Frailty, multimorbidity, and care complexity frequently intersect in the lives of older adults living in the community, creating layered challenges for practitioners and health systems. Frailty is commonly understood as reduced physiological reserve and increased vulnerability to stressors, such that minor illness or environmental change can result in significant functional decline. Multimorbidity—the presence of two or more chronic conditions—further compounds risk through increased clinical demands, medication burden, and the need for coordination across multiple services. Although both are core elements of clinical assessment, they represent only part of the broader factors shaping older people’s experiences and outcomes. Care complexity extends beyond clinical diagnoses to include psychological well-being, cognition, social networks, environmental stability, and the adequacy of supports. Factors such as loneliness, caregiver strain, financial insecurity, and housing quality may influence health trajectories. As a result, traditional disease-focused models often fall short in community settings, where the dynamic interaction of these holistic elements shapes outcomes. The ImPaCt Study explored how nurses and allied health professionals understand and respond to complexity in community settings. Focus groups highlighted the importance of shared terminology, noting that inconsistent interpretations of “complexity” can hinder communication, referral, and care planning. Clinicians described complexity as dynamic rather than fixed, shaped by a person’s health status, context, and goals over time. A practice-informed definition of complexity that encompasses the interaction of holistic life factors, which, when considered alongside a person’s goals, alter expected outcomes. Integrating frailty, multimorbidity, and complexity supports more person-centred, anticipatory care and improved outcomes for older people living at home.