Prioritizing patient values—who/what matters most—is central to palliative care and critical to treatment decision making. Yet which factors are most important to family caregivers in these decisions remains understudied. Using data from a U.S. national survey of cancer caregivers (N = 1661), we examined differences in factors considered very important by caregivers when partnering with patients in cancer treatment decision making by cancer stage and caregiver sociodemographics. Fifteen factors were rated on a 4-point Likert-scale from ‘very unimportant’ to ‘very important.’ Descriptive statistics were used to characterize caregiver factors and tabulate proportions of importance for each. Generalized linear mixed effect modeling was used to examine the importance of factors by cancer stage, and chi-square analyses were performed to determine associations between caregiver sociodemographics and the five most commonly endorsed factors: quality of life (69%), physical well-being (68%), le