Introduction. Volunteerism in later life is often explained by socioeconomic resources, but family relationships may also shape whether and how older adults engage in unpaid helping activities. This study examined whether family-related factors help explain differences in formal and informal volunteerism between Asian midlife and older adults and other ethnoracial groups in the United States. Methods. Data were drawn from pooled 2004-2020 waves of the Health and Retirement Study, using a cross-sectional sample of adults aged 50 to 75. Logistic regression models estimated the odds of formal and informal volunteerism across ethnoracial groups, with Asians as the reference group. Models first adjusted for demographic characteristics (e.g., health, education), and then added family-related factors, including family network composition, household size, contact with family members, financial support, and positive and negative emotional support. Results. More frequent contact with family members was associated with higher odds of both formal (OR = 1.197, p < .01) and informal volunteerism (OR = 1.342, p < .001). In contrast, negative emotional support from family, such as criticism, excessive demands, or feeling let down by relatives, was associated with lower odds of both formal (OR = .294, p < .05) and informal volunteerism (OR = .219, p < .01). Larger household size was also associated with lower odds of informal volunteerism (OR = .686, p < .01). However, even after accounting for these family-related factors, differences between Asians and Whites remained significant for both formal (OR = 1.635, p < .05) and informal volunteerism (OR = 1.782, p < .01). Conclusion. These findings suggest that family relationships are relevant to volunteerism in later life, but do not fully explain ethnoracial differences involving Asians. Policies aimed at promoting volunteer engagement should therefore take family context into account, particularly when designing outreach and support strategies for diverse ethnoracial groups.