As contingent workforce program managers examine their supplier pipelines to see where changes, additions, consolidations or other shifts might be beneficial, SIA reports and lists are good resources.

SIA’s annual “Largest Staffing Firms in the United States” list is one such tool, which enterprise buyers can use to review current supplier partners that may be included or to identify some that they may be considering engaging with. It saves time by providing a big picture in one report with vetted information for each firm including estimated 2021 staffing revenue, market share, largest skill segments supplied and other details.

The 2022 update, release last month, comprises 225 companies that had US staffing revenue of $100 million or more in 2021. That compares to 186 in last year’s report.

“While some industries experienced disruptions in 2021, the staffing industry instead flourished in an environment of record demand,” said Timothy Landhuis, VP of research at SIA. “We salute the hard work and resourcefulness of the staffing firms that appear on this year’s list, that were able to deliver at record scale, and that altogether generated an extraordinary $135 billion in staffing revenue.”

Allegis Group, based in Hanover, Maryland, ranked as the largest US staffing firm as it had on last year’s list. However, this year’s list featured a new firm in the No. 2 spot — Aya Healthcare, a San Diego-based healthcare staffing firm, up from No. 14 last year.

IT temporary staffing was the largest revenue segment for 64 firms, or 38% of the total 225 listed. Industrial staffing was cited by 61 firms, or 27%, as their largest revenue source. Healthcare staffing was the largest revenue segment for another 61 firms.

California was home to the US headquarters of 23 firms on the list. It was followed by Georgia, headquarters for 20, and Florida, headquarters for 19.

Staffing revenue in the report includes temporary staffing, direct hire and retained search as well as temp-to-hire conversions. It does not include other types of workforce solutions ecosystem revenue such as MSP, RPO, payrolling or outplacement.

Revenue figures in the report represent SIA’s best estimation based on available information at the time of publication. The accuracy of estimates may vary depending on multiple factors, including firms’ willingness to provide or confirm information about their operations.

The full “Largest Staffing Firms in the United States: 2022 Update” report is available for SIA’s corporate and CWS Council members.