To qualify for the Fastest-Growing US Staffing Firms list, staffing firms must have posted at least $1 million in revenue in 2017 and delivered a compound annual growth rate in revenue of at least 15% between 2017 and 2021. All firms on this list were required to verify revenue. Only organic revenue growth was considered. Revenue was adjusted to remove growth from acquisitions. It was also adjusted for divestitures.

The list is based on staffing revenue, which includes temporary staffing revenue, direct hire, retained search and temp-to-perm conversion fees. Firms with franchised operations included revenue from franchisees. For the purposes of this list, staffing revenue did not include revenue from payrolling, PEO services, MSP fees or pass-through funds, RPO, HRO, outplacement or solutions revenue.

This year’s list may not be directly comparable with lists from previous years because of changes in methodology. For example, some lists from prior years included firms’ payrolling revenue. This year’s list does not.