Companies have a vested interest in keeping their employees happy. Studies show that employee satisfaction is linked to performance, which permeates through every aspect of a business and can mean the difference between success and failure. While employee satisfaction should be the cornerstone of every serious company’s business model, only a handful of businesses excel at maintaining high employee morale.

Based on employee reviews posted on Glassdoor, an online platform for former and current employees to review companies, 24/7 Wall St. identified the best American companies to work for. Out of a universe of hundreds, only 18 large companies received a score of more than 4 out of 5 stars.

In an interview with 24/7 Wall St., Sarah Stoddard, community expert with Glassdoor, listed the factors that have the greatest impact on employee satisfaction. “Glassdoor research has found the top three indicators of employee satisfaction are career opportunities, trust in senior leadership, as well as culture and values,” Stoddard said.

In keeping with those findings, employee testimony suggests most companies on this list offer growth and development opportunities, have trusted and respected chief executives, and cultures described as fun, motivating, and supportive.

Half of the companies on this list are technology and software firms based on the West Coast. The remaining companies include staffing agencies, management consulting firms, and grocery stores.

This is not a Glassdoor commissioned report.

Click here to see America’s best companies to work for.
Click here to see our detailed findings and methodology.