BACKGROUNDWhile a striking rise in shared physical custody after divorce has been observed in Wisconsin and some European countries, the same trend in shared custody has not been documented in US national data. OBJECTIVEWe provide new evidence on the time trend in shared physical custody after divorce in the United States. METHODSWe use eight waves of data from the Current Population Survey -Child Support Supplement to estimate logit models and conduct a formal decomposition. RESULTSThe likelihood of shared physical custody after divorce more than doubled in the United States from before 1985 until 2010-2014, from 13% to 34%. Non-linear probability (logit) models show that non-Hispanic Whites and more advantaged individuals are more likely to report shared physical custody. Both sequential multivariate models and a more formal decomposition show that the increase cannot be explained by changes in the characteristics of those divorcing; rather we find that several characteristics become more strongly associated with shared physical custody over time. CONCLUSIONSOur results suggest that shared physical custody is increasing in the United States as a whole, and this increase appears to reflect changing norms and policies that favor shared custody. These changing patterns have important implications for children's living