Against the backdrop of demographic change and the pluralisation of living arrangements, the article focuses on repartnering after widowhood, divorce and separation in older age in Germany. While theoretically framing repartnering as a lifecourse transition, the question arises of how later-life relationships form in relation to gender- and ageing-specific as well as structural and processual dimensions. Since previous research indicates that there are gender-specific patterns when repartnering in older age which differ from repartnering in middle age, the article explicitly accounts for gendered ageing and attitudes towards ageing. Using data from the German Ageing Survey (1996–2017), longitudinal hybrid panel regressions are modelled for 3,653 respondents, 11,628 observations and 179 new relationships. I propose to understand within-effects as processual and between-effects as structural dimensions of repartnering. The results for the structural dimensions show that the likelihood of repartnering is higher for men and for individuals with more negative attitudes towards ageing. The results for the processual dimensions show how repartnering becomes less likely the older one gets and the more positive one's attitudes towards ageing become. The interaction term for gender and ageing shows that ageing has a stronger influence on the likelihood to repartner for women than for men. Additionally, the findings reveal a difference between forms of singlehood: in the short term, repartnering is less likely for divorced or separated individuals than for widowed individuals, whereas the opposite effect shows in the long term. In sensitising the lifecourse perspective with gender- and ageing-specific concepts and analytically separating processual and structural dimensions, this article demonstrates the importance of gendered ageing and of the linkage between relationship transitions. Applying hybrid panel models to lifecourse transitions in older age reveals the processual dynamic and structural embeddedness of repartnering in older age.