The start of the new year can find contingent workforce program managers examining their supplier pipelines to see where changes, additions, consolidations or other shifts might be beneficial. SIA reports and lists are good resources to turn to when exploring supplier management options.

SIA’s annual “Largest Staffing Firms in the United States” list is a popular resource for both buyers and suppliers. Enterprise buyers can use it 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 2020 staffing revenue, market share, largest skill segments supplied and other details.

The 2021 annual update, released last month, comprises a record 186 staffing companies that generated $100 million or more in US staffing revenue in 2020; added together, the companies generated $95.1 billion in US staffing revenue.

The US staffing industry continues to be fragmented, with many competitors. The largest firm in the US market, Allegis Group, held 6.8% of the market last year while the combined 186 companies in this report represented 69.9% of the market. Randstad and Adecco were the second- and third-largest firms, accounting for 3.3% and 2.6% market share, respectively.

The top five staffing firms in the US, ranked by estimated 2020 US staffing revenue, are:

Rank Company 2020 US Staffing Revenue ($ million) Market Share Largest segment(s)
1  Allegis Group 9,181 6.8%  IT, Industrial, Engineering
2  Randstad Holding 4,420 3.3%  Industrial, IT, Office/clerical
3  Adecco 3,600 2.6%  Industrial, Office/clerical, IT
4 Express Employment Professionals 3,161 2.3% Industrial, Office/clerical
5  Robert Half International 2,973 2.2% Finance/accounting, IT, Office/clerical


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.

Seventeen firms included in this year’s report did not appear in last year’s version: 22nd Century Technologies, AB Staffing Solutions, Ampcus, Ascend Staffing, Axiom, ConnectRN, IDC Technologies, KellyMitchell Group, LRS Healthcare, Midway Staffing, Net2Source, NuWest Group, Pride Global, ProLink Staffing, Resource Employment Solutions, Trusted Health and Workrise.

Industrial temporary staffing represented the largest segment by revenue with 61 firms on the list, followed by IT with 57 firms. Healthcare was the largest skill segment for 37 firms, including 22 firms that offered travel nursing as their largest segment. On the flip side, the office/clerical and finance/accounting temporary staffing segments were each the largest for three firms, a low number of companies given the size of these segments.

CWS Council can download the full report online.