Background People with advanced, serious illnesses experience a high burden of physical and psychosocial symptoms, limitations in functioning, and declining quality of life (QOL) over the course of their illness. Caring for these patients can take a significant physical and emotional toll on their caregivers as well. Palliative care has been defined as ''patient-and family-centered care that optimizes QOL by anticipating, preventing, and treating suffering. Palliative care throughout the continuum of illness involves addressing physical, intellectual, emotional, social, and spiritual needs and facilitating patient autonomy, access to information, and choice.'' 1,2 Evidence reviews show that receipt of palliative care can provide clinically meaningful relief of a broad range of patient symptoms, reduce caregiver burden, and improve patient and caregiver QOL. 3e5 At the same time, patients and caregivers report significant barriers to receiving comprehensive palliative care services (i.e., care that facilitates advance care planning [ACP] and medical decision-making, systematically assesses and manages patient symptoms, and addresses caregiver burden). Access to comprehensive palliative care is typically limited to either inpatient hospitals or endof-life hospice settings. Thus, patients who are not terminally ill and their caregivers report an unmet need for receiving palliative care where they live (i.e., in their communities). 6 The challenge of accessing effective palliative care services is only expected to exacerbate, due to increasing demand from the aging U.S. population with multiple comorbid health conditions and limited supply from a projected shortage of competent clinicians to provide these services. 5 There is an urgent need for research studies to generate evidence for identifying the optimal mix of providers, settings, and content of palliative care needed at different stages of an advanced illness, from diagnosis until death. In the following section, we discuss the Patient-Centered Outcome Research Institute's (PCORI's) current and future investments in research on palliative care.