A59.03 ICD-10-CM Code: Trichomonal cystitis and urethritis
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Infections with a predominantly sexual mode of transmission (A50-A64)
A59.03
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceTrichomonal cystitis and urethritis
This is a urinary tract infection caused by a parasite called Trichomonas, affecting the bladder and urethra (the tube that carries urine). It causes inflammation and irritation in these areas, leading to symptoms like painful urination and frequent urges to urinate.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
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Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for A59.03 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A59.03 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A59.03 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A59.03 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A59.03 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A59.03 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A59.03 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is A59.03 an HCC code?
No. A59.03 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
A59.03 is the ICD-10-CM diagnosis code for trichomonal cystitis and urethritis. This is a urinary tract infection caused by a parasite called Trichomonas, affecting the bladder and urethra (the tube that carries urine). It causes inflammation and irritation in these areas, leading to symptoms like painful urination and frequent urges to urinate. A59.03 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).
A59.03 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
This code is specific to trichomonal infection of both the cystitis (bladder) and urethritis (urethra); do not use if only one site is affected.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A59.03 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code is specific to trichomonal infection of both the cystitis (bladder) and urethritis (urethra); do not use if only one site is affected
- •Verify documentation confirms Trichomonas vaginalis as the causative organism and confirm both bladder and urethral involvement before assigning this code