Rust, GeorgeMinor, PatrickJordan, NeilMayberry, RobertSatcher, DavidBackground: Patients diagnosed with gonorrhea or chlamydia are at high risk for HIV and syphilis, and should be offered screening for both. Goal: This study measures HIV and syphilis screening rates among Medicaid patients diagnosed with another sexually transmitted disease (STD). Study Design: Using 1998 Medicaid claims data from 4 states, we identified individuals diagnosed with gonorrhea, urogenital chlamydia, or pelvic inflammatory disease, and then measured the proportion receiving screening tests for HIV and syphilis. Results: Only 25% of STD-diagnosed Medicaid patients received screening tests for syphilis and only 15% for HIV. We found significant state-to-state variability in screening rates. Conclusion: Medicaid patients diagnosed with a nonbloodborne STD represent a high-risk group that is not adequately screened for syphilis and HIV despite repeated contact with medical professionals. Interventions should focus on eliminating missed opportunities for screening these high-risk individuals.Public HealthChronic Illness & DiseasesHIV/AidsPracticeResearchgonorrheachlamydiaHIVsyphilisscreeningMedicaid patientssexually transmitted diseaseSTDArticle