Increasingly, older adults are redefining retirement by combining part-time employment with pension benefits, that is, becoming ‘working retirees’. This trend highlights socio-economic inequalities: some working retirees use part-time employment as a bridge to full retirement, while others must remain employed to prevent old-age poverty. However, little is known about how these work-retirement transitions unfold over time or the socio-economic factors that shape them. This knowledge gap is problematic because understanding the socio-demographic influences on these trajectories is essential for addressing inequalities in later-life employment and retirement security. This study examines transitions from work to retirement by following individuals from their 50s into their 70s and analysing the socio-demographic factors that differentiate these trajectories. It identifies the various pathways that older workers take when exiting the labour force and analyses how prior life course factors – including education, occupational status, career field, civil status, number of children and disposable income – predict the likelihood of following each work–retirement trajectory. The results reveal two distinct work–retirement trajectories: one reflects status maintenance, with higher income and education, white-collar and often men; the other reflects financial necessity, with lower income, children at home, no partner and often women. More advantaged working retirees experience greater employment changes in late life, highlighting the diversity of late-life careers. These findings suggest a broader range of extended work–life pathways than previously recognized and emphasize the need for policies that account for gendered and economic disparities in work and family responsibilities to ensure equitable and sustainable retirement transitions.