The present study aimed to identify the structure of advance care planning (ACP) practices implemented by home health nurses (HHNs) for multigenerational families with dependent children and terminally ill grandparents. Interviews of 20 HHNs were conducted. The grounded theory approach was used to describe the interactions among families with dependent children, terminally ill grandparents, and HHNs. The results showed that the structure of ACP practices for multigenerational families with dependent children and terminally ill grandparents was composed of 2 levels. First, HHNs were providing the underlying foundational “Practice of supporting end-of-life care (EOL care) at home” for family members from 2 generations: sandwich generation caregivers (SGCs) and terminally ill grandparents. Second, they were providing “Practices that connect multiple generations,” “Practices that address the children,” and “Practices that involve hands-on experience and communication” for multigenerational families with dependent children and terminally ill grandparents. Practices based on providing stability among family members from 2 generations, SGCs and terminally ill grandparents, were the nursing practice structure that activated ACP for multigenerational families with dependent children and terminally ill grandparents.