Although researchers have focused on adult children's intergenerational solidarity with their parents following the transition to adulthood, less is known about continuity and change in the multiple dimensions of solidarity as children transition from emerging to established adulthood. Therefore, we focused on reciprocal longitudinal associations between dimensions of latent forms of solidarity (normative and affectual solidarity) and manifest forms of solidarity (associational and functional solidarity) as reported by young adults at three stages from emerging to established adulthood. Data were derived from young adult children participating in the Longitudinal Study of Generations who reported about 260 daughter-mother, 214 son-mother, 244 daughter-father, and 205 son-father relationships in 2000 (18-29 years old), 2005 (23-34 years old), and 2016 (34-45 years old). Multigroup autoregressive cross-lagged models prospectively predicted reciprocal influences among the dimensions of solidarity across four parent-child gender groups. Results showed that young adults' perceived intergenerational solidarity with parents was stable across three-time points. In addition, young adults' perceived associational solidarity with parents in emerging adulthood (2000 survey) predicted functional solidarity with parents (receiving support from parents and providing support to parents) in intermediate young adulthood (2005 survey), and in established adulthood (2016 survey). However, parents' and children's gender differences were not identified in the above associations. The study concludes that frequent contact with parents in emerging adulthood is a key factor in establishing intergenerational solidarity with parents from early-to-middle stage of adulthood regardless of parents' and children's gender. (PsycInfo Database Record (c) 2023 APA, all rights reserved).