Objective: This study assessed how patients who screened positive for housing instability in a clinical outpatient setting perceived stable housing and threats to housing stability—understanding that will help to ensure that their housing needs are addressed. Method: We conducted qualitative interviews with 60 patients (40 men, 20 women) who sought services at a Veterans Affairs Medical Center in a large northeastern city and screened positive on the Veterans Health Administration Homelessness Screening Clinical Reminder. We used a modified grounded-theory approach and constant comparative method to analyze data. Results: Participants identified four core concepts of stable housing: affordable, permanent, comfortable and safe, and structurally and functionally adequate; they also identified three primary threats to housing stability: uncertain finances, the volatile nature of available housing, and personal stressors. Results reflect both physical housing elements and psychological features of home. Conclusions: Health care systems should consider appropriate screening items for their particular service population, ensuring that patients’ needs are addressed along a continuum of housing instability. In addition, it is important to integrate each domain identified by patients into services to mitigate homelessness; existing interventions may have limited capacity to fulfill the domain of comfort and safety.