France and the United Kingdom represent two contrasting institutional models for the integration of employment and motherhood, respectively the 'universalistic' regime type that offers subsidized child-care and maternity-leave benefits to women at all income levels, and the 'means-testing' regime type that offers predominantly income-tested benefits for single mothers. Using the two countries as comparative case studies, the authors develop and test the hypothesis that the socio-economic gradient of fertility timing has become increasingly mediated by family policy. They hypothesize and find increasing polarization in age at first birth by pre-childbearing occupation between the 1980s and 1990s in the U.K. but not in France. Early first childbearing persisted in the U.K. only among women in low-skill occupations, while shifts towards increasingly late first births occurred in clerical/secretarial occupations and above. Increases in age at first birth occurred across all occupations in France, but this was still much earlier on average than for all but low-skill British mothers.