Background An academic Ryan White HIV/AIDS Program clinic increased co-located mental health care (MH) services in 2013. The study objectives were to characterize the changing demographics of the people living with HIV (PLWH) who initiated MH and to determine MH initiation’s association with HIV outcomes. Methods The cohort included PLWH who received clinic-based MH services from 2012 to 2014. Cohorts A and B initiated MH before or during 2012 and during 2013–2014, respectively. Demographics were compared for the 2 cohorts, and for Cohort B, pre/post–MH initiation clinical outcomes were compared. Results Compared with Cohort A (n = 130), Cohort B (n = 181) had 3 times the participants with CD4 counts <200 ( P = .02). One-third of Cohort B had detectable viral loads compared with <20% of Cohort A ( P = .01). Cohort B received more substance use diagnoses ( P = .005). Pre/post–MH initiation, engagement in care did not change. For Cohort B, MH initiation was associated with increased rates of viral suppression. For those who were prescribed antiretroviral therapy more than 1 year before MH initiation, participants who were older and nonblack were more likely to achieve viral suppression. Conclusions PLWH who gained access to MH in 2013–2014 were more likely to have lower CD4 counts and detectable viral loads. Engagement in care did not increase with initiation of MH, but initiation of MH was associated with higher rates of viral suppression. Younger and minority patients may not have benefited as much from increased access to co-located MH and substance use services.