The objective of this analysis is to study physical traumatic injury as a risk factor for suicide ideation and attempts. The analysis is retrospective, focusing on inpatient readmission with suicide ideation or intentional self-harm within one year of hospitalization as a trauma alert (TA). Injured patients were divided into TA and emergencies without activation (EMWA) of trauma services. We estimated the probability of readmission with suicide ideation or intentional self-harm using a logistic regression. Rates of readmission with intentional self-harm and suicide ideation were on average 60 and 45% higher for the TA group (p < 0.01). Over 80% of patients readmitted with intentional self-harm or suicide ideation had a preexisting mental health condition, compared to approximately 45% in the overall sample. Logistic regression results indicate these patients had an odds-ratio of near six, predicting the readmission. When patients with a preexisting mental health condition were excluded from the analysis, TA patients were significantly more likely to experience a readmission with intentional self-harm and suicide ideation. Demographic and socioeconomic characteristics (gender, age, race, insurance status, and median incomes) as well as injury type (traumatic brain injury or TBI) also help predict readmission with suicide ideation and intentional self-harm. The main risk factors for reengagement with self-harm and suicidal ideation/attempt include preexisting mental health conditions, TA status, and socioeconomic status. Targeted, sustained, and prolonged rehabilitation and trauma-informed therapy for this high-risk group of severely injured patients may yield significant health and social benefits.