The ICD code for UTI (urinary tract infection) is a foundational element in clinical documentation, medical billing, epidemiology, and health system reporting. Accurate ICD-10-CM coding ensures proper reimbursement, supports clinical decision-making, enables quality reporting, and reduces claim denials. UTIs are among the most commonly diagnosed infections across outpatient, emergency, and inpatient settings, making correct code selection clinically and financially critical.
This article provides a comprehensive, coding-accurate, and clinically grounded explanation of the ICD code for UTI, including primary codes, condition-specific variations, documentation requirements, and advanced clinical considerations relevant to coders, billers, clinicians, and compliance professionals.
What Is a Urinary Tract Infection (UTI)?
A urinary tract infection is an infection involving any part of the urinary system, including:
- Urethra
- Bladder
- Ureters
- Kidneys
UTIs may be uncomplicated or complicated, acute or chronic, localized or systemic, and may occur with or without identifiable pathogens. These distinctions directly influence ICD-10-CM code selection.
Primary ICD Code for UTI
ICD-10-CM Code: N39.0
N39.0 – Urinary tract infection, site not specified
This is the most commonly used ICD code for UTI when the medical record confirms a UTI but does not specify the exact anatomical site (e.g., bladder, kidney).
Key Characteristics of N39.0
- Used when documentation states “UTI” without further localization
- Applicable in outpatient, inpatient, and emergency settings
- Considered a billable/specific ICD-10-CM code
- Requires supporting clinical evidence such as symptoms, urinalysis, or culture
When NOT to Use N39.0
N39.0 should not be used when the provider documents a more specific diagnosis. ICD-10-CM guidelines require the highest level of specificity supported by the record.
Site-Specific ICD Codes for UTI
ICD Codes Based on Anatomical Location
Acute Cystitis (Bladder Infection)
- N30.00 – Acute cystitis without hematuria
- N30.01 – Acute cystitis with hematuria
Chronic or Recurrent Cystitis
- N30.10 – Interstitial cystitis (chronic) without hematuria
- N30.11 – Interstitial cystitis with hematuria
Pyelonephritis (Kidney Infection)
- N10 – Acute pyelonephritis
- N11.0 – Nonobstructive reflux-associated chronic pyelonephritis
- N11.1 – Chronic obstructive pyelonephritis
Urethritis
- N34.1 – Nonspecific urethritis
ICD Codes for UTI With Identified Organisms
When laboratory results identify a causative organism, additional codes are required.
Common Organism Codes (Use Secondary Codes)
- B96.20 – Escherichia coli as the cause of diseases classified elsewhere
- B96.1 – Klebsiella pneumoniae
- B95.2 – Enterococcus species
These codes must not be used as primary diagnoses and must follow a site-specific or N39.0 code.
Complicated vs Uncomplicated UTI Coding
Uncomplicated UTI
- Typically coded as N39.0 or N30.00
- Occurs in healthy, nonpregnant individuals
- No structural or functional abnormalities
Complicated UTI
Requires additional codes for underlying conditions such as:
- E11.9 – Type 2 diabetes mellitus
- N13.6 – Pyonephrosis
- Z96.0 – Presence of urogenital implants
ICD Code for UTI in Special Populations
UTI in Pregnancy
- O23.40 – Unspecified infection of urinary tract in pregnancy
Trimester-specific extensions are required.
Pediatric UTI
- Use site-specific codes when documented
- Consider congenital anomalies (Q62–Q64 codes)
Catheter-Associated UTI (CAUTI)
- T83.511A – Infection due to indwelling urinary catheter, initial encounter
- Must be paired with N39.0 or site-specific infection code
Documentation Requirements for Accurate UTI Coding
Accurate ICD coding depends on precise provider documentation. The medical record should include:
- Anatomical site of infection
- Acute vs chronic status
- Presence of hematuria
- Identified organism
- Associated conditions (pregnancy, catheter use, diabetes)
Insufficient documentation defaults coding to N39.0, which may reduce specificity and impact reimbursement.
Common Coding Errors With UTI ICD Codes
- Using N39.0 when cystitis or pyelonephritis is documented
- Missing organism codes when cultures are positive
- Coding symptoms (dysuria, frequency) instead of confirmed UTI
- Assigning CAUTI codes without documentation of catheter causality
Unique Clinical Takeaways
1. Symptom-Based Diagnosis vs Confirmed Infection
Not all urinary symptoms indicate a true UTI. Dysuria, urgency, or frequency without bacteriuria may represent urethral syndrome or interstitial cystitis. Coding a UTI without laboratory or clinical confirmation can result in diagnostic inaccuracy and payer audits. Clinicians should differentiate asymptomatic bacteriuria, which often does not warrant treatment or UTI coding.
2. Recurrent UTI and Coding Implications
Recurrent UTIs require careful longitudinal documentation. Repeated use of N39.0 without identifying patterns, risk factors, or chronicity may obscure underlying causes such as vesicoureteral reflux, nephrolithiasis, or estrogen deficiency. Coding should reflect chronic or recurrent conditions when supported to improve care continuity.
3. Antibiotic Stewardship and ICD Coding
Accurate UTI coding plays a role in antibiotic stewardship programs. Overuse of nonspecific UTI codes contributes to inappropriate antibiotic prescribing metrics. Precise coding aligned with culture results and clinical severity supports institutional quality measures and reduces antimicrobial resistance risk.
ICD-10-CM Guidelines Relevant to UTI Coding
- Code confirmed diagnoses over suspected conditions
- Use additional codes to identify infectious agents
- Do not code ruled-out UTIs
- Sequence underlying conditions when applicable
These guidelines are established by the Centers for Medicare & Medicaid Services (CMS) and the National Center for Health Statistics (NCHS).
UTI ICD Codes and Medical Billing Impact
Correct ICD coding affects:
- Claim acceptance and reimbursement
- Risk adjustment and quality scores
- Audit exposure
- Population health analytics
Payers may deny claims for lack of specificity or mismatched diagnosis-procedure relationships when UTI codes are inaccurately assigned.
Frequently Asked Questions (FAQs)
What is the most common ICD code for UTI?
N39.0 – Urinary tract infection, site not specified
Can N39.0 be used for bladder infections?
Only if cystitis is not specifically documented. If documented, N30.00 or N30.01 should be used.
Is bacteriuria always coded as UTI?
No. Asymptomatic bacteriuria is coded separately and does not equal a UTI diagnosis.
Medical Disclaimer
This content is for informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment. Coding decisions should be based on complete clinical documentation, official ICD-10-CM guidelines, and payer-specific policies. Always consult qualified healthcare and coding professionals for case-specific guidance