2026 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 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N28.85 is a billable ICD-10-CM diagnosis code for pyeloureteritis cystica. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 689 through 690. 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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Infection, infected, infective(opportunistic)
      • kidney (cortex) (hematogenous)
        • pelvis and ureter (cystic)
    • Infection, infected, infective(opportunistic)
      • renal
        • pelvis and ureter (cystic)
    • Pyeloureteritis cystica

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

Clinical InformationClinical

  • Pyelitis

    inflammation of the kidney pelvis and kidney calices where urine is collected before discharge, but does not involve the renal parenchyma (the nephrons) where urine is processed.

  • Ureteritis Glandularis|Ureteritis glandularis

    a benign inflammatory lesion of the ureter characterized by glandular metaplasia of the urethral lining. it is a further proliferative progression of cystitis glandularis.

  • Ureteritis

    an acute or chronic inflammatory process affecting the ureter.

  • Ureteritis Cystica

    a non-neoplastic lesion of the ureter characterized by the presence of multiple submucosal small cysts in the ureteral wall. it is caused by inflammation due to urinary tract stones or infection.

  • Pyelitis

    inflammation of the renal pelvis.

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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N28.85Overview

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, 2025 through September 30, 2026.

What MS-DRG does N28.85 group to?

When pyeloureteritis cystica is the principal diagnosis on an inpatient stay, it groups to MS-DRG 689, 690, with relative weights from 0.8095 to 1.1603 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of N28.85?

Under the General Equivalence Mappings, pyeloureteritis cystica converts to ICD-9-CM 590.3 (pyeloureteritis cystica). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.