Despite known benefits, only 19-28% of HIV-infected Americans are virologically suppressed (defined as ≤200 copies/mL). Engagement in HIV care represents a continuum from patients unaware they are infected to virological suppression. The electronic medical record of all newly diagnosed HIV-infected MSM seen at Fenway Health between 2000 and 2010 were reviewed. Patients were "engaged" if they had one negative HIV test and/or one physical exam within 24 months prior to their HIV diagnosis (n=291). All others were considered "new" (n=463). MSM engaged in care prior to HIV diagnosis were more often identified in acute retroviral syndrome or on routine screening, more rapidly linked to care, and less often diagnosed with a concomitant STI than those who were not engaged in care. Nearly 19% of all patients were diagnosed with AIDS the same time they were diagnosed with HIV. Blacks and those with higher CD4 counts at diagnosis were less likely to be virologically suppressed at 1 year. Between 2000 and 2010, patients retained in care were more likely to initiate ART and be virologically suppressed within 1 year independent of initial HIV viral load and CD4 count. Engagement in care prior to seroconversion influences important HIV outcomes. Programs that care for at risk populations should institute routine opt-out HIV testing and test-and-treat programs to optimize HIV care and prevention.