As the workforce ages, organizations are increasing their efforts to retain retirement-eligible workers to avoid human capital shortages and preserve knowledge reservoirs. Nevertheless, the potential factors and underlying mechanisms relating to the retention of retirement-eligible workers have rarely been examined. The current research investigates how retirement-eligible workers may be retained by the organization through human capital development activities. Specifically, we draw upon the motivated choice framework to investigate the joint implications of individual (i.e., individual growth need) and organizational factors (i.e., climate for developing older workers and age-inclusive climate) for retirement–eligible workers’ training participation and thereby retention. We tested our hypotheses with two samples in the Netherlands. Study 1 utilized the two-wave, multilevel survey data (2015–2018) from the Netherlands Interdisciplinary Demographic Institute Pension Panel Study (N = 3,200 older workers from 409 organizations). We found that individual growth need and climate for developing older workers had positive associations with training participation, which in turn was positively related to older workers’ decision to stay (vs. retire) despite retirement eligibility. In addition, age-inclusive climate amplified the positive relationship between individual growth need and training participation. Study 2 utilized the two-wave Longitudinal Internet studies for the Social Sciences panel data (N = 301 older workers). We replicated result patterns from Study 1 and found that person-organization fit and needs-supplies fit mediated the relationship between training participation and retirement-eligible workers’ intention to stay.