Given theoretical premises, gender wage gap adjusted for individual characteristics is likely to vary over age. We extend DiNardo, Fortin and Lemieux (1996) semi-parametric technique to disentangle year, cohort and age effects in adjusted gender wage gaps. We rely on a long panel of data from the German Socio-Economic Panel covering the 1984-2015 period. Our results indicate that the gender wage gap increases over the lifetime, for some birth cohorts also in the post-reproductive age.