State lead abatement mandates require owners of old houses to mitigate lead hazards in the presence of small children. I estimate the effects of these mandates on the housing market and child health using a triple differences strategy that exploits differences by state, year, and housing vintage. The estimates suggest a large fraction of the abatement costs fall on property owners, with house prices for multi-family properties declining by 6.4% and single-family homes declining 4.3%. These effects persist for at least a decade, consistent with low abatement rates. Families with small children bear part of the mandates’ costs, too: after a mandate, these families are 17% less likely to live in old houses, and they pay higher rents for safer homes. Finally, suggestive evidence indicates that the mandates lower the probability of lead poisoning by 25% per year, from an average of 1%. However, plausible estimates of the value of preventing lead poisoning indicate that, for families with small children, the higher housing expenditures exceed the expected value of the mandates’ benefits, which shows that analyzing the impact of these policies on the housing market is crucial for a comprehensive cost-benefit analysis.