reflux without reflux nephropathy
- N13.72 Vesicoureteral-reflux with reflux nephropathy without hydroureterNon-billable
- N13.721 Vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral
- N13.722 Vesicoureteral-reflux with reflux nephropathy without hydroureter, bilateral
- N13.729 Vesicoureteral-reflux with reflux nephropathy without hydroureter, unspecified
- N13.73 Vesicoureteral-reflux with reflux nephropathy with hydroureterNon-billable
- N13.731 Vesicoureteral-reflux with reflux nephropathy with hydroureter, unilateral
- N13.732 Vesicoureteral-reflux with reflux nephropathy with hydroureter, bilateral
- N13.739 Vesicoureteral-reflux with reflux nephropathy with hydroureter, unspecified
- N13.8 Other obstructive and reflux uropathy
- N13.9 Obstructive and reflux uropathy, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the N13 range.
Hydroureter
Dilatation of the ureter caused by obstruction of urine flow.
Pyonephrosis
Distention of KIDNEY with the presence of PUS and suppurative destruction of the renal parenchyma. It is often associated with renal obstruction and can lead to total or nearly total loss of renal function.
Retroperitoneal Fibrosis
A slowly progressive condition of unknown etiology, characterized by deposition of fibrous tissue in the retroperitoneal space compressing the ureters, great vessels, bile duct, and other structures. When associated with abdominal aortic aneurysm, it may be called chronic periaortitis or inflammatory perianeurysmal fibrosis.
Vesico-Ureteral Reflux
Retrograde flow of urine from the URINARY BLADDER into the URETER. This is often due to incompetence of the vesicoureteral valve.
About the N13 Code Range
These conditions involve urinary tract obstruction or reflux, meaning backward flow. The categories distinguish problems involving the kidney, ureter, or both.
The hydronephrosis branches distinguish obstruction at the ureteropelvic junction, ureteral narrowing, kidney and ureter stones, and other or unspecified forms. Other branches identify N13.4 hydroureter, N13.5 a crossing vessel or ureteral narrowing without hydronephrosis, and N13.6 pyonephrosis.
N13.7 divides vesicoureteral reflux by whether reflux nephropathy and hydroureter are present. Its further subdivisions distinguish one-sided, both-sided, and unspecified cases.
Questions About This Page
How many billable codes are in the N13 range?
Of the 23 codes in this range, 18 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the N13 range classify?
The range classifies obstructive and reflux uropathy. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
