2027 ICD-10-CM Diagnosis Code N28.85Pyeloureteritis cystica

ICD-10-CM Codes›N00–N99›N25-N29›N28

ICD-10-CM N28.85
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N28.85 is a billable ICD-10-CM diagnosis code for pyeloureteritis cystica. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 689 through 690, 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. Coders also document this condition as pyelitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified diseases of kidney and ureters.

Code Identity

ICD-10-CM Code
N28.85
Billable Status
Yes — Valid for Submission
Code Describes
Pyeloureteritis cystica
Short Description
Pyeloureteritis cystica
Same as the full description in the CMS dataset.
Parent Code
N28.8
Other specified disorders of kidney and ureter

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN25-N29Other disorders of kidney and ureter
CategoryN28Other disorders of kidney and ureter, not elsewhere classified
This CodeN28.85Pyeloureteritis cystica

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pyelitis
  • Pyeloureteritis cystica
  • Ureteritis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N28.85: its own notes plus those printed at N28.8, block N25-N29, and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Excludes1

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

From N28.8 Other specified disorders of kidney and ureter applies to 7 codes
  • hydroureter (N13.4)
  • ureteric stricture with hydronephrosis (N13.1)
  • ureteric stricture without hydronephrosis (N13.5)

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 Block N25-N29 Other disorders of kidney and ureter applies to 22 codes
  • disorders of kidney and ureter with urolithiasis (N20-N23)
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 N28.85, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming N28.85: they are not reported together with it, unless the two conditions are unrelated.

  • Block N10-N16 Renal tubulo-interstitial diseases
    pyeloureteritis cystica (N28.85)

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 GEN006
Other specified and unspecified diseases of kidney and ureters
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Urinary Tract Infections

The urinary system is the body's drainage system for removing wastes and extra water. It includes two kidneys, two ureters, a bladder, and a urethra. Urinary tract infections (UTIs) are the second most common type of infection in the body.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert N28.85 to ICD-9-CMHistory

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

ICD-9-CM
590.3 Pyeloureteritis cystica
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N28.85Overview

What is the ICD-10 code for pyeloureteritis cystica?

The ICD-10-CM code for pyeloureteritis cystica is N28.85 (sometimes written as N2885). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N28.85 (Other specified disorders of kidney and ureter) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pyeloureteritis cystica on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N28.85 group to?

When pyeloureteritis cystica is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 689, 690, with relative weights from 0.8008 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is N28.85 a CC or MCC?

CMS lists N28.85 as a CC (complication or comorbidity) for FY 2027. 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.

Can N28.85 be reported with N13.4?

Not as a rule. The Excludes1 note at N28.8, which applies to N28.85, lists "hydroureter (N13.4)". 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).