Temporary Help Services (United States) — NAICS 561320

An investor's primer. NAICS = North American Industry Classification System, the federal code set used to define this industry.

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1. Overview

Temporary help services firms — "staffing agencies" or "temp agencies" — supply workers to other businesses for limited periods. The staffing firm is the legal employer: it recruits, hires, pays wages, withholds taxes, carries the workers on its own payroll, and then bills the client for the hours worked. The client directs the work on site but does not put the worker on its books.[4] That single structural fact — the agency owns the payroll — is what separates this industry from a job board or a headhunter.

The product is flexible labor. Companies use temps to cover seasonal peaks, staff a project with a fixed end date, fill a role while deciding whether to hire permanently, cover absences, or simply avoid adding headcount when the outlook is uncertain. Because temp workers are the easiest labor to add and the first to cut, the industry expands and contracts ahead of the broader economy — economists treat temporary-help employment as a leading indicator of hiring and recessions.[8][9]

Why it matters to an investor. This is a large, cyclical, low-margin, cash-generative service industry. Owners make money on the spread between what they bill the client and what they pay the worker, net of employment costs. Volume moves with the business cycle; margins move with the mix of skills placed (warehouse labor is thin; travel nurses and software engineers are fat). Returns depend far less on headline revenue than on billed hours, gross profit per hour, recruiter productivity, collections, and compliance — because a large share of staffing revenue is simply wages passed through to workers.

Public and private ways in. A handful of global staffing companies trade publicly (ManpowerGroup, Robert Half, Kelly, Kforce, AMN Healthcare, Cross Country Healthcare, Korn Ferry, TrueBlue, HireQuest, BGSF, GEE Group; Europe's Randstad and Adecco run large U.S. operations). But the largest single U.S. staffing firm — Allegis Group — is privately held, as are healthcare-staffing leader Aya Healthcare, IT-staffing leader Insight Global, and Apollo-owned industrial staffer Employbridge.[7] The industry is highly fragmented: over 16,000 firms, most of them small, regional, franchised, or private-equity-backed.[2] So private ownership — buying, building, or franchising an agency, or lending to one — is at least as common a route as owning a share.

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2. What it is and how it's structured

Scope. NAICS 561320 covers establishments that supply workers to clients' businesses for limited periods, where the individuals provided are employees of the temporary help services establishment.[4] It spans general labor and industrial, office and clerical, construction and skilled trades, technical and IT, healthcare, legal, and online staffing, and includes labor pools and personnel suppliers.[4] The two defining features are that the agency is the W-2 employer (W-2 is the U.S. tax form for employees, as distinct from an independent contractor), and that the placement is temporary.

The industry sorts into a few broad occupational lanes. By headcount the mix is roughly 36% industrial (warehouse, light manufacturing, logistics), 24% office/clerical and administrative, 21% professional/managerial, 11% engineering/IT/scientific, and 8% healthcare.[6] By revenue, the picture inverts at the top: the higher-skill lanes (IT, healthcare, professional) generate far more revenue per worker, so industrial and clerical together are about two-thirds of the bodies but under a third of the dollars.[6]

What it explicitly excludes (these are adjacent NAICS codes, not this one):

• 561311 Employment Placement Agencies and 561312 Executive Search Services — recruiters and headhunters who place a worker onto the client's payroll for a fee, and never employ the worker themselves.[4]
• 561330 Professional Employer Organizations (PEOs) — "co-employers" that take over HR, payroll, and benefits administration for a client's existing staff; they don't supply new temporary workers.[4]
• 561210 Facilities Support Services — providing a broader combination of operating staff that run a client's facility.[4]
• 115115 Farm Labor Contractors — agricultural crews.[4]

The boundary matters for investors because trade-press "staffing market" figures often blend temp help with search, placement, and PEO revenue, so headline numbers vary by definition.

Ownership mix. Three tiers. (1) A small number of large, mostly public or foreign-owned multinationals with national and global account relationships. (2) A wide middle of specialist firms — healthcare/travel-nurse agencies, IT staff-augmentation shops, industrial staffers — many owned by private equity. (3) A long tail of thousands of small local and franchised offices. Franchising is a real sub-model: Express Employment Professionals, HireQuest, and Labor Finders run largely on franchisee-operated branches.[7] The federal data do not report a public-versus-private ownership split, and the Small Business Administration's (SBA) $34 million revenue threshold for this code is a government-contracting size standard, not an estimate of market share.[3]

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3. How big it is

Federal statistics (our ground truth):

Note the mixed reference years: receipts, firm count, and the concentration measures in Section 8 are from the 2022 Economic Census, while employment, establishments, and payroll are from 2023 County Business Patterns (CBP).[1][2] A firm can operate many establishments, so the firm and establishment counts are not interchangeable.[1]

Two things stand out. First, payroll (~$177B) is a huge share of revenue (~$326B) — because most of what an agency bills is passed straight through to wages and employment taxes. This is a low-value-add-per-dollar business by design. Second, the employee count is a point-in-time snapshot, and this industry churns like almost no other: the American Staffing Association (ASA, the industry trade body) estimates about 2.2 million temporary and contract workers were on assignment in an average week of 2024, but roughly 11.2 million different people cycled through staffing jobs over the full year.[6] The "stock" is a few million; the annual "flow" is over ten million.

On the undercount question, the caveat runs the other way. Unlike industries dominated by tiny cash operators or by government, temporary help is well captured by federal data: the employers are formal businesses running real W-2 payrolls, exactly what the Census Bureau and Bureau of Labor Statistics (BLS) count best. CBP does exclude the self-employed, businesses without employees or an Employer Identification Number, and most government workers, but those gaps are small here.[1] Two real measurement quirks remain. First, a temp is counted in the staffing industry even though he or she physically works at a manufacturing, retail, warehouse, or hospital client — so 561320 pulls employment out of the client industries where the work is actually done.[28] Second, 561320 captures only the slice of flexible labor that flows through W-2 temp agencies; it excludes the fast-growing adjacent channels — PEO arrangements (561330), independent contractors, and gig platforms — so it understates the true size of America's contingent-work economy. Note also that private trade estimates (Staffing Industry Analysts, or SIA, put the total U.S. staffing market near $184 billion in 2024[5]) are lower than the Census receipts figure; the gap reflects different definitions, timing, and which firms are surveyed. Prefer the federal figures above for the industry itself.

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4. The investable universe

Most temp-staffing revenue sits in private hands, but there is a real public roster. The companies below are access points, not pure plays — most combine temporary staffing with permanent placement, consulting, managed services, or large international operations. Scale is shown as annual revenue (a cleaner size gauge than market value for a pass-through business); these shares are small- to mid-cap and cyclical.

Publicly traded (U.S.-listed):

Foreign-listed with large U.S. operations: Randstad (Euronext Amsterdam: RAND), based in the Netherlands, and Adecco Group (SIX Swiss Exchange: ADEN), based in Switzerland — the two largest staffing firms in the world by billings.[7][22][23]

Major private / other owners:

• Allegis Group — the largest single U.S. staffing firm, privately held; brands Aerotek, Actalent, TEKsystems, Aston Carter, and Allegis Global Solutions.[7][24]
• Aya Healthcare — largest U.S. healthcare staffer, private.[7]
• Insight Global — private-equity-backed IT/professional staffing, consulting, and technology services.[27]
• Employbridge — majority-owned by funds managed by Apollo Global Management; industrial/logistics brands including ResourceMFG, ProLogistix, ProDrivers, Select, RemX, Remedy, Westaff, Hire Dynamics, and Bluecrew.[25]
• Express Employment International — privately held franchisor of Express Employment Professionals; local offices are independently owned franchises.[26]
• Plus Health Carousel and a long list of private-equity-backed regional and vertical specialists.[7]

Bottom line for stock pickers: the pure large-cap temp-staffing play barely exists in the U.S. market. ManpowerGroup, despite ~$18B of revenue, carried a market capitalization of only around $1.5 billion at points in 2025[11] — a reminder that revenue here is mostly pass-through and the equity is thin, cyclical, and small. The richest parts of the industry (Allegis, Aya, Insight Global) are private.

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5. How the money works

The spread is everything. The basic transaction: (1) a client requests workers with specific skills, schedules, and compliance requirements; (2) the agency recruits, screens, hires, and assigns them; (3) the agency pays wages, payroll taxes, benefits, insurance, and related employment costs; (4) the client pays an hourly bill rate, unit rate, or project fee — revenue is essentially hours (or units) multiplied by the bill rate.[17][18] Two numbers define a placement: the bill rate (what the client pays per hour) and the pay rate (what the worker earns). The difference funds the agency's employment costs and profit.

• Markup is the bill rate expressed over the pay rate — typically 30% to 75% for temp/contract placements, occasionally 100%+ for high-cost specialties like travel nursing.[10]
• Burden — the employer costs baked between pay and bill — is large: the employer's share of Social Security and Medicare (FICA), federal and state unemployment taxes (FUTA/SUTA), and workers' compensation insurance, which is why a "1.45x–1.75x" markup is roughly break-even-plus, not pure profit.[10]
• Gross margin (what the agency keeps after paying the worker and burden, as a share of the bill) averages around 25%, but ranges widely: thin (~15–18%) on commodity industrial labor, richer on IT, professional, and healthcare.[10]
• Net margin is slim — commonly 3% to 8% — because branch offices, recruiters, sales staff, insurance, bad debt, and technology eat most of the gross margin.[10]

So the model is high volume, low margin, high operating leverage. A modest change in volume or in the bill-pay spread swings profit hard. In the 2023–2025 downturn, healthcare agencies watched pandemic-era travel-nurse bill rates normalize downward; Cross Country Healthcare, for example, saw revenue fall sharply year-over-year as rates and volumes reset, with gross margin squeezed by spread compression.[16]

Two adjacent revenue lines improve the mix:

• Permanent placement / temp-to-hire conversion fees — when a client hires a temp permanently, the agency collects a one-time fee, often 15–30% of first-year salary.[10] High margin, but volatile and cyclical (it dries up first in a downturn).
• Managed programs. Large clients run their contingent labor through a VMS (vendor management system — software that routes and tracks temp requisitions) overseen by an MSP (managed service provider — a firm, often a staffing company itself, that manages all of a client's staffing vendors). Winning the MSP seat brings scale and stickiness but at lower take rates.

Working capital is the hidden cost. The agency pays workers weekly but collects from clients on 30–60 day terms, so it constantly funds a receivables gap — measured as DSO (days sales outstanding, the average time to collect an invoice). Growth consumes cash; a fast-growing agency can report higher revenue while becoming more dependent on a credit line or invoice factoring. This is why lenders (including business development companies and private-credit funds) are active financiers of the sector, and why balance-sheet strength is a competitive weapon.

Operating metrics to watch (for both public analysis and private diligence): billed hours and active workers; assignment starts and fill rate; bill-rate and pay-rate growth; gross profit per billed hour; gross/contribution margin; temp-to-hire conversion and retention; recruiter productivity and recruiter turnover; client concentration and renewal rates; DSO; workers'-compensation claims and insurance costs; and cash conversion versus borrowing needs.

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6. What drives demand

Temporary staffing demand rises when employers need labor faster or more flexibly than they can hire permanent staff. Common drivers include seasonal peaks, production surges, employee absences, special projects, new facilities, logistics volumes, construction activity, healthcare shortages, and hard-to-fill technical roles.

• The business cycle. Demand tracks gross domestic product (GDP) and hiring. Temps are the marginal, flexible unit of labor — added first in a recovery, cut first in a slowdown. That is why the industry leads the broader jobs cycle by roughly 6–12 months.[8] The most recent cycle shows it plainly: BLS reported that temporary-help employment fell by 159,000 jobs in 2024, and by 624,000 jobs from its March 2022 peak through December 2024.[9]
• The penetration rate — temp workers as a share of total private employment — is the industry's core gauge of structural demand. It sat around 1.56–1.59% in 2025–2026, below the ~2% cyclical peaks, signaling a still-soft market.[8]
• Hiring uncertainty. When employers are unsure about demand, or wary of the cost and commitment of permanent hires (benefits, severance), they lean on temps. Uncertainty is, paradoxically, good for staffing volume even as it is bad for the economy.
• Structural labor shortages in specific verticals — nurses and allied health above all — create demand that persists across the cycle and commands premium bill rates.[15]
• Sector-specific waves: e-commerce and warehouse buildouts (industrial), IT project cycles and digital transformation (tech), and, prospectively, any reshoring of manufacturing.
• Seasonality: retail and logistics peak in Q4; agriculture and hospitality by season.

Investment judgment. The strongest structural supports are employer demand for flexibility, chronic skill shortages, compliance complexity, and the spread of managed contingent-workforce programs. Artificial intelligence may improve sourcing and administrative productivity, but it can equally reduce recruiter headcount and increase price transparency.

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7. Regulation

The industry's defining legal feature is co-employment: because the agency employs the worker but the client directs the work, both can be treated as employers, with overlapping obligations and liabilities. Regulation is a layered mix of federal, state, and local rules.

• Wage-and-hour baseline. The Fair Labor Standards Act (FLSA) sets minimum wage, overtime, recordkeeping, and youth-employment rules; covered nonexempt employees generally earn overtime at 1.5x the regular rate after 40 hours in a workweek.[31]
• Worker classification. Federal law is fact-specific: the Department of Labor's (DOL) economic-reality test asks whether a worker is economically dependent on the employer rather than relying on contractual labels.[31] State laws go further — California's AB5 and its "ABC test" tighten who counts as an employee versus an independent contractor.[32] These mostly bite gig/IC models rather than W-2 temp agencies (whose workers are already employees), but California Labor Code §2810.3 imposes joint liability on clients for a staffing agency's wage and workers'-comp failures — a direct exposure for anyone using temps.[32]
• Worker safety / joint employer. The Occupational Safety and Health Administration (OSHA) treats the staffing agency and the host client as jointly responsible for a temp worker's safety, training, hazard communication, and recordkeeping.[29] The broader "joint employer" standard under the National Labor Relations Board (NLRB — the federal labor-relations agency) has swung with each administration; the NLRB's 2023 rule expanding joint-employer liability was vacated by a federal court in March 2024, leaving the narrower 2020 standard in effect and the question unsettled.[30]
• Anti-discrimination. The Equal Employment Opportunity Commission (EEOC) applies anti-discrimination rules to staffing agencies and their clients; an agency may not accept discriminatory client preferences or make discriminatory referrals.[37]
• Payroll tax. The Internal Revenue Service (IRS) treats temporary staffing as a distinct third-party employment-tax arrangement, making payroll-tax administration and documentation a real operating risk.[36]
• State licensing and temp-worker protection laws — a rising cost. Several states license or register agencies and impose disclosure and fee rules (e.g., Massachusetts).[35] A newer wave grants temps "equal pay" rights: New Jersey's Temporary Workers' Bill of Rights (2023) was the first to require that temp workers be paid no less than comparable direct employees, plus placement-fee caps, mandatory disclosures, and state certification of agencies;[33] Illinois amended its Day and Temporary Labor Services Act (2023–2024) to require equal pay and benefits for temps who work more than 720 hours for the same client in a 12-month period, with a court injunction on the benefits provision lifted in 2025.[34] These laws erode the cost advantage of temporary labor and raise agency compliance burdens.
• Benefits mandates. Under the Affordable Care Act (ACA), staffing firms large enough to be "applicable large employers" must offer health coverage to full-time-equivalent temp workers or face penalties — a real cost given the industry's headcount.[36]
• Also in the mix: immigration and E-Verify obligations, data-privacy and background-screening rules, and state workers'-compensation regimes that price directly into the burden rate.

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8. Competitive dynamics and consolidation

The industry is fragmented and unconcentrated. In 2022 the top four firms held about 18.1% of revenue, the top eight ~25.2%, the top twenty ~37.6%, and the top fifty ~48.8%; the Herfindahl-Hirschman Index (HHI, a standard concentration measure where under 1,500 is "unconcentrated") was just 137.7.[2] With 16,340 firms, no one dominates.[2]

Why so fragmented: barriers to entry are low at the local level — a recruiter with client relationships and a payroll line can open a branch. Competition is local even when the client is national. But scale matters for the things small firms cannot do: national and multi-site accounts, MSP/VMS mandates, insurance and risk absorption, payroll infrastructure, and technology. That splits the industry into national platforms competing for enterprise contracts and thousands of local specialists competing on relationships, speed of fill, and niche expertise.

Consolidation is a constant — but not automatic. Private equity runs roll-up strategies in fragmented verticals (healthcare, IT, industrial), and the public players acquire to add capabilities and geography. Recent examples cut both ways: HireQuest pursued TrueBlue through 2025, ultimately proposing ~$105 million for TrueBlue's PeopleReady industrial-staffing assets after the board rejected earlier whole-company offers;[19] GEE Group bolted on Hornet Staffing as a professional-staffing tuck-in and later divested its Triad light-industrial division.[20] Healthcare staffing in particular has consolidated around a few large platforms (Aya, AMN, Cross Country).[15] But acquisitions can also destroy value through recruiter departures, weak integration, client losses, excess leverage, or working-capital strain, so scale is not a guaranteed advantage.

The disruption overhang. Technology cuts both ways. VMS platforms and client "direct sourcing" tools threaten to disintermediate agencies from routine placements; gig-labor marketplaces (Instawork, Wonolo) compete at the low-skill industrial end; and AI now automates much of the sourcing-and-matching work that recruiters used to bill for. The same tools also let efficient operators run leaner. Whether AI is a margin tailwind or an existential disintermediator is the industry's central open question — a forward-looking judgment, not a settled fact.

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9. Risks

• Cyclicality. Revenue can fall double digits in a downturn because temps are cut first; the 2023–2025 stretch was a genuine staffing recession, with volumes and (in healthcare) bill rates both resetting lower.[5][9][16]
• Thin, fragile margins. With 3–8% net margins,[10] small hits to volume or bill-pay spread erase profit fast; there is little cushion.
• Spread compression. Wage inflation and competition for scarce workers can push pay rates up faster than agencies can raise bill rates.[16]
• Working-capital intensity. Growth burns cash; a credit crunch or a large client's slow payment can strain even a growing firm.
• Client and vertical concentration. Firms over-exposed to one sector (e.g., travel nursing at its pandemic peak) ride that sector's boom-bust.
• Regulatory drift. Every "equal pay for temps" law (New Jersey, Illinois, and imitators) and every expansion of joint-employer liability narrows the cost advantage of temporary labor and raises compliance costs.[33][34][30]
• Legal and safety liability. Wage-and-hour, discrimination, misclassification, joint-employer, and OSHA claims all flow to the agency as the W-2 employer.
• Cybersecurity. Agencies hold large volumes of worker and client data, an attractive target.
• Technological disintermediation. VMS/direct-sourcing and AI could shrink the agency's role in commodity placements.
• Confusing revenue with value. Because so much of the top line is wage pass-through, a firm can grow billings while its spread, cash flow, or compliance quality deteriorates.
• For equity holders specifically: low liquidity and small caps make several of these stocks volatile and cyclical-timing-dependent.

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10. How to invest, and the outlook

Public routes. Direct ownership of the U.S.-listed names — ManpowerGroup (MAN), Robert Half (RHI), Kelly (KELYA/KELYB), AMN Healthcare (AMN), Cross Country Healthcare (CCRN), Korn Ferry (KFY), TrueBlue (TBI), Kforce (KFRC), HireQuest (HQI), BGSF, GEE Group (JOB) — or the foreign majors Randstad (RAND) and Adecco (ADEN) for global exposure with large U.S. operations.[7] These are cyclical, value-style equities: several pay dividends, they tend to trade on forward earnings and on inflection points in the staffing cycle, and the small caps are illiquid. There is no dedicated temp-staffing exchange-traded fund; broad exposure otherwise comes via industrials/business-services funds. When comparing names, compare like with like — separate temporary staffing from permanent placement, consulting, managed services, and international operations, and focus on billed hours, gross profit per hour, pricing, recruiter productivity, collections, cash conversion, client concentration, workers'-comp, and net debt. Enterprise-value-to-normalized-EBITDA (earnings before interest, taxes, depreciation, and amortization) can help, but only after adjusting for the cycle and for wage pass-through; treat dividend yield and share-price multiples as complements to balance-sheet analysis, not substitutes.

Private routes — often where the better economics sit:

• Buy or build an agency, or acquire a franchise (Express Employment Professionals, HireQuest, Labor Finders) for a turnkey brand-and-systems package.[19][26]
• Private-equity roll-ups of regional or vertical specialists (healthcare, IT, industrial) — the dominant M&A pattern in the sector.
• Private credit / factoring. Because agencies constantly fund a payroll-to-collections gap, lending against staffing receivables (through business development companies or specialty-finance lenders) is a recurring, cash-flow-oriented way to participate without owning the cyclicality of the equity.

Private diligence should center on weekly payroll funding, client payment terms, workers'-compensation history, state licenses, assignment-level profitability, worker retention, recruiter dependence, owner and customer concentration, contract terms, and quality of earnings. A local agency can be attractive for a defensible labor-market niche, but vulnerable if one owner or one client controls the relationships.

Near-term drivers and outlook (forward-looking judgment). The industry entered 2025 in a multi-year cyclical trough: the penetration rate remains below prior peaks,[8] temp employment fell through 2024,[9] and healthcare bill rates have largely finished normalizing off pandemic highs.[16] SIA projected the U.S. staffing market to return to roughly +3% growth in 2025 and a firmer rebound into 2026 as hiring recovers.[5] The structural bull case rests on persistent demand for flexible labor, chronic healthcare-worker shortages, and any manufacturing reshoring; the structural bear case is that AI and direct-sourcing tools automate away both the roles being placed and the recruiting function itself. The best businesses combine specialized worker supply, strong client retention, disciplined pricing, reliable collections, low safety/compliance risk, and enough scale to fund technology and national accounts; the weakest grow revenue without protecting spread, cash flow, or worker quality. Watch three signals: the monthly temp penetration rate (labor-cycle direction), bill-pay spreads (margin health), and how fast the leaders convert AI from a cost into a moat.

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Sources

1. U.S. Census Bureau, County Business Patterns 2023, NAICS 561320 (payroll, employment, establishments; methodology and coverage). https://www.census.gov/programs-surveys/cbp.html
2. U.S. Census Bureau, 2022 Economic Census — Concentration of Largest Firms, NAICS 561320 (receipts, firm count, CR4/CR8/CR20/CR50, HHI). https://www.census.gov/programs-surveys/economic-census.html
3. U.S. Small Business Administration, Table of Small Business Size Standards, 2023 (NAICS 561320 = $34.0M receipts; government-contracting standard). https://www.sba.gov/document/support-table-size-standards
4. U.S. Census Bureau, "2022 NAICS 561320 — Temporary Help Services" (definition and exclusions: 561311, 561312, 561330, 561210, 115115). https://www.census.gov/naics/?details=561320&input=561320&year=2022
5. Staffing Industry Analysts, "US Staffing Industry Forecast" (market ~$184B in 2024; +3% 2025; 2026 rebound), 2025. https://www.staffingindustry.com/research/research-reports/americas
6. American Staffing Association, "Staffing Industry Statistics" (2.2M weekly / 11.2M annual employees; occupational mix), 2025. https://americanstaffing.net/research/fact-sheets-analysis-staffing-industry-trends/staffing-industry-statistics/
7. Staffing Industry Analysts, "Largest US/Global Staffing Firms" (Randstad, Adecco, ManpowerGroup; Allegis, Aya, Insight Global, Employbridge; BGSF), 2025. https://www.staffingindustry.com/news/global-daily-news/allegis-aya-and-insight-global-top-sia-list-of-largest-staffing-firms
8. Federal Reserve Bank of St. Louis (FRED), "All Employees, Temporary Help Services (TEMPHELPS)" and SIA monthly US jobs reports (leading-indicator role; penetration rate ~1.56–1.59%), 2025–2026. https://fred.stlouisfed.org/series/TEMPHELPS
9. U.S. Bureau of Labor Statistics, Monthly Labor Review, "Total Nonfarm Employment Growth Continues to Slow in 2024" (temp-help −159,000 in 2024; −624,000 from March 2022 peak through December 2024), 2025. https://www.bls.gov/opub/mlr/2025/article/total-nonfarm-employment-growth-continues-to-slow-in-2024.htm
10. Industry practitioner sources on staffing economics — Lone Oak Payroll / USA Staffing Services, "Staffing Agency Profit Formula: Bill Rates, Markup & Margin" (markup 30–75%; ~25% gross margin; 3–8% net; direct-hire fees 15–30%; burden rate), 2025–2026. https://www.loneoakpayroll.com/newsitems/staffing-agency-profit-formula-how-to-mark-up-bill-rates/
11. ManpowerGroup, 2024 Annual Report / Form 10-K (revenue ~$17.9B); market capitalization via Macrotrends (~$1.5B at 2025 lows). https://www.macrotrends.net/stocks/charts/MAN/manpowergroup/market-cap
12. Robert Half Inc., FY2024 results (total revenue ~$5.8B; Protiviti ~36%), SEC filings. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000315213&type=10-K
13. Kelly Services Inc., FY2024 Form 10-K (revenue ~$4.3B). https://ir.kellyservices.com/
14. Korn Ferry, FY2024 results (fee revenue ~$2.8B), SEC filings. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000056679&type=10-K
15. AMN Healthcare Services Inc., FY2024 results (revenue ~$3.0B; healthcare-staffing landscape), SEC filings. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000903571&type=10-K
16. Cross Country Healthcare, "Fourth Quarter and Full Year 2024 Financial Results" (revenue ~$1.8B; bill-rate normalization; spread compression), 2025. https://www.businesswire.com/news/home/20250304948294/en/
17. TrueBlue Inc., FY2024/2025 Form 10-K (revenue ~$1.6B; PeopleReady). https://investor.trueblue.com/sec-filings/
18. Kforce Inc., FY2024 Form 10-K (technology and finance/accounting staffing; revenue ~$1.5B). https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000930420&type=10-K
19. StreetInsider / Seeking Alpha, "HireQuest offers $105 million for TrueBlue staffing segment" (HQI franchise model), 2025. https://seekingalpha.com/news/4591824-trueblue-jumps-12-on-hirequests-105m-proposal-to-buy-staffing-segment
20. GEE Group Inc., FY2025 Form 10-K (professional contract staffing; Hornet Staffing acquisition; Triad divestiture). https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000040570&type=10-K
21. BGSF Inc., FY2024 Form 10-K (property staffing and professional/IT staffing segments). https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001474903&type=10-K
22. Randstad N.V., Annual Report 2025. https://www.randstad.com/investor-relations/
23. Adecco Group AG, Annual Report 2025. https://www.adeccogroup.com/investors/
24. Allegis Group (Aerotek, Actalent, TEKsystems, Aston Carter, Allegis Global Solutions), corporate materials. https://www.allegisgroup.com/
25. Employbridge (majority-owned by Apollo Global Management; ResourceMFG, ProLogistix, ProDrivers, Select, RemX, Remedy, Westaff, Hire Dynamics, Bluecrew), company news. https://www.employbridge.com/
26. Express Employment International (privately held franchisor; Express Employment Professionals), company news. https://www.expresspros.com/
27. Insight Global (private-equity-backed IT/professional staffing), corporate materials. https://insightglobal.com/
28. U.S. Bureau of Labor Statistics, "Manufacturers' Outsourcing to Temporary Help Services: A Research Update" (agency workers classified in staffing even when working at client sites), 2017. https://www.bls.gov/osmr/research-papers/2017/ec170010.htm
29. Occupational Safety and Health Administration, "Protecting Temporary Workers" (staffing agency and host jointly responsible). https://www.osha.gov/temporaryworkers
30. Foster Garvey / Congressional Research Service, "NLRB Joint Employer Rule vacated March 2024; 2020 standard in effect," 2024. https://www.foster.com/newsroom-alerts-what-employers-should-know-about-the-NLRBs-new-joint-employer-rule
31. U.S. Department of Labor, "Wages and the Fair Labor Standards Act" and Fact Sheet 13, "Employment Relationship Under the FLSA" (overtime after 40 hours; economic-reality test). https://www.dol.gov/agencies/whd/flsa/
32. California Franchise Tax Board & Rogers Joseph O'Donnell, "Worker Classification and AB 5 / the ABC Test" and Labor Code §2810.3 joint liability, 2019–2024. https://www.ftb.ca.gov/file/business/industries/worker-classification-and-ab-5-faq.html
33. Ogletree Deakins / Lexology, "New Jersey Temporary Workers' Bill of Rights" (equal pay for temps; fee caps; certification), 2023. https://ogletree.com/insights-resources/blog-posts/new-jersey-temporary-worker-pay-transparency-law-takes-effect/
34. Jackson Lewis / Illinois Department of Labor, "Illinois Day and Temporary Labor Services Act" (equal pay and benefits after 720 hours in 12 months; injunction lifted 2025), 2023–2025. https://www.jacksonlewis.com/insights/illinois-amends-temp-worker-law-boosting-employer-obligations
35. Commonwealth of Massachusetts, "Information for Staffing Agencies" (licensing/registration; temp-worker disclosure and fee restrictions). https://www.mass.gov/info-details/information-for-staffing-agencies
36. Internal Revenue Service, "Third-Party Payer Arrangements for Employment Taxes" (IRM 5.1.24) and ACA applicable-large-employer coverage guidance. https://www.irs.gov/irm/part5/irm_05-001-024r
37. U.S. Equal Employment Opportunity Commission, "Coverage of Employment Agencies" (anti-discrimination duties of staffing agencies and clients). https://www.eeoc.gov/employers/coverage-employment-agencies