Our paper addresses education and gender differences in the realization of early-life fertility desires, focusing on the role of union formation timing in achieving fertility goals over the life course. In particular, we investigate the effect of first union-postponement on realizing higher parity fertility desires at age 43. While it is known that ‘underachieving’ occurs more often among the higher educated and among those who postpone first marriage and parenthood beyond age 25, it is not yet well understood how the effect of union formation timing on fertility may differ by desired number of children and educational attainment. Using data from the NLSY79, first findings indicate a delay of first marriage and lower incidences of motherhood among college educated women desiring three or more compared to those desiring two children. Also, among the college educated, marrying after age 30 is associated with a sharp decline in motherhood, but not fatherhood.