Background Family caregivers' experiences of formal care when caring for persons with dementia through the process of the disease is sparsely investigated. Aims To investigate family caregivers' experiences of formal care when caring for a person with dementia, through the stages of the disease. Design A qualitative approach with focus group interviews. Methods Four focus group interviews were conducted in October 2011 with 23 spouses and adult children of persons with dementia and analysed with content analysis. Results The participants' experiences of formal care when caring for a person with dementia were captured in the theme ‘Family caregiving requires collaboration with formal care to get support adjusted to needs specific to the stages of dementia’. This can be broken down into the categories ‘The dementia diagnosis – entry into formal care as a novice family caregiver’, ‘Needing expanded collaboration with formal care to continue care at home’ and ‘Being dependent on a nursing home and trying to maintain involvement’. Conclusion Family caregiving requires collaboration with formal care to get support adjusted to the individual's needs, specific to the stages of dementia. Caregivers experience a transition process with three main turning points: the dementia diagnosis; when they realise increased need for formal care to continue caring at home; and when the person with dementia is moved into a nursing home. The interviewed caregivers experience formal care reactive to their needs and this often promoted unhealthy transitions. Formal care needs to be proactive and deliver available care and support early on in the dementia trajectory. Interventions should focus on facilitating a healthy transition for family caregivers through the trajectory of the dementia disease to ensure their well‐being.