Coding for STI Screening in Pregnancy

Screening for sexually transmitted infections (STIs) during pregnancy is essential for safeguarding maternal and fetal health. According to the CDC, nearly one in five Americans had an STI on any given day in 2018, with direct medical costs reaching $16 billion. Untreated STIs in pregnancy can lead to serious complications, including preterm birth and neonatal infections. 

Accurate coding ensures appropriate testing, documentation, and reimbursement. This discussion highlights key coding considerations for STI screening in pregnancy, including current CDC guidelines for testing syphilis, gonorrhea, and chlamydia. Proper coding supports effective clinical care and helps prevent the spread of infections during pregnancy.

Encounter Codes (ICD-10-CM) for Ordering Tests

It is essential to begin with the appropriate encounter diagnosis codes from ICD-10-CM to ensure accurate coding when ordering STI screening tests during pregnancy. 

Here is the complete list of ICD-10-CM encounter codes used when ordering STI screening during pregnancy, including pregnancy-related supervision, high-risk behaviors, and lifestyle considerations. Each code is listed with its official description. One code in your sample appears to reference a CPT/HCPCS code (G0472) but lacks context in this ICD-10-CM list; this is addressed at the end.

Screening and Carrier Status

• Z11.3 – Encounter for screening for infections with a predominantly sexual mode of transmission
• Z11.59 – Encounter for screening for other infectious and parasitic diseases
• Z22.8 – Carrier of other infectious disease

Pregnancy Status and Supervision

• Z33.1 – Pregnant state, incidental
• Z34.00 – Encounter for supervision of normal first pregnancy, unspecified trimester
• Z34.01 – Encounter for supervision of normal first pregnancy, first trimester
• Z34.02 – Encounter for supervision of normal first pregnancy, second trimester
• Z34.03 – Encounter for supervision of normal first pregnancy, third trimester
• Z34.80 – Encounter for supervision of other normal pregnancy, unspecified trimester
• Z34.81 – Encounter for supervision of other normal pregnancy, first trimester
• Z34.82 – Encounter for supervision of other normal pregnancy, second trimester
• Z34.83 – Encounter for supervision of other normal pregnancy, third trimester
• Z34.90 – Encounter for supervision of normal pregnancy, unspecified, unspecified trimester
• Z34.91 – Encounter for supervision of normal pregnancy, unspecified, first trimester
• Z34.92 – Encounter for supervision of normal pregnancy, unspecified, second trimester
• Z34.93 – Encounter for supervision of normal pregnancy, unspecified, third trimester

Behavior and Lifestyle Risk Factors

• Z72.51 – High-risk heterosexual behavior
• Z72.52 – High-risk homosexual behavior
• Z72.53 – High-risk bisexual behavior
• Z72.89 – Other lifestyle-related problems (Note: To be used in conjunction with HCPCS code G0472, which refers to hepatitis screening; its exact relevance to STI screening must be clarified before use.)

Medical History

• Z86.19 – Personal history of other infectious and parasitic diseases

High-Risk Pregnancy Supervision

• O09.90 – Supervision of high-risk pregnancy, unspecified, unspecified trimester
• O09.91 – Supervision of high-risk pregnancy, unspecified, first trimester
• O09.92 – Supervision of high-risk pregnancy, unspecified, second trimester
• O09.93 – Supervision of high-risk pregnancy, unspecified, third trimester

Note on Ambiguity

Z72.89, Other lifestyle problems are noted in your list to be “used with HCPCS code G0472.”

• G0472 is a HCPCS code for Hepatitis screening, not an ICD-10-CM code.
• Its use here is ambiguous unless the patient requires hepatitis screening as part of STI risk assessment.
• If not screening for hepatitis, this pairing may not apply.

Procedural Codes (CPT) for Ordering or Billing for STI Screening in Pregnancy

Below is a complete list of CPT/HCPCS procedural codes for billing STI screening in pregnancy.

Chlamydia

• 86631 – Antibody; Chlamydia
• 86632 – Antibody; Chlamydia, IgM
• 87110 – Culture, chlamydia, any source
• 87270 – Infectious agent antigen detection by immunofluorescent technique; Chlamydia trachomatis
• 87320 – Infectious agent antigen detection by immunoassay technique (e.g., EIA, ELISA, FIA, IMCA); qualitative or semiquantitative; Chlamydia trachomatis
• 87490 – Infectious agent detection by nucleic acid (DNA or RNA); Chlamydia trachomatis, direct probe technique
• 87491 – Infectious agent detection by nucleic acid (DNA or RNA); Chlamydia trachomatis, amplified probe technique
• 87800 – Infectious agent detection by nucleic acid (DNA or RNA), multiple organisms; direct probe(s) technique
• Note: Marked with an asterisk in your sample as used for combined chlamydia and gonorrhea testing
• 87810 – Infectious agent antigen detection by immunoassay with direct optical (i.e., visual) observation; Chlamydia trachomatis
• Note: Also marked as used for combined chlamydia and gonorrhea testing

Gonorrhea

• 87590 – Infectious agent detection by nucleic acid (DNA or RNA); Neisseria gonorrhoeae, direct probe technique
• 87591 – Infectious agent detection by nucleic acid (DNA or RNA); Neisseria gonorrhoeae, amplified probe technique
• 87850 – Infectious agent antigen detection by immunoassay with direct optical (i.e., visual) observation; Neisseria gonorrhoeae
• 87800 – See above; repeated for gonorrhea + chlamydia testing

Hepatitis B

• 86704 – Hepatitis B core antibody (HBcAb); total
• 86706 – Hepatitis B surface antibody (HBsAb)
• 87340 – Infectious agent antigen detection by immunoassay (e.g., EIA, ELISA, FIA, IMCA); hepatitis B surface antigen (HBsAg)
• 87341 – Infectious agent antigen detection by immunoassay; hepatitis B surface antigen (HBsAg), neutralization

Hepatitis C

• 86803 – Hepatitis C antibody
• 86804 – Hepatitis C antibody; confirmatory test (e.g., immunoblot)
• 87520 – Infectious agent detection by nucleic acid (DNA or RNA); hepatitis C, direct probe technique
• 87521 – Infectious agent detection by nucleic acid (DNA or RNA); hepatitis C, amplified probe technique (includes reverse transcription)
• 87522 – Infectious agent detection by nucleic acid (DNA or RNA); hepatitis C, quantification (includes reverse transcription)
• 87902 – Infectious agent genotype by nucleic acid (DNA or RNA); hepatitis C virus
• G0472 – Hepatitis C antibody screening at high risk and other covered indication(s) (Medicare-covered code)

HIV

• 86689 – Antibody; HTLV or HIV antibody, confirmatory test (e.g., Western Blot)
• 86701 – Antibody; HIV-1
• 86702 – Antibody; HIV-2
• 87534 – Infectious agent detection by nucleic acid (DNA or RNA); HIV-1, direct probe technique
• 87535 – Infectious agent detection by nucleic acid (DNA or RNA); HIV-1, amplified probe technique (includes reverse transcription)
• 87536 – Infectious agent detection by nucleic acid (DNA or RNA); HIV-1, quantification (includes reverse transcription)
• 87390 – Infectious agent antigen detection by immunoassay (e.g., EIA, ELISA, FIA, IMCA); HIV-1

Syphilis

• 86592 – Syphilis test, non-treponemal antibody; qualitative (e.g., VDRL, RPR, ART)
• 86593 – Syphilis test, non-treponemal antibody; quantitative
• 86780 – Antibody; Treponema pallidum

Evaluation and Management (E/M) Codes for STI Screening in Pregnancy

The following E/M CPT codes are used for office visits related to STI screening, depending on whether the patient is new or established, and on the time spent:

For new patients:

• 99202 is used for visits lasting 15 minutes.
• 99203 is used for visits lasting 30 minutes.
• 99204 is used for visits lasting 45 minutes.
• 99205 is used for visits lasting 60 minutes.

These codes reflect office or other outpatient visits that require a medically appropriate history and/or examination.

For established patients:

• 99211 is used for minimal services that do not require the presence of a physician.
• 99212 is used for visits lasting 10 minutes.
• 99213 is used for visits lasting 20 minutes.
• 99214 is used for visits lasting 30 minutes.
• 99215 is used for visits lasting 40 minutes.

These also reflect medically appropriate outpatient care.

For preventive medicine counseling and risk factor reduction, use:

• 99401 for 15 minutes.
• 99402 for 30 minutes.
• 99403 for 45 minutes.
• 99404 for 60 minutes.

These codes are used when focusing on counseling and risk reduction related to STIs, and should be reported separately from standard E/M services.

Maximize Revenue with BillingFreedom’s Expert OBGYN Medical Billing for STI Screening

Screening for sexually transmitted infections during pregnancy is a key part of women’s health care. With changing guidelines and payer-specific requirements, OB-GYN providers need accurate support for coding and billing.  BillingFreedom specializes in OBGYN medical billing, ensuring that every STI screening from chlamydia to HIV is properly documented using the latest ICD-10, CPT, and E/M codes. We help practices reduce claim denials, stay compliant, and receive timely reimbursements without the added administrative stress.

As demands grow in prenatal care and preventive screening, your focus should remain on patient outcomes, not paperwork. 

BillingFreedom simplifies OBGYN medical billing by managing the entire process from coding to claim follow-up. Whether serving low-risk pregnancies or handling high-risk cases, we ensure your STI screening services are billed accurately so your revenue stays healthy while you focus on patient care.

For more details about our exceptional ob/gyn medical billing services, please don't hesitate to email us at info@billingfreedom.com or call us at +1 (855) 415-3472. 

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