In this paper we use the 1 July 2004 introduction of the Australian Baby Bonus to identify the effect of family income on child outcomes. We use a difference-in-differences design, comparing test scores for those born either side of the introduction, to those born in the same windows in the years either side. We find no evidence the Baby Bonus improved child outcomes in aggregate, but some evidence of a modest effect for children from disadvantaged backgrounds. Despite manipulation of birth timing around this and other policy changes, there is no clear evidence of lasting effects from this unintended treatment.