ICD-10 Code A59.03 – Trichomonal cystitis and urethritis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A59.03 – Trichomonal cystitis and urethritis
What it is
A59.03 identifies trichomonal infection involving the bladder and urethra. Use it when documentation specifies trichomoniasis affecting these urinary tract sites.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include dysuria, urinary frequency, urethral irritation, or cystitis-like symptoms when trichomonas is confirmed or clearly documented.
When to use this code
Use this code when the provider documents trichomonal cystitis, trichomonal urethritis, or both together. It is appropriate when the infection is identified as due to Trichomonas vaginalis and the urinary tract site is specified.
If the record only says trichomoniasis without a urinary tract site, check documentation before assigning A59.03. Code the documented condition as written and confirm whether another site or a different trichomoniasis code applies.
Do not use for
Do not use A59.03 for nonspecific urinary tract infection, bacterial cystitis, or urethritis without trichomonal documentation. Check documentation if the organism or anatomic site is not stated.
Coding tip
Confirm both the organism and the urinary tract site in the note before selecting A59.03.