More than two-thirds of employers favor repeal of the Affordable Care Act’s employer mandate, citing the cost and administrative burden of showing they are in compliance, according to a new survey.

The benefits consulting firm Mercer said repeal of the mandate — with 70% in favor — came in second among the changes employers would like to see in the ACA, behind only repeal of the excise tax (85% in favor).

“It’s not because they don’t want to offer coverage. It’s because proving that they offer coverage is so much work,” Tracy Watts, Mercer’s leader for health reform, said in a news release.

The deadline for reporting to the IRS about coverage in 2015 was extended from January to June, and at this point virtually none of the 644 survey respondents believe they will be liable for the “a” assessment — meaning they offered coverage to substantially all employees working 30 or more hours per week.

Only 8% of employers thought they might be at risk for the “b” penalty — meaning that some of their employees might qualify, and obtain, subsidized coverage on the exchange because their employer’s plan did not offer affordable contributions or meet minimum plan value requirements.

“This suggests that penalties are not going to amount to a huge source of revenue,” said Beth Umland, Mercer’s research director for health and benefits. The Congressional Budget Office has estimated that employer penalties would raise $9 billion in revenue in 2016.

But when asked about the impact of the ACA on their organization, 20% of respondents said they have experienced higher cost and 29% reported making unwanted plan changes to avoid excise tax liability. At the same time, 84% said the additional administrative burden has had a significant impact — and 51% describe it as “very significant.”

“More than half of Americans already get their health insurance from their employer, and three out of four workers are satisfied with their health benefits,” Watts said. “Under play or pay, employers have had to modify their plans, track worker hours, manage eligibility and report coverage to prove they are doing something they have been doing all along.”