Standards for helmet protection in the United States have traditionally fallen into two categories, government standards, such as those mandated by the CPSC (U.S. Consumer Product Safety Commission), and voluntary, or industry standards.

Organizations such as the American Society for Testing and Materials (ASTM) or the National Operating Committee on Standards for Athletic Equipment (NOCSAE) have determined voluntary standards for helmets.

The CPSC has mandated since March of 1999 certain standards for bicycle riding helmets manufactured for sale in the U.S. Other helmet standards for sports such as baseball, football, hockey and lacrosse have been determined by the NOCSAE and ASTM. In 1973 the NOCSAE standard for football helmets was developed. The NOCSAE standard for baseball helmets was first published in 1981 and first tested to this standard in 1983. The standards and their testing have been revised over the last twenty years.

The NCAA and the NFHSA (National Federation of State High School Associations) mandate that helmets for football, baseball batters, and lacrosse meet the NOCSAE standards. The NOCSAE and ASTM helmet standards attempt to measure the injury producing linear and angular accelerations resulting from head impact. (Tests include dropping a helmet in free fall and measuring the helmet's ability to attenuate the kinetic energy imparted during the test and linear projectile impact tests. The NOCSAE tests require a series of impacts in specific locations. The results are reported in severity index (SI) units. The ASTM data are usually provided in peak g levels. The pass-fail criterion may vary with headgear type but is normally 300 g or below registered inside the headform in a drop test.)

To meet some safety standards, a baseball is shot 60 mph at close range at a batting helmet. Helmets must resist impact and damage as measured through a severity index. (See NOCSAE standards for Baseball Batter's Helmet and Baseball Catcher's Helmet - NDO22, NDO24.)