Background: In the United States, approximately 568,000 individuals are homeless on a single night. Homelessness can be categorized into three subgroups: sheltered homeless, unsheltered homeless, and unstably housed. Few studies have examined the relations between homelessness subtypes, shelter service utilization, levels of stress experienced, and health risk factors. This study aimed to empirically examine whether shelter status the previous night was related to current stress, recent utilization of shelter-based mental health services, and current health risk factors. Methods: Data were collected at multiple homeless shelters in 2016 in the Oklahoma City area (N=575). All participants completed assessments of demographic characteristics, including age, sex, race, marital status, years of education, and incarceration history and victimization. Multiple linear and logistic regression analyses were conducted to examine relations between homelessness subgroups and outcomes (shelter-based service utilization, health risk factors, and stressors).Results: Results indicated that the sheltered group was younger and more likely to be White than the unsheltered group, had higher levels of education, and reported more lifetime months in jail than the unstably housed group. In addition, unsheltered homeless and unstably housed adults used fewer shelter-based health services, exhibited more health risk factors, experienced greater levels of stress, and had higher levels of food insecurity than sheltered homeless adults.Conclusion: Homeless adults who reside at shelters bene t most from available shelter services. The development of policies and programs targeted toward increasing sheltering options for unsheltered and unstably housed adults is needed.