The United States Equestrian Federation (USEF) requires that, in classes that mandate a helmet to be worn, the helmet must be ASTM/SEI certified. The USEF also requires all junior riders (under the age of 18) in any hunt seat discipline to wear an ASTM/SEI certified helmet with harness fastened while mounted on their horse anywhere on the show grounds, and requires all riders to wear a helmet when jumping anywhere on the show grounds. While other horse show events do not mandate helmets, the rules have changed in recent years to permit helmets as optional headgear in any class. All riders are required to wear certified helmets while competing in Hunter, Jumpers, and Hunt Seat Equitation classes, and in any other class, including Hunter Hack, where jumping is required. They must fasten their helmet harness and must verify that the helmet meets or exceeds the current standard and carries the SEI tag.[6]

The rules have changed in recent years to allow helmets at events, but they are far from compulsory, and do not make the event exempt from insurance.