The policy will be effective immediately at all its venues including the Palace and Turf Club.
New York City Mayor Bill de Blasio "strongly" urged even vaccinated people to start wearing masks indoors. Gov. Andrew Cuomo said unvaccinated transit employees in the metropolitan area would undergo weekly virus testing. But both Democrats on Monday resisted calls to impose new mask or vaccination requirements to counter a rapidly climbing number of new COVID-19 infections.
Last year's events were hindered by unrest and the COVID-19 pandemic.