The Interpersonal–Psychological Theory of Suicide (IPTS) proposes that combinations of thwarted belongingness, perceived burdensomeness, and acquired capability lead to suicide ideation, planning, and attempting. We compared individuals with and without suicidality on thwarted belongingness and perceived burdensomeness, and compared a combined group of planners and attempters to ideators on fearlessness about death (one component of acquired capability). Individuals with suicidality had higher thwarted belongingness and perceived burdensomeness than individuals without suicidality. Planners and attempters did not have higher fearlessness about death than ideators. These findings partially support IPTS hypotheses. Assessing thwarted belongingness and perceived burdensomeness may improve suicide risk determination.