--- - |2+ Objective We address the impact of policy intervention in youth tennis targeted at mitigating the influence of labor market‐persistent relative age effects known to exist in age‐grouped cohorts of students and athletes. Methods We take advantage of a natural experiment in policy implementation in U.S. youth tennis using a difference‐in‐difference‐in‐difference framework to identify effects among players born early and late in the year at the professional level using data from 1990 through 2015. Results Estimations reveal that the policy was successful in improving relative performance for U.S. men's tennis players born late in the year; however, there was no apparent effect on rankings for women. Conclusion We propose that while policy can have effects at the professional level, policy prescriptions that depend on physical or mental maturity may differ depending on sex or gender and require specificity in structure for various groups. - 'Social Science Quarterly, Volume 99, Issue 4, Page 1496-1509, December 2018. '