Grandparents throughout the world are increasingly providing childcare for their grandchildren. Research has shown mixed results regarding the mental and physiological health effects of grandchildcare: health benefits or detriments are relative, dependent upon grandparents’ age, health status, race, and socioeconomic status. Gender differences in health and grandchildcare remain understudied and have relied predominantly on non-representative or cross-sectional data. Further, research has shown that vibrant and expansive social and kin networks improve these same health outcomes in older adults, and yet little research has investigated the combination of these networks and transfers. I expand this literature by using the Health and Retirement Study (HRS 2002-2012) to examine the longitudinal effects of grandchildcare on mental and physiological health conditions by gender in the United States. To test role strain or role enhancement theory, I introduce social contact and relationships, such as social engagements with friends and other intergenerational contact, as moderators for grandchildcare. Preliminary findings show that grandfathers experience role strain, or worsening health outcomes and experiences, when coresiding with kin; and role enhancement, or health improvements, when living near kin. This is not the case for grandmothers, who experience role strain more often than role enhancement. This paper expands upon the longitudinal work addressing gendered differences in health in later life, and begins to disentangle the relationships between grandchildcare, intergenerational and social networks, and health in older adults.