What ICD‑10 code should be used for a routine sexually transmitted disease (STD) screening versus screening after known or suspected exposure?

ICD-10 Coding for STD Screening

For routine STD screening in asymptomatic patients, use ICD-10 code Z11.3 (Encounter for screening for infections with a predominantly sexual mode of transmission). 1

Primary Screening Code

• Z11.3 is the appropriate code for all routine STD screening encounters when patients have no symptoms and are being tested as part of preventive care, regardless of their risk level. 1
• This code applies to screening for chlamydia, gonorrhea, syphilis, HIV, and other sexually transmitted infections in asymptomatic individuals. 2, 1

When to Use Z11.3

High-Risk Populations Requiring Routine Screening

• All sexually active females aged <25 years should be screened at least annually for chlamydia and gonorrhea using Z11.3. 2, 1
• Young sexually active men in settings where prevalence is ≥2% should receive routine screening coded as Z11.3. 2, 1
• Persons entering correctional and detention facilities should be screened for syphilis, gonorrhea, and chlamydia using Z11.3, ideally within the first 24 hours. 2, 1
• Adolescents in institutional settings (schools, Job Corps, community programs) should be screened when prevalence is ≥2%, coded as Z11.3. 2, 1
• HIV-infected persons who are sexually active should be screened regularly for STDs using Z11.3. 2

Annual Screening Protocols

• Women aged >25 years with risk factors (new partner, multiple partners, partner with concurrent partners) should be screened annually using Z11.3. 2
• Men who have sex with men (MSM) should be screened at anatomic sites of exposure annually using Z11.3. 2
• Persons with previous STD history should be screened at least annually using Z11.3. 2

Alternative Codes for Specific Scenarios

Known or Suspected Exposure (NOT Routine Screening)

• Z20.2 (Contact with and exposure to infections with a predominantly sexual mode of transmission) should be used when a patient presents after known sexual contact with someone diagnosed with an STI. 3
• Z20.6 (Contact with and exposure to HIV) is appropriate for encounters specifically related to HIV exposure. 3
• Z72.52 (High-risk homosexual behavior) and Z72.53 (High-risk bisexual behavior) can document sexual risk behaviors but are used less frequently than Z20.2. 3

When Symptoms Are Present

• Do NOT use Z11.3 if the patient has symptoms such as urethral discharge, dysuria, genital lesions, or pelvic pain. 2
• Use symptom-specific codes (R30-R39 for genitourinary symptoms) or disease-specific codes (A54.9 for gonorrhea, A74.9 for chlamydia, A53.9 for syphilis) when testing symptomatic patients. 3, 4

Critical Coding Pitfalls to Avoid

Common Misconceptions

• Pap tests are NOT STD screening tests and should never be coded as Z11.3. 2, 1
• Cervical cancer screening (Pap tests) should be coded separately using appropriate cervical screening codes, not STD screening codes. 2, 1
• HPV DNA testing is not considered STD screening and should not be coded as Z11.3 when performed as part of cervical cancer screening protocols. 2, 5

Documentation Requirements

• The presence of mucopurulent discharge or vaginal infections should not delay STD testing, but if symptoms are present, do not use Z11.3. 2
• Z11.3 is specifically for asymptomatic screening encounters only. 1
• When doxycycline is prescribed for STD treatment (not doxy PEP), use disease-specific codes rather than screening codes. 3

Practical Application Algorithm

1. Is the patient asymptomatic?

   • Yes → Proceed to step 2
   • No → Use symptom-specific or disease-specific codes, NOT Z11.3

2. Is this routine screening or known exposure?

   • Routine screening → Use Z11.3 1
   • Known exposure to partner with STI → Use Z20.2 3
   • Known HIV exposure → Use Z20.6 3

3. Is this a Pap test or HPV test for cervical cancer screening?

   • Yes → Do NOT use Z11.3; use cervical screening codes 1
   • No → Z11.3 is appropriate for STD screening 1

Monitoring and Follow-Up Coding

• Retesting at 3 months after positive chlamydia or gonorrhea should still use Z11.3 if the patient is asymptomatic, as this represents screening for reinfection. 2
• Annual screening in high-risk populations should consistently use Z11.3 for each screening encounter. 2, 1