We study the fertility effects of guaranteed minimum income (MI) programs using Italy’s Reddito di Cittadinanza (RdC), a national income floor introduced in 2019. Using administrative social security microdata and a Regression Discontinuity Design, we find that the RdC had no aggregate effect on fertility but increased childbearing by 18% over two years in Southern Italy, where economic insecurity is higher and gender norms more traditional. The effect appears driven not only by higher income but also by greater economic stability. These results suggest that MI schemes—though not designed with pronatalist intent—can shape fertility in economically disadvantaged settings.