Residential care facilities operating without a state license are known to house vulnerable adults. Such unlicensed care homes (UCHs) commonly operate illegally, making them difficult to investigate. We conducted an exploratory, multimethod qualitative study of UCHs, including 17 subject matter expert interviews and site visits to three states, including a total of 30 stakeholder interviews, to understand UCH operations, services provided, and residents served. Findings indicate that various vulnerable groups reside in UCHs; some UCHs offer unsafe living environments; and some residents are reportedly abused, neglected, and financially exploited. Regulations, policies, and practices that might influence UCH prevalence are discussed.