ICD-10 Code for UTI (Urinary Tract Infection)

A patient comes in with burning on urination and you already know it’s a UTI before the culture comes back — but the code you pick still depends on what, exactly, you’re treating. N39.0 covers a urinary tract infection when the site isn’t specified, and it’s the single most-used code for this diagnosis in outpatient practices. But it’s not always the right one.

If the infection is confirmed to be in the bladder, or you already know it’s reached the kidney, a more specific code exists — and using it instead of N39.0 usually means fewer payer queries and cleaner claims. This page breaks down when to use N39.0 versus its more specific alternatives, the CPT codes typically billed alongside it, and the documentation details that keep UTI claims from bouncing back.

FY 2027 ICD-10-CM (CMS, eff. 10/1/2026) · CPT 2026 (AMA) · Last verified: October 2026

ICD-10 Code for UTI (Urinary Tract Infection): Full Code List and Related Diagnoses

CPT Codes Commonly Billed With This Diagnosis

*Approximate 2026 CMS national non-facility rate. Lab test rates are from the 2026 CMS Clinical Laboratory Fee Schedule. Rates vary by geography, setting, and payer contract. Refer to the CMS Physician Fee Schedule for official rates.

Which Medical Specialty Handles This?

Most UTIs are treated and coded in primary care or urgent care — a straightforward case rarely needs a specialist. It gets more specific when the infection does not behave like a straightforward case: recurrent UTIs (three or more a year) are typically referred to urology for further workup, a UTI during pregnancy is coded and managed differently in OB/GYN, and a UTI that has climbed to the kidney (pyelonephritis) often needs more aggressive management than a same-day urgent care visit can provide. See our full Family Medicine coding guide for the broader primary-care code set this diagnosis usually sits alongside.

Common Billing & Documentation Mistakes

Coding Tips

• Code to the highest specificity your documentation supports — N30.00/N30.01 (confirmed cystitis) or N10 (pyelonephritis) are stronger claims than N39.0 when the site is actually known.
• In pregnant patients, use the O23.4- series instead of N39.0 — Medicare and most commercial payers require pregnancy-specific coding regardless of trimester.
• Pair the E&M code with 81001 or 81003 (urinalysis) and 87086 (culture) only when both were actually performed and documented — bundling edits will flag a culture billed without a corresponding lab order.
• If the patient has had 3+ UTIs in the past year, document it explicitly as 'recurrent UTI' — this supports both the medical necessity of further workup and a urology referral if needed.

Frequently Asked Questions