This paper examines the relationship between nonmarital cohabitation and routine exchanges of support between American adults aged 19-30 (N = 3,809) and their aging parents, using data drawn from the first wave of the National Survey of Families and Households. Cohabiting young adults were found to be significantly less likely to be exchanging support with their parents than their married or single, noncohabiting counterparts. Cohabiting young adults were also significantly less likely than married young adults to nominate their parents as persons to turn to in an emergency. Analysis of variability in exchanges of support with parents among cohabiting young adults revealed that the quality of the relationship with the parent to be the most potent predictor of exchanges.