What are the ICD‑10 codes for sexually transmitted diseases (STDs)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 20, 2026 • View editorial policy

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question

ICD-10 Codes for Sexually Transmitted Diseases

The ICD-10 coding system includes specific codes for each major sexually transmitted infection, organized primarily in the A50-A64 range for bacterial STDs and B00-B20 range for viral STDs, though validation studies show these codes have high positive predictive values (85-88%) but low sensitivity (9-11%) for case identification.

Primary Bacterial STD Codes

Syphilis (A50-A53)

  • A53.9: Syphilis, unspecified - the most commonly used code in clinical practice 1
  • A50-A52: Specific stages and manifestations of syphilis
  • Latent syphilis had the lowest prevalence among STDs in population studies (5.29/100,000 in 2010) 2

Gonorrhea (A54)

  • A54.9: Gonococcal infection, unspecified - accounts for 1.5% of doxycycline prescriptions in at-risk populations 3
  • The ICD-10 code for gonorrhea has a positive predictive value of 85.0% and specificity of 99.9%, but sensitivity of only 9.7% 1
  • Disease-specific diagnosis codes accurately identify persons with gonorrhea when present, though most cases lack diagnostic coding 1

Chlamydia (A74)

  • A74.9: Chlamydial infection, unspecified - represents 2.6% of encounters with doxycycline prescriptions 3
  • Chlamydia ICD-10 codes demonstrate 87.6% positive predictive value and 99.9% specificity, but only 10.6% sensitivity 1
  • The diagnosis code date occurs on or after laboratory result date in 84.8% of chlamydia cases 1

Viral STD Codes

Human Papillomavirus (HPV) and Genital Warts (A63.0, B97.7)

  • A63.0: Anogenital (venereal) warts
  • Anogenital warts showed the highest rate of increase among viral STDs over the past decade, with rapid increases particularly in men 2
  • Genital warts can be transmitted even after treatment due to persistent subclinical HPV infection 4

Genital Herpes (A60)

  • A60: Anogenital herpes simplex infections
  • By 2021, genital herpes had the highest prevalence of any STD (254.54 per 100,000 persons) 2
  • Viral STDs have shown continuous increases while bacterial STDs declined 2

HIV (B20-B24)

  • B20: Human immunodeficiency virus [HIV] disease
  • HIV exposure and risk codes include Z20.6 (exposure to HIV) and Z29.81 (encounter for HIV preexposure prophylaxis) 3

Risk Behavior and Exposure Codes (Z-codes)

High-Risk Sexual Behavior

  • Z72.52: High-risk homosexual behavior - accounted for 9.9% of encounters indicating increased HIV/STI risk 3
  • Z72.53: High-risk bisexual behavior - represented 1.2% of high-risk encounters 3
  • Z20.2: Contact with and exposure to infections with a predominantly sexual mode of transmission - the most commonly used code at 78.2% of high-risk encounters 3
  • Z20.6: Contact with and exposure to HIV - used in 10.4% of high-risk encounters 3

Other STD Codes

Trichomoniasis

  • Trichomoniasis had the highest prevalence in 2010 (256.65/100,000) but showed a decreasing trend subsequently 2

Unspecified STI

  • A64: Unspecified sexually transmitted disease
  • The unspecified STI code has a low positive predictive value of only 32.0% and negative predictive value >92% 1
  • Only 23.5% of unspecified STI diagnoses occur on or after the laboratory result date 1

Critical Coding Limitations and Pitfalls

Low Sensitivity for Case Identification

  • Disease-specific ICD-10-CM codes accurately identify persons when coded, but low sensitivities (9-11%) mean most individuals cannot be identified in administrative data without laboratory results 1
  • Only 44.6% of available ICD-10-CM codes are actually utilized in ambulatory care, compared to 91.5% of ICD-9-CM codes 5

High Use of Unspecified Codes

  • There was a 108.5% increase in using unspecified codes with ICD-10-CM compared to ICD-9-CM, with 33.3% of ICD-10-CM codes being unspecified versus 14.5% for ICD-9-CM 5
  • This undermines the intended benefit of increased specificity in ICD-10-CM 5

Monitoring Emerging Interventions

  • A new ICD-10 code is needed for monitoring doxycycline post-exposure prophylaxis (doxy PEP) prescriptions, as existing codes cannot adequately track this CDC-recommended intervention 3
  • Before CDC recommendations for doxy PEP, most encounters for potentially eligible patients were not explicitly coded among men who have sex with men 3

Syndrome-Based Coding

  • Among encounters with doxycycline prescriptions, the top ICD-10 codes were symptoms of genitourinary system (R30-R39, 28.7%) and diseases of urinary system (N30-N39, 9.9%), rather than specific STD diagnoses 3
  • Non-STI conditions like asthma (J45, 5.9%) also appear frequently with doxycycline prescriptions 3

References

4
Guideline

Post‑Treatment Transmission and Management of Genital HPV

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

Related Questions

Which ICD‑10‑CM codes should be used to document preventive services for a male partner, including STI screening, HIV testing, hepatitis B vaccination, infectious disease screening, and lifestyle counseling?
What ICD‑10 code should be assigned to a patient recently treated for chlamydia who is now asymptomatic and undergoing a test of cure?
What ICD‑10‑CM diagnostic codes, other than screening codes, can be used for a Pap smear performed as part of the pre‑egg donation work‑up in a 19‑year‑old woman?
What ICD‑10 code should be used for a routine sexually transmitted disease (STD) screening versus screening after known or suspected exposure?
What is the appropriate ICD‑10 code for screening for sexually transmitted infections (STIs)?
A patient inadvertently took vitamin D3 (cholecalciferol) 50,000 IU daily for six days instead of the prescribed once‑weekly regimen; when can the weekly dosing be safely resumed?
What are the symptoms of pharyngeal gonorrhea and how is it diagnosed?
Is pregnancy possible after endometrial ablation, and what are the associated risks?
What does pathologic T3 N0 colon cancer indicate, and is additional staging workup needed to evaluate for metastases?
Is a daily dose of 15 mg diazepam (5 mg three times daily) considered a high dose for a 66‑year‑old woman?
What is the minimum interval before administering the next DTaP (diphtheria, tetanus, acellular pertussis) vaccine after the previous dose?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.