Fortune has released its 21st annual list of 100 Best Companies to Work For. There are five hotel companies on the list: Kimpton Hotels & Restaurants (No. 6), Hyatt (No. 9), Hilton Worldwide (No. 33), Marriott International (No. 35), and Four Seasons Hotels and Resorts (No. 99).

Great Place to Work U.S. measures companies on the following characteristics: Executive team effectiveness, innovation, people-focused programs, and Great Place to Work For All. In a Great Place to Work For All, employees report high levels of trust, credible and respectful leadership, pride in the work, and camaraderie. Great Place to Work U.S. also looks to see that employees consistently experience the great workplace, regardless of who they are or what they do. Each company is scored on analysis of anonymous employee responses to more than 50 survey questions on the Trust Index Survey, together with an evaluation of company programs and practices as measured through a Culture Audit assessment.

More than 315,000 employees provided feedback to determine the winners of the 2018 list. To be considered, companies needed to have at least 1,000 employees and receive enough survey responses to achieve a 95 percent confidence level with no more than a 5 percent margin of error.