All Other Support Services (NAICS 561990): An Investor's Primer

1. Overview

"All Other Support Services" is the catch-all bin at the bottom of the U.S. business-services classification system. The North American Industry Classification System (NAICS) — the standard code set the federal government uses to group businesses — assigns code 561990 to establishments that provide day-to-day support to other organizations but that do not fit any of the named support-service categories above it.[1] It is a residual category, not a single product market. In practice it is a grab-bag of unrelated small trades: document shredding, physical inventory counting, retail merchandising and in-store sampling, auto repossession, highway work-zone flagging and traffic control, swimming-pool cleaning, independent auctioneering, contract meter reading for utilities, coupon processing, bottle-redemption centers, lumber grading, and commercial diving done on a contract basis.[1]

Why it matters to an investor: individually these niches are small, but they share an attractive economic shape — recurring, contracted, low-capital, labor-based services that other businesses would rather outsource. That has made several of them favorite hunting grounds for private-equity (PE) "roll-ups" (buying many small operators and merging them into one larger company). The flip side is that this is not a place to buy a single "pure-play" stock: no public company's business is "All Other Support Services." Public-market investors get exposure only in fractions — a shredding line buried inside a records or waste company, a merchandising arm inside a marketing-services firm, or an auction business classified in a different code. Private investors, by contrast, can own these businesses directly through acquisitions, PE platforms, private credit, and buy-and-build strategies — which is exactly what the consolidators are doing.

2. What it is and how it's structured

Scope. Code 561990 is defined by exclusion: it captures organizational support services except the ones with their own codes.[1] Representative in-code activities include:

• Document/paper shredding and secure information destruction
• Physical inventory-taking (counting a retailer's or warehouse's stock) and related retail merchandising/store-reset work
• Repossession services (recovering collateral for lenders)
• Highway work-zone traffic control and flagging
• Swimming-pool cleaning and maintenance
• Independent auctioneers (who sell on someone else's premises)
• Contract meter reading for utilities
• Lumber grading, bartering services, coupon processing, bottle exchanges, float decorating, and contract diving[1]

What it excludes (and where those go). The adjacent NAICS codes matter because they siphon off most of the recognizable "support" businesses: office administrative services (561110), facilities support (561210), employment/staffing services (5613), business support such as call centers and billing (5614), travel arrangement (5615), security and investigation (5616), services to buildings and dwellings such as janitorial and landscaping (5617), packaging and labeling (561910), and convention and trade-show organizing (561920).[1] Three easy confusions: pool-supply retail and distribution (Pool Corp, Leslie's) sits in wholesale/retail codes — only the cleaning service is in 561990; large salvage-auto auction platforms are generally coded as motor-vehicle dealers (e.g., NAICS 441228), not as auctioneers;[11] and customs brokerage — which some databases file near this code — is properly classified under freight-transportation arrangement, NAICS 488510.[15]

Ownership mix. The industry skews toward very small, owner-operated firms — a single repo truck, a two-person pool route, a solo auctioneer — with a thin layer of larger regional and PE-backed consolidators on top. Employer establishments average roughly 14 workers each (173,815 employees across 12,567 establishments).[3] There are essentially no large public companies operating primarily in this code, and the federal statistics carry no legal-form breakdown, so there is no reliable numeric split between public firms, private firms, sole proprietors, and in-house operations.

3. How big it is

Federal statistics for the employer portion of the industry:

The Small Business Administration (SBA — the federal agency that defines what counts as a "small business" for programs and contracting) sets the size ceiling for most of these activities at $16.5 million in average annual receipts.[4] Since revenue per firm averages only about $2.8 million, the overwhelming majority of firms are, by the government's own definition, small businesses.[2][4]

The undercount caveat — important here. These federal figures count only employer businesses (firms with payroll). This industry is dominated by nonemployer operators — sole proprietors and single-person firms — who fall outside County Business Patterns and the Economic Census receipts table entirely, along with government and in-house work done inside retailers, utilities, and municipalities. The federal file contains no nonemployer, government, or in-house estimate, so the omitted portion cannot be quantified precisely. The direction is clear, though: third-party business directories list roughly 31,000 active companies in the code,[5] and swimming-pool service alone (under a broader definition) is estimated at around 125,000 businesses nationally,[6] versus only ~12,600 employer establishments in the official count.[3] Treat the $29.7 billion employer figure as a floor; the true operator population and total economic activity are materially larger and even more fragmented.

4. The investable universe

There is no pure-play public company in NAICS 561990. Public exposure is indirect and partial — a segment or line item inside a larger, differently-classified company. The most relevant listings:

REIT = real estate investment trust, a company that owns income-producing property and passes most profits to shareholders. Because none of these is a clean read on the industry, the realistic public route is diversified exposure to a theme — shredding/records (IRM, WM), auctions (RBA, CPRT), or retail field-execution (ADV, SGRP) — understanding that 561990 is a minority of each.

Customs/trade-support adjacency (off-code). Some classifications lump cross-border trade support near this bin, but customs brokerage is properly NAICS 488510, not 561990.[15] For completeness, the customs-capable public names are the pure customs broker Expeditors International (NASDAQ: EXPD — customs brokerage and other services were ~36% of 2024 revenue)[14] and the diversified logistics majors UPS (NYSE: UPS), FedEx (NYSE: FDX), and C.H. Robinson (NASDAQ: CHRW), which offer customs brokerage inside much larger operations. Treat these as adjacent, not in-code.

Private and other owners — where most of the industry actually lives:

• Shredding / information destruction: Iron Mountain and Shred-it (now WM) at the top; below them, many private NAID-certified regional shredders and records firms. The secure-shredding sub-market alone is estimated at roughly $3 billion in the U.S.[7]
• Inventory counting / retail merchandising: WIS International (inventory counting, store setup, remodels, space mapping)[18] and RGIS (inventory and data collection) are the two dominant counters; WIS acquired RGIS's former U.S. and Canadian operations.[19] Acosta Group is a large field-sales and merchandising operator that acquired the CROSSMARK and Product Connections businesses from WIS in 2024.[20][21]
• Traffic control / work-zone safety: two large PE-backed consolidators — AWP Safety (backed by Kohlberg & Co.) and RoadSafe Traffic Systems (backed by Investcorp and Trilantic) — plus hundreds of local flagging firms.[16]
• Repossession: highly fragmented single-truck agencies coordinated by "forwarding" companies (Resolvion, MVTRAC, PAR North America) that route lender assignments to local recovery agents.[17]
• Pool service, auctioneering, contract meter reading (e.g., Olameter[23]): thousands of small independents, mostly nonemployer or single-branch firms.
• Customs/trade (adjacent): privately held brokers such as A.N. Deringer sit just outside the code in 488510.[22]

The ultimate PE sponsors of several private operators are not consistently disclosed in public materials.

5. How the money works

These are labor-and-route businesses, not capital-intensive ones. The economics that matter:

• Contracted, recurring revenue. The best niches sell repeat service under contract — a shredding console emptied on a schedule, a pool cleaned weekly, meters read monthly, a store reset each cycle. Pricing is typically per-visit, per-console, per-count, per-pound, an hourly/daily field rate, or a fixed monthly fee; some work is cost-plus.[12] Recurring route density (many customers close together) is the key unit-economics driver: the more stops per truck-mile, the higher the margin.
• Labor utilization. Because the main cost is field labor plus vehicles/fuel, insurance, and technology, profitability turns on keeping crews busy (billable hours and jobs per crew per day), on task accuracy and rework rates, and on wage costs. Average pay in the code is about $56,900 a year, so modest wage inflation moves margins directly.[3] The ability to pass wage and travel inflation through to customers is central.
• Asset-light, but working-capital-sensitive. Low fixed-asset needs produce steady free cash flow — exactly why PE roll-ups favor these trades — but payroll often precedes customer payment, so billing speed and collection days matter.
• Project-linked variants. Some sub-segments track a customer's own spend rather than a subscription. Work-zone traffic control is a line item on construction jobs — typically a few percent of project value — so its revenue rises and falls with road-building and utility work.[24] Repossession volume tracks lender charge-offs; independent auctioneering earns a commission ("buyer's/seller's premium") on gross auction proceeds.

For this industry, field productivity and contract retention are the useful lenses — not factory capacity utilization, same-store sales, or other metrics from asset-heavy sectors. The federal file carries no sector-wide margin, utilization, churn, or input-cost data.

6. What drives demand

Demand is a bundle of unrelated drivers, one per niche:

• Outsourcing appetite underlies all of it: companies increasingly hand non-core chores — inspection, counting, field execution, administrative tasks — to specialists.
• Regulation and data-privacy rules drive secure shredding (see Section 7).
• Credit conditions drive repossession: rising delinquencies and charge-offs mean more recovery assignments. U.S. vehicle repossessions rose sharply into the mid-2020s (an estimated ~1.9 million vehicles recovered in 2024) as auto-loan stress climbed.[17]
• Infrastructure and construction spending drive work-zone traffic control; federal highway funding and utility/broadband build-outs are direct tailwinds.[24]
• Retail and warehouse activity, plus omnichannel complexity, drive physical inventory counting and store-execution work — retailers still need accurate independent counts, shelf resets, and shrinkage control.[18]
• Housing and pool stock, plus sunbelt migration, drive pool service.[6]
• Cross-border trade complexity supports the adjacent customs/trade-support slice.[14]
• Technology cuts both ways: mobile data capture, AI (artificial intelligence), and better scheduling raise productivity and auditability, but can also reduce demand for low-skill manual work.[18]

7. Regulation

There is no single regulator for the code; each activity carries its own rules, and NAICS 561990 itself is only a statistical classification, not a license.

• Secure shredding is effectively mandated by data-protection law: the federal Fair and Accurate Credit Transactions Act (FACTA) Disposal Rule, the Health Insurance Portability and Accountability Act (HIPAA, governing medical records), and the Gramm-Leach-Bliley Act (GLBA, financial-data privacy) all require secure destruction of sensitive records — turning shredding from optional to compulsory for many businesses. Industry certification comes from NAID (the National Association for Information Destruction).
• Repossession is licensed and closely regulated at the state level and overseen federally through consumer-protection law enforced by the Consumer Financial Protection Bureau (CFPB); "breach of the peace" rules limit how agents may recover vehicles.
• Traffic control must follow the federal MUTCD (Manual on Uniform Traffic Control Devices) and state Department of Transportation (DOT) prequalification standards; DOT prequalification is itself a barrier to entry that can raise a firm's value.[24]
• Retail sampling, demonstrations, and endorsements must be truthful and substantiated under the Federal Trade Commission (FTC) rules; the FTC updated its Endorsement Guides in 2023.[26]
• Auctioneering requires a state auctioneer license in many states.
• Labor-intensive operators everywhere face wage-and-hour, safety, and worker-classification rules: the Fair Labor Standards Act (FLSA) governs employee protections, and the employee-versus-independent-contractor line remains a live compliance issue.[27] Utilities/meter reading, diving, and pool-chemical handling also carry occupational-safety (OSHA — Occupational Safety and Health Administration) and, for pools, local health-code obligations.
• Customs brokerage (adjacent) is the most clearly regulated neighboring activity: brokers must comply with U.S. Customs and Border Protection (CBP) rules under 19 C.F.R. part 111.[25]

The pattern: regulation is fragmented but often demand-creating — especially in shredding, where compliance mandates the service. Private buyers should verify licenses, permits, insurance, client indemnities, worker classification, and compliance history line-by-line and state-by-state.

8. Competitive dynamics and consolidation

By the numbers, this is one of the least-concentrated industries in the economy. The four largest firms account for just 14% of revenue (CR4), the top eight for 19.8%, the top twenty for 30.4%, and the top fifty for only 42.4%.[2] The Herfindahl-Hirschman Index (HHI — a standard concentration measure where higher means more concentrated) is 75.2,[2] roughly twenty times below the ~1,500 level U.S. antitrust agencies have historically used to flag a market as concentrated. In plain terms: extreme fragmentation, thousands of small operators, no dominant player overall.

But that headline should not be read as one unified competitive arena. Inventory counting, meter reading, traffic flagging, auctioneering, and contract diving have different customers, regulations, and economics; they compete on labor availability, coverage, scheduling reliability, data accuracy, insurance capacity, and relationships — not against each other.

The fragmentation is the investment opportunity, but consolidation happens within niches, not across the whole code. Disciplined consolidators have been assembling scale: PE-backed AWP Safety and RoadSafe have each completed strings of acquisitions to build national traffic-control platforms;[16] inventory/merchandising has reshuffled through the WIS–RGIS–Acosta chain (WIS bought RGIS's U.S./Canada business, then sold CROSSMARK and Product Connections to Acosta);[19][20][21] and shredding has been rolled into Iron Mountain and, via the Stericycle/WM deal, into a waste major.[9] The playbook is the same everywhere: local density plus route efficiency, a recognizable brand, national-account contracts, and a valuation re-rate as the platform grows. Barriers to entry are low at the single-operator level but rise with certification (NAID, DOT prequalification), national-account requirements, and route density.

9. Risks

• No pure public vehicle / misleading comparability. Public investors cannot cleanly own the industry; exposure comes diluted inside larger companies with their own drivers, and firms in adjacent NAICS codes may not be true peers.
• Labor-cost and driver-supply exposure. These are wage- and vehicle-intensive; labor inflation, turnover, absenteeism, fuel, and worker-classification disputes compress margins quickly.
• Customer concentration. Losing one national retail, utility, or logistics contract can materially hurt a small provider.
• Execution liability. Inaccurate counts, missed inspections, unsafe traffic control, or defective data can create claims.
• Cyclicality by niche. Traffic control depends on construction and public infrastructure budgets; inventory counting and auctioneering track retail and asset turnover — the pieces do not diversify each other because they respond to different cycles.
• Countercyclical-but-sensitive credit exposure. Repossession booms when borrowers default — good for that niche, but politically and legally sensitive (CFPB scrutiny, wrongful-repossession liability).
• Technology displacement. Automation threatens several sub-segments: smart utility meters (AMI — advanced metering infrastructure) erode manual meter reading; RFID (radio-frequency identification) and computer-vision counting reduce manual inventory labor; and the shift to digital records slowly shrinks the volume of paper to shred.
• Roll-up / leverage risk (private side). PE consolidators pay up and use debt; integration missteps, rising rates, or overpaying for add-ons can impair returns. Many large private operators publish no audited financials.
• Data-quality risk for analysts. Because the code is a residual bin dominated by nonemployers, official statistics undercount it and third-party sub-segment "market size" figures often use broader definitions than the code — making the industry hard to size precisely.

10. How to invest, and the outlook

Public-market routes. There is no direct play. Analyze each name by segment, not as a "sector" bet: focus on recurring contracts, direct-labor economics, customer concentration, cash conversion, reporting quality, and the share of revenue actually tied to the relevant service. The pragmatic themes are the shredding/records-and-waste theme via Iron Mountain (NYSE: IRM) or WM (NYSE: WM); the auction theme via RB Global (NYSE: RBA) and auction-adjacent Copart (NASDAQ: CPRT); and the retail field-execution theme via Advantage Solutions (NASDAQ: ADV) or the smaller SPAR Group (NASDAQ: SGRP). Pool-supply names Pool Corp (NASDAQ: POOL) and Leslie's (NASDAQ: LESL) offer read-through to pool-service demand but are themselves distribution/retail. Investors wanting the specific economics of 561990 will not find them cleanly on an exchange.

Private-market routes are where the industry genuinely trades. Direct ownership or acquisition of route-based service businesses — shredding, traffic control, pool service, inventory/merchandising, repossession forwarding — is the mainstream path, and PE-style buy-and-build is the dominant strategy. Value is created by buying small operators at modest multiples, densifying routes, winning national accounts, clearing certification/prequalification hurdles, and re-rating the platform. Favor businesses with repeatable contracts, strong local density, defensible data/compliance capabilities, low rework, diversified customers, and credible management succession; integration, labor retention, and leverage are the central risks.

Near-term outlook (forward-looking). Selectively constructive, not broad-based. Durable tailwinds: federal infrastructure and utility/broadband spending should keep work-zone traffic control busy; elevated auto-loan stress is likely to keep repossession volumes high; privacy-compliance mandates continue to underpin secure shredding; and inventory integrity and outsourced field execution stay in demand even as they digitize. The main structural headwind is automation — smart meters, automated counting, and digitization — which will gradually shrink the most manual, lowest-value niches. On balance, the more defensible opportunities are the contracted, compliance-driven, route-dense services (shredding, traffic control, inventory integrity) that a specialist can consolidate; the weakest are the purely manual, commoditized tasks technology is steadily replacing. Because official data undercounts the true, highly fragmented operator base, the consolidation runway in the strongest niches is likely longer than the headline $29.7 billion figure implies.

---

Sources

1. U.S. Census Bureau. "2022 NAICS Definition — 561990 All Other Support Services." 2022. https://www.census.gov/naics/?input=561990&year=2022&details=561990
2. U.S. Census Bureau. "2022 Economic Census — Concentration by Largest Firms, NAICS 561990" (receipts $29.68B; 10,554 firms; CR4 14%, CR8 19.8%, CR20 30.4%, CR50 42.4%; HHI 75.2). 2022. https://api.census.gov/data/2022/ecnsize.html
3. U.S. Census Bureau. "County Business Patterns, NAICS 561990" (12,567 establishments; 173,815 employees; $9.89B annual payroll; $2.34B Q1 payroll). 2023. https://www.census.gov/programs-surveys/cbp.html
4. U.S. Small Business Administration. "Table of Small Business Size Standards" (NAICS 561990: $16.5M average annual receipts). 2023. https://www.sba.gov/document/support-table-size-standards
5. SICCODE. "NAICS Code 561990 — All Other Support Services" (≈31,097 active companies — third-party directory count illustrating nonemployer undercount). 2025. https://siccode.com/naics-code/561990/support-services
6. PoolDial. "Pool Industry Statistics 2026 / How Many Pool Service Companies in the US? 125,000+" (pool-service market ~$8.6B; ~125,000 businesses; Pool Corp / Leslie's as distributors). 2026. https://pooldial.com/resources/articles/business/pool-industry-statistics-2026
7. IntelMarketResearch. "Secure Document Shredding Service Market Outlook 2026-2032" (U.S. shredding sub-market ~$3B in 2024; third-party market research). 2026. https://www.intelmarketresearch.com/secure-document-shredding-service-market-25929
8. Macrotrends. "Iron Mountain (IRM) Revenue 2012-2026" (revenue ~$6.15B, 2024). 2025. https://www.macrotrends.net/stocks/charts/IRM/iron-mountain/revenue
9. WM (Waste Management). "WM Completes Acquisition of Stericycle" ($7.2B enterprise value; closed Nov 4, 2024; Shred-it secure shredding). 2024. https://investors.wm.com/news-releases/news-release-details/wm-completes-acquisition-stericycle
10. TipRanks. "RB Global's 2024 Earnings Reflect Strategic Growth" (revenue $4.28B, 2024; Ritchie Bros. + IAA). 2025. https://www.tipranks.com/news/company-announcements/rb-globals-2024-earnings-reflect-strategic-growth
11. SICCODE. "Copart Inc — NAICS 441228 (Motorcycle, ATV, and All Other Motor Vehicle Dealers)." 2025. https://siccode.com/business/copart-inc
12. U.S. Securities and Exchange Commission. "Advantage Solutions Inc. Form 10-K" (retail merchandising, in-store sampling, demonstrations, shopper marketing). 2026. https://www.sec.gov/Archives/edgar/data/1776661/000119312526088543/adv-20251231.htm
13. U.S. Securities and Exchange Commission. "SPAR Group, Inc. Form 10-K" (retail merchandising and store-execution services). 2026. https://www.sec.gov/Archives/edgar/data/1004989/000143774926010508/sgrp20251231_10k.htm
14. U.S. Securities and Exchange Commission. "Expeditors International of Washington, Inc. Form 10-K for FY2024" (customs brokerage and other services ~36% of 2024 revenue). 2025. https://www.sec.gov/Archives/edgar/data/746515/000095017025024750/expd-20241231.htm
15. U.S. Census Bureau. "2022 Economic Census — Transportation and Warehousing" (customs brokerage classified under freight transportation arrangement, NAICS 488510). 2022. https://bhs.econ.census.gov/ombpdfs2022/export/2022_TW-48800_su.pdf
16. PR Newswire / PE Hub. "AWP Safety, Backed by Kohlberg & Co., Announces Strategic Acquisition; RoadSafe backed by Investcorp and Trilantic." 2023-2024. https://www.prnewswire.com/news-releases/awp-safety-backed-by-kohlberg--co-announces-strategic-acquisition-of-rhv-capitals-traffic-control-group-301891696.html
17. Resolvion. "22 Repo Industry Statistics, Trends & Analysis" (≈1.9M vehicles repossessed in 2024; forwarding-company model). 2025. https://resolvion.com/22-repo-industry-statistics-trends-analysis/
18. WIS International. "About Us / Reliable Inventory Management Solutions" (inventory counting, store setup, remodels, space mapping; technology-enabled counting). 2026. https://wisintl.com/about-us/
19. RGIS. "Embarking on a New Era of Growth and Innovation" (WIS acquired RGIS's former U.S. and Canadian operations). 2023. https://www.rgis.co.uk/news/embarking-on-a-new-era-of-growth-and-innovation/
20. WIS International. "WIS International Divests CROSSMARK & Product Connections." 2024. https://wisintl.com/news-acosta/
21. Acosta Group. "Acosta Group Completes Acquisition of Crossmark and Product Connections." 2024. https://www.acosta.group/acosta-group-completes-acquisition-of-crossmark-and-product-connections/
22. A.N. Deringer. "Customs Broker, Freight Forwarding & Trade Compliance Services" (privately held customs broker, NAICS 488510, adjacent to 561990). 2026. https://www.anderinger.com/
23. Olameter. "Meter Reading / Utility Services" (contract meter-reading provider serving 350+ North American utility clients). 2025. https://www.olameter.com/service/meter-services/meter-reading
24. CT Acquisitions. "Traffic Control Business Valuation 2026: Multiples & DOT Prequal Premium" (work-zone control ~3-8% of project value; DOT prequalification premium). 2026. https://ctacquisitions.com/guides/traffic-control-business-valuation/
25. U.S. Customs and Border Protection. "Customs Brokers" (broker licensing under 19 C.F.R. part 111). 2025. https://www.cbp.gov/trade/programs-administration/customs-brokers
26. U.S. Federal Trade Commission. "Advertising and Marketing Basics / Endorsement Guides (updated 2023)." 2026. https://www.ftc.gov/business-guidance/advertising-marketing
27. U.S. Department of Labor. "Misclassification of Employees as Independent Contractors Under the Fair Labor Standards Act." 2026. https://www.dol.gov/agencies/whd/flsa/misclassification