This paper, the first in a series of three, sets the stage for two accompanying papers detailing a pair of groundbreaking initiatives to support "at risk" caregivers of high-needs older persons and children in Toronto. Although caregiver burden and stress are often conceptualized primarily as a function of the needs of cared-for persons and the capacity of caregivers, fragmented formal care systems also play a key role. Solutions must take individual-level and system-level factors into account; clarify expectations about what we expect unpaid caregivers to do; redefine the unit of care to include caregivers; and think beyond short-term fixes to mechanisms, such as interdisciplinary teams and integrated care plans, that promote forward planning, accountability, best practices and crisis avoidance.