After a jump in March and in April, the Accountants Confidence Index gave up some of those gains in May.

The ACI, published in partnership with ADP, is a monthly economic indicator that leverages the insights of accountants into the strength and prospects of businesses in the U.S. The 3-Month ACI came in at 55.31 down from the previous month's 55.65. The 6-Month ACI, meanwhile, came in at 57.64, down from last month's 58.14.

Among the index components, panelists were upbeat about their own prospects, but they were very pessimistic about the growth prospects for their large-size business clients.

The ACI is created from a monthly poll of the Accounting Today Executive Research Council, an online community of more than 1,500 tax and accounting professionals.