Inpatient falls among older adults are a relentless problem, and extant inpatient fall prevention research and interventions lack the older adults' perspectives and experiences of their own fall risk in the hospital. Theory-guided research is essential in nursing, and the purpose of this paper was to describe the process of developing a theoretical framework for a phenomenological nursing study exploring older adults' lived experiences of being at risk for falling in the hospital. Based on philosophical nursing underpinnings, the Health Belief Model (HBM) was selected as the theoretical model. The limitations of the model led to expansion of the model with established concepts associated with accidental falls among older adults. The HBM was selected as the guiding model due to its ability to capture a broad range of perceptions of a health threat. The HBM was expanded with the concepts of embarrassment, independence, fear of falling, dignity and positivity effect. The addition of these concepts made the theoretical framework more applicable to age-related developmental behaviours of older adult and more applicable to nursing research. The Expanded HBM theoretical framework may guide future nursing research to develop fall prevention interventions to decrease fall rates among hospitalized older adults. No Patient or Public Contribution.