2026 ICD-10-CM Diagnosis Code A59.03Trichomonal cystitis and urethritis

ICD-10-CM Codes›A00–B99›A50-A64›A59

ICD-10-CM A59.03
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A59.03 is a billable ICD-10-CM diagnosis code for trichomonal cystitis and urethritis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 727 through 728, 742 through 743, 757 through 759. Coders also document this condition as trichomonal cystitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections; Sexually transmitted infections (excluding HIV and hepatitis); and Urinary tract infections.

Code Identity

ICD-10-CM Code
A59.03
Billable Status
Yes — Valid for Submission
Code Describes
Trichomonal cystitis and urethritis
Short Description
Trichomonal cystitis and urethritis
Same as the full description in the CMS dataset.
Parent Code
A59.0
Urogenital trichomoniasis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA59Trichomoniasis
This CodeA59.03Trichomonal cystitis and urethritis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Trichomonal cystitis
  • Trichomonal urethritis
  • Urogenital infection by Trichomonas vaginalis

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.

    • Cystitis(exudative) (hemorrhagic) (septic) (suppurative)
      • trichomonal
    • Infection, infected, infective(opportunistic)
      • Trichomonas
        • urethra
    • Trichomoniasis
      • bladder
    • Trichomoniasis
      • urethra
    • Urethritis(anterior) (posterior)
      • trichomonal or due to Trichomonas (vaginalis)

Clinical ClassificationClinical

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

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient No · outpatient No
CCSR INF010
Sexually transmitted infections (excluding HIV and hepatitis)
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR GEN004
Urinary tract infections
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Trichomoniasis

Trichomoniasis is a sexually transmitted infection (STI) caused by a parasite. It spreads from person to person during sex. Many people do not have any symptoms. If you do get symptoms, they usually happen within 5 to 28 days after being infected.

Read the full article at MedlinePlus

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

Convert A59.03 to ICD-9-CMHistory

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

ICD-9-CM
131.02 Trichomonal urethritis
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 A59.03Overview

Is A59.03 (Urogenital trichomoniasis) a billable code?

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

What MS-DRG does A59.03 group to?

When trichomonal cystitis and urethritis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 727, 728, 742, 743, 757, 758, 759, with relative weights from 0.6636 to 1.8348 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A59.03?

Under the General Equivalence Mappings, trichomonal cystitis and urethritis converts to ICD-9-CM 131.02 (trichomonal urethritis). The mapping is approximate, so confirm the match fits the documentation.

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.