In an aging society, the successful transition from work to retirement becomes a major challenge for individuals, organizations, and governments. This chapter aims to explore the relationship between retirement planning and adjustment, and the general assumption according to which planning for retirement leads to positive adjustment outcomes. To do so, first the different trajectories from employment to retirement in terms of well-being are described, and a synthesis of five distinct retiree types is proposed. We then focus on Schlossberg’s (2003) typology, according to which individuals combine several paths across time in retirement. Second, the chapter focuses on retirement planning as the first phase of the retirement process: Its antecedents (i.e., socio-economic, trait, motivational and socio-cognitive, and social variables) and consequences (i.e., financial security, health and well-being, subjective beliefs and expectations, and social life) are reviewed. Third, practical implications for career counselling interventions of retirement planning are proposed. They relate to the Transition to Retirement Questionnaire, identifying more vulnerable groups, and target four main ingredients that reinforce the positive impact of retirement planning on adjustment. Finally, future directions for research on the relationship between retirement planning and adjustment are suggested.