Is sexual harassment training mandatory?

Sexual harassment training is recognized as an excellent practice standard for any employer in all 50 U.S. states. In fact, the U.S. Supreme Court has stated that for a company to reduce liability for harassment claims it must train employees and supervisors, require employees to report incidents of harassment, thoroughly investigate all reports and take corrective action when necessary. However, except for a few states, sexual harassment training is recommended rather than required.
Currently, California, Connecticut and Maine are the only three U.S. states that require employers to provide periodic sexual harassment training to supervisors and/or employees. Training is generally required to include information and practical guidance on federal and state sexual harassment laws, as well as the prevention of   sexual harassment and its disciplinary consequences. These states require training to be presented by knowledgeable and experienced educators and provide practical examples that show supervisors how to prevent sexual harassment, discrimination, and retaliation.