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ICD-10-CM 2027 diagnosis code

N13.4Hydroureter

✓ Billable / specificCC — complication/comorbidity

N13.4 is a valid, billable ICD-10-CM code for hydroureter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Hydroureter.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About N13.4

N13.4 is the ICD-10-CM diagnosis code for hydroureter. It belongs to category N13 (obstructive and reflux uropathy), block N10-N16 (renal tubulo-interstitial diseases) and chapter 14 (diseases of the genitourinary system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within N13 (obstructive and reflux uropathy), N13.4 is specifically for hydroureter. Related codes cover hydronephrosis with ureteropelvic junction obstruction (N13.0), hydronephrosis with ureteral stricture, not elsewhere classified (N13.1), hydronephrosis with renal and ureteral calculous obstruction (N13.2), other and unspecified hydronephrosis (N13.3), Crossing vessel and stricture of ureter without hydronephrosis (N13.5), Pyonephrosis (N13.6), Vesicoureteral-reflux (N13.7), other obstructive and reflux uropathy (N13.8) and 1 more.

Don't report N13.4 together with the conditions in its Excludes1 note: congenital hydroureter (Q62.3-), hydroureter with infection (N13.6) and vesicoureteral-reflux with hydroureter (N13.73-).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 693 (Urinary Stones with MCC, relative weight 1.3168), DRG 694 (Urinary Stones without MCC, relative weight 0.7815), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 593.5 (hydroureter).

Coding notes

Excludes1Not coded here — never report together with this code
  • congenital hydroureter (Q62.3-)
  • hydroureter with infection (N13.6)
  • vesicoureteral-reflux with hydroureter (N13.73-)

Notes that apply from higher levels

Instructions written at a parent level also apply to N13.4.

› From N13 Obstructive and reflux uropathy
Excludes2
  • 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)

Broader instructions also apply from N10-N16 Renal tubulo-interstitial diseases and Chapter 14: Diseases of the genitourinary system.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to N13.4.

Codes whose notes reference N13.4

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 11 · Diseases and Disorders of the Kidney and Urinary Tract

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

ICD-9-CM equivalent

Converter →

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about N13.4

Is N13.4 billable?

Yes. N13.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can N13.4 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict N13.4 as a principal diagnosis.

Is N13.4 a CC or MCC?

N13.4 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does N13.4 group to?

N13.4 is used in the MS-DRG v44.0 logic for MS-DRG 693 (Urinary Stones with MCC), MS-DRG 694 (Urinary Stones without MCC), MS-DRG 791 (Prematurity with Major Problems) and MS-DRG 793 (Full Term Neonate with Major Problems). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for N13.4?

The CMS General Equivalence Mappings map N13.4 to ICD-9-CM 593.5.