2026 ICD-10-CM Diagnosis Code N13.0Hydronephrosis with ureteropelvic junction obstruction
ICD-10-CM Codes›N00–N99›N10-N16›N13
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
N13.0 is a billable ICD-10-CM diagnosis code for hydronephrosis with ureteropelvic junction obstruction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 693 through 694, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 226 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified diseases of kidney and ureters.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acquired hydronephrosis
- Acquired hydronephrosis due to ureteral obstruction
- Acquired hydronephrosis due to ureteropelvic junction obstruction
- Acquired obstruction of urinary tract
- Acquired obstructive defect of renal pelvis
- Congenital anomaly of ureter and renal pelvis
- Congenital hydronephrosis
- Congenital hydronephrosis due to ureteral obstruction
- Congenital hydronephrosis due to ureteropelvic junction obstruction
- Congenital obstruction of ureter
- Congenital obstruction of ureteropelvic junction
- Congenital obstructive defect of renal pelvis
- Congenital secondary hydronephrosis
- Obstruction of pelviureteric junction
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Hydronephrosis due to acquired occlusion of ureteropelvic junction
Type 2 Excludes
- Hydronephrosis with ureteropelvic junction obstruction due to calculus N13.2
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
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.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Stricture See Also: Stenosis;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Congenital Hydronephrosis
collection of urine in the renal pelvis that results in dilatation of the renal pelvis and calyces that is present at birth.
Patient EducationClinical
Kidney Diseases
You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert N13.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement N13.0 replaces the following previously assigned code(s):
- N13.1 - Hydronephrosis w ureteral stricture, NEC
Questions About N13.0Overview
What is the ICD-10 code for hydronephrosis with ureteropelvic junction obstruction?
The ICD-10-CM code for hydronephrosis with ureteropelvic junction obstruction is N13.0 (sometimes written as N130). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is N13.0 (Obstructive and reflux uropathy) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report hydronephrosis with ureteropelvic junction obstruction on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does N13.0 group to?
When hydronephrosis with ureteropelvic junction obstruction is the principal diagnosis on an inpatient stay, it groups to MS-DRG 693, 694, 791, 793, with relative weights from 0.7817 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is N13.0 a CC or MCC?
CMS lists N13.0 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 226 closely related codes in its exclusion list.
What is the ICD-9 equivalent of N13.0?
Under the General Equivalence Mappings, hydronephrosis with ureteropelvic junction obstruction converts to ICD-9-CM 591 (hydronephrosis) and 593.3 (stricture of ureter). The mapping is approximate, so confirm the match fits the documentation.
