The Affordable Care Act’s employer mandate on large businesses barely had an impact on enrollment in employer-sponsored health plan enrollment in the past year, according to a new survey released by Mercer, a human resources consulting firm.

Between 2014 and 2105, employers reported very little change regarding the average number of full- and part-time workers enrolling in employer-sponsored health plans. The survey of 572 large employers found that most companies already met the ACA’s employer mandate requirements.

The Mercer survey also provided evidence that the ACA does not lead to companies dropping health coverage altogether, contrary to critics’ predictions when the law was enacted. Only 3 percent of the companies surveyed reported that they were likely to terminate their plans within the next five years. Employers also reported that some employees were opting out of employer-based coverage to enroll in more affordable Medicaid plans in expansion states.