 To date, RDS-CTTN and VBS have enrolled approximately 45 of their samples RDS-CTTN 13383000; VBS 174400. Participants in both samples evidence high rates of risk factors substance use, incarceration, homelessness, unemployment. As hypothesized, PDIRDS is reaching a population with higher rates of risk factors, and lower rates of HIV testing compared to VBS. Almost all in RDS-CTTN and VBS had been tested at least once previously 86, but fewer than half have been tested in the past year. Among those with lifetime testing, data suggest testing is infrequent with a median of 2.5 tests per ten years of adulthood. Interestingly, almost all of those who enroll in RDS-CTTN and VBS elected to test for HIV 90, with no difference in HIV testing acceptance rates between those who tested previously and first-time testers. This suggests that those who enroll in the study, although they have known barriers to HIV testing and a range of risk factors for adverse outcomes, are open to confidential HIV testing. These findings support the promise of the RDS-CTTN approach, but preliminary studies also signal the need to reach those with the greatest fears of and barriers to HIV testing who will not engage in confidential testing. 