This article contributes to the literature on early retirement transitions by testing a line of explanations of this phenomenon in a specific context of public sector employment. It utilizes waves 2006 and 2007 of a longitudinal data set of employment histories of Polish teachers (SIO). Standard structural explanations of early retirement transitions, i.e. labor force restructuring and devaluation of human capital of older workers do not find support in the data. Multilevel logistic regression models show instead that the considerable variance in early retirement risks found in the data can to some degree be explained by labour mobility of prime aged teachers, supporting the thesis of a labor market as generational figuration. The analyses identify two early emploment groups among Polish teachers: 49-54, and 55-59 year olds. Whereas retirement transitions in the younger group are to a greater extent attributable to individual pull factors (like work commitment), regional variation plays a greater role in the older "early retirees" group indicating higher risks of involuntary early retirement in this group.