2026 ICD-10-CM Diagnosis Code N99.511Cystostomy infection

ICD-10-CM Codes›N00–N99›N99›N99

ICD-10-CM N99.511
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N99.511 is a billable ICD-10-CM diagnosis code for cystostomy infection. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 698 through 700. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Postprocedural or postoperative genitourinary system complication.

Code Identity

ICD-10-CM Code
N99.511
Billable Status
Yes — Valid for Submission
Code Describes
Cystostomy infection
Short Description
Cystostomy infection
Same as the full description in the CMS dataset.
Parent Code
N99.51
Complication of cystostomy

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN99Intraoperative and postprocedural complications and disorders of genitourinary system, not elsewhere classified
CategoryN99Intraoperative and postprocedural complications and disorders of genitourinary system, not elsewhere classified
This CodeN99.511Cystostomy infection

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.

    • Complication(s) (from) (of)
      • cystostomy (stoma)
        • infection

Clinical ClassificationClinical

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

CCSR GEN026
Postprocedural or postoperative genitourinary system complication
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Ostomy

An ostomy is surgery to create an opening (stoma) from an area inside the body to the outside. It treats certain diseases of the digestive or urinary systems. It can be permanent, when an organ must be removed. It can be temporary, when the organ needs time to heal. The organ could be the small intestine, colon, rectum, or bladder.

Read the full article at MedlinePlus

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

Convert N99.511 to ICD-9-CMHistory

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

ICD-9-CM
596.81 Infection of cystostomy
Exact Match The mapping is direct, with no qualifiers.

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 N99.511Overview

Is N99.511 (Complication of cystostomy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cystostomy infection on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N99.511 group to?

When cystostomy infection is the principal diagnosis on an inpatient stay, it groups to MS-DRG 698, 699, 700, with relative weights from 0.6899 to 1.6544 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of N99.511?

Under the General Equivalence Mappings, cystostomy infection converts to ICD-9-CM 596.81 (infection of cystostomy). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.