Economists had forecast an additional 148,000 jobs would be created in the month.
On top of falling short of predictions, the payroll firm revised its estimate for April from 119,000 new jobs to 113,000.
The monthly report, delayed a day by the Memorial Day holiday, anticipates Friday's government report on jobs, which includes private and public sector employment.
ADP said manufacturing businesses lost 2,000 jobs in May, the second consecutive monthly decline. The construction sector, also down in April, lost an additional 1,000 jobs in May the report said.
Firms with fewer than 50 employees added 67,000 jobs in the month, while companies with 51 to 499 employees added 57,000 jobs. Firms with more than 500 workers added 9,000 jobs.
ADP said the financial sector added 8,000 jobs in May, the category adding jobs for the tenth consecutive month.