2027 ICD-10-CM Diagnosis Code N13.721Vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral

ICD-10-CM Codes›N00–N99›N10-N16›N13

ICD-10-CM N13.721
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N13.721 is a billable ICD-10-CM diagnosis code for vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 698 through 700. Coders also document this condition as reflux nephropathy of left kidney due to vesicoureteral reflux. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Vesicoureteral reflux.

Code Identity

ICD-10-CM Code
N13.721
Billable Status
Yes — Valid for Submission
Code Describes
Vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral
Short Description
Vesicoureter-reflux w reflux nephrop w/o hydrourt, unil
Parent Code
N13.72
Vesicoureteral-reflux with reflux nephropathy without hydroureter

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN10-N16Renal tubulo-interstitial diseases
CategoryN13Obstructive and reflux uropathy
This CodeN13.721Vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Reflux nephropathy of left kidney due to vesicoureteral reflux
  • Reflux nephropathy of right kidney due to vesicoureteral reflux
  • Secondary left vesicoureteral reflux grade 2
  • Secondary right vesicoureteral reflux grade 2

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N13.721: its own notes plus those printed at N13.7, N13, block N10-N16, and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block N10-N16 Renal tubulo-interstitial diseases applies to 35 codes
  • pyelonephritis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From N13.7 Vesicoureteral-reflux applies to 8 codes
  • reflux-associated pyelonephritis (N11.0)
From Block N10-N16 Renal tubulo-interstitial diseases applies to 35 codes
  • pyeloureteritis cystica (N28.85)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From N13 Obstructive and reflux uropathy applies to 18 codes
  • 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)
From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name N13.721, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming N13.721: they are not reported together with it, unless the two conditions are unrelated.

  • N11.1 Chronic obstructive pyelonephritis
    obstructive uropathy (N13.-) names N13.-, which includes this code

Code Also 3

These codes say N13.721 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • N80.A4 Superficial endometriosis of ureter
    if applicable, obstructive and reflux uropathy (N13.-) names N13.-, which includes this code
  • N80.A5 Deep endometriosis of ureter
    if applicable, obstructive and reflux uropathy (N13.-) names N13.-, which includes this code
  • N80.A6 Endometriosis of ureter, unspecified depth
    if applicable, obstructive and reflux uropathy (N13.-) names N13.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR GEN011
Vesicoureteral reflux
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Vesico-Ureteral Reflux

    retrograde flow of urine from the urinary bladder into the ureter. this is often due to incompetence of the vesicoureteral valve.

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 N13.721 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
593.71 Vscurt rflx npht uniltrl
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2023No changes
FY 2024RevisedCode revised
FY 2025–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N13.721Overview

Is N13.721 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N13.721 group to?

When vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral is the principal diagnosis on an inpatient stay, it groups to MS-DRG 699, 698, 700, with relative weights from 0.6740 to 1.6400 depending on complications. Higher weights mean higher Medicare reimbursement.

Can N13.721 be reported with N11.0?

Not as a rule. The Excludes1 note at N13.7, which applies to N13.721, lists "reflux-associated pyelonephritis (N11.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of N13.721?

Under the General Equivalence Mappings, vesicoureteral-reflux with reflux nephropathy without hydroureter, unilateral converts to ICD-9-CM 593.71 (vscurt rflx npht uniltrl). The mapping is approximate, so confirm the match fits the documentation.