| N13 | Obstructive and reflux uropathy | NON-BILLABLE CODE |
| N13.0 | Hydronephrosis with ureteropelvic junction obstruction | BILLABLE CODE |
| N13.1 | Hydronephrosis with ureteral stricture, not elsewhere classified | BILLABLE CODE |
| N13.2 | Hydronephrosis with renal and ureteral calculous obstruction | BILLABLE CODE |
| N13.3 | Other and unspecified hydronephrosis | NON-BILLABLE CODE |
| N13.30 | Unspecified hydronephrosis | BILLABLE CODE |
| N13.39 | Other hydronephrosis | BILLABLE CODE |
| N13.4 | Hydroureter | BILLABLE CODE |
| N13.5 | Crossing vessel and stricture of ureter without hydronephrosis | BILLABLE CODE |
| N13.6 | Pyonephrosis | BILLABLE CODE |
| N13.7 | Vesicoureteral-reflux | NON-BILLABLE CODE |
| N13.70 | Vesicoureteral-reflux, unspecified | BILLABLE CODE |
| N13.71 | Vesicoureteral-reflux without reflux nephropathy | BILLABLE CODE |
| N13.72 | Vesicoureteral-reflux with reflux nephropathy without hydroureter | NON-BILLABLE CODE |
| N13.721 | Vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral | BILLABLE CODE |
| N13.722 | Vesicoureteral-reflux with reflux nephropathy without hydroureter, bilateral | BILLABLE CODE |
| N13.729 | Vesicoureteral-reflux with reflux nephropathy without hydroureter, unspecified | BILLABLE CODE |
| N13.73 | Vesicoureteral-reflux with reflux nephropathy with hydroureter | NON-BILLABLE CODE |
| N13.731 | Vesicoureteral-reflux with reflux nephropathy with hydroureter, unilateral | BILLABLE CODE |
| N13.732 | Vesicoureteral-reflux with reflux nephropathy with hydroureter, bilateral | BILLABLE CODE |
| N13.739 | Vesicoureteral-reflux with reflux nephropathy with hydroureter, unspecified | BILLABLE CODE |
| N13.8 | Other obstructive and reflux uropathy | BILLABLE CODE |
