Using data from the Fragile Families and Child Wellbeing Survey (N = 2,954), a birth cohort study, this work examines how gains in earnings and income are associated with marriage and subsequent childbearing for low-income couples. Using change models, results indicate that positive changes in earnings, controlling for baseline levels of earnings, were associated with greater odds of marriage. Cohabiting couples who became poor were associated with a 37% decrease in marriage likelihood. Neither earnings nor income was affiliated with additional fertility. Results are consistent with the Financial Expectations and Family Formation theory, which posits that positive economic circumstances are necessary for marriage, but are not associated with subsequent childbearing.