["Journal of Policy Analysis and Management, Volume 45, Issue 4, Fall 2026. ", "\nABSTRACT\nDespite governments’ efforts to raise fertility through family‐support policies, birth rates continue to decline in high‐ and middle‐income countries. Some policies designed for other purposes, however, may function as implicit childcare subsidies. This article examines the impact of reducing such support on fertility by exploiting a large‐scale reform in Spain that shortened the elementary school day, shifting from full‐day to morning‐only sessions. Using provincial‐level data from 1981 to 2016 and a synthetic difference‐in‐differences identification strategy, I find that the reform reduced the total fertility rate by 0.12 children per woman and delayed maternal age at first birth by approximately 4 months. The delay is significantly larger in provinces with weaker pre‐reform female labor market integration, although fertility declines are similar across labor market contexts. These findings suggest that removing an implicit childcare subsidy increased the cost of childbearing, with fertility timing particularly sensitive to local labor market conditions.\n"]