Most of the oldest old experience physical and cognitive decline and suffer the loss of independence. This chapter concerns those 85 and beyond who are the “oldest old”. Often called the “Fourth Age” of life, a time of decline and disability, this life phase begins whenever health starts to decline dramatically, and for some this is well before 85. Acceptance of advancing age and its accompanying decline in health is a central developmental theme of the fourth age. Protective factors include adequate access to services and social support, nutritious food, spiritual beliefs, and regular exercise and activities. Risk factors for poor outcomes derive mainly from failing health. The chapter explains the theories of loss and grief that can guide practice with the oldest old and possible interventions useful for work with oldest-old adults experiencing loss.