ICD-10 Code A59.9 – Trichomoniasis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A59.9 – Trichomoniasis, unspecified
What it is
A59.9 identifies trichomoniasis when the record confirms infection with Trichomonas but does not specify the site or other details. Use it for an unspecified parasitic genital infection documented by the clinician.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include genital discharge, irritation, dysuria, or discomfort, but you should code only when the diagnosis is documented.
When to use this code
Use A59.9 when the provider documents trichomoniasis and does not identify whether it is vaginal, urethral, or another specified form. It also fits when the note confirms Trichomonas infection but gives insufficient detail for a more specific code.
If the chart later specifies the anatomic site or a different related diagnosis, update the code accordingly. Check documentation when the record only mentions exposure, screening, or a pending test result.
Do not use for
Do not use this code for screening, exposure without infection, or a ruled-out diagnosis. If the documentation specifies a more precise trichomoniasis code, do not default to A59.9.
Coding tip
Query for the organism site when the note says only “trichomoniasis” or “Trichomonas infection.”