Professional Organizations (U.S.) — NAICS 813920

An industry primer for public-market and private investors

1. Overview

"Professional organizations" are the membership bodies that represent a profession and its practitioners — the American Medical Association (AMA), the American Bar Association (ABA), the Institute of Electrical and Electronics Engineers (IEEE), the Project Management Institute (PMI), and thousands of smaller societies. Under the North American Industry Classification System (NAICS) — the statistical scheme U.S. agencies use to classify businesses — this is code 813920: establishments "primarily engaged in promoting the professional interests of their members and the profession as a whole." Typical activities are running certifications and standards, publishing journals, holding conferences, offering continuing education, and advocating on the profession's behalf. [1]

What makes this sector unusual for an investor is that you generally cannot buy the organizations themselves. Almost every entity in NAICS 813920 is a member-governed, tax-exempt nonprofit — there is no stock in the AMA or IEEE, and net earnings cannot be paid to private shareholders. [11] What matters is that these bodies sit on top of durable, cash-generating assets — copyrighted code sets, professional credentials, peer-reviewed journals, mandatory continuing-education requirements — and they pay a large ecosystem of for-profit vendors (testing firms, publishers, event operators, software providers) to deliver them. The investable exposure lives in that surrounding layer, not in the associations.

• Public-market route: diversified professional-information, publishing, testing, and event companies that monetize the same professions — no pure-play "professional organization" stock exists.
• Private route: private equity and employee-owned firms hold much of the certification/testing, association-management, and event-technology infrastructure; the associations themselves are member-governed and are not for sale.

2. What it is and how it's structured

NAICS 813920 is activity-based, not ownership-based — the code describes what an establishment does, so an entity could in principle be nonprofit, member-owned, or commercial. In practice the population is overwhelmingly member-governed nonprofits. [1]

In scope (813920): national, state, and local associations and "learned societies" for a licensed or credentialed profession. Census illustrative examples include bar associations, medical and dental associations, engineers' and scientists' associations, nurses' and pharmacists' associations, peer-review boards, and professional-standards review boards. The common thread is advancing a profession — as distinct from a business or industry. [1]

What it excludes — and the adjacent codes:

• 813910 Business Associations — groups promoting the business interests of members (trade associations, chambers of commerce, manufacturers' associations). A medical association is 813920; a hospital-industry association is 813910. [1]
• 541820 Public Relations Agencies — organizations whose primary activity is lobbying public officials. An association may still lobby as part of a broader mission; the exclusion bites only when lobbying is the establishment's main classified activity. [1]
• 813410 Civic and Social Organizations, and 813930 Labor Unions, 813940 Political Organizations, 813990 Other Similar Organizations — the rest of the 8139 "membership organizations" family. [1]
• Commercial work associations often do, but that is coded elsewhere when done for profit: professional and management training (611430), convention and trade-show organizing (561920), and journal/book publishing (511/519).

Ownership mix: predominantly 501(c)(6) tax-exempt "business leagues" (the Internal Revenue Code section covering professional associations), frequently paired with an affiliated 501(c)(3) charitable/educational foundation for research and scholarships. [11] These are member-governed nonprofits with boards and volunteer leaders, not investor-owned firms — there are no shareholders, and surpluses build reserves rather than pay dividends. A handful of giants coexist with thousands of small state and local chapters. The federal statistics do not provide a legal-form or ownership breakdown, so a precise nonprofit-versus-commercial split cannot be stated.

3. How big it is

Federal business statistics for NAICS 813920 (U.S. Census Bureau and SBA):

A few reading notes. The years differ — employment and payroll are 2023, while receipts and firm concentration are 2022. "Receipts" is gross revenue, not profit or free cash flow. The SBA's $23.5 million figure is a federal-contracting threshold, not a valuation measure.

The undercount caveat — important here. The ~$22.7 billion receipts figure and the ~6,500-establishment count capture only entities with paid employees, measured the way Census counts business receipts. They understate the sector's real footprint for three reasons:

1. Thousands of small societies run on volunteers. Countless state, local, and specialty professional societies have no paid staff and therefore no payroll, so they largely fall out of County Business Patterns (CBP), which covers employer establishments and excludes most nonemployer and government bodies. [2]
2. Nonprofit revenue is measured differently. These bodies raise money as dues, royalties, and grants rather than "sales receipts," and some of their largest streams — scientific publishing, abstracting databases, credentialing — are partly captured under publishing or education codes, not 813920.
3. Counting all trade and professional nonprofits together gives a much larger picture. One nonprofit database counts roughly 45,600 combined trade and professional associations in the U.S., employing ~133,000 people, with $45+ billion of annual revenue and $71 billion of assets — a superset that also includes 813910 business associations, but a signal of the true scale. [15]

The supplied federal file contains no nonemployer estimate, so no adjustment should be invented. Net: 813920 is a modestly sized but influential slice of the economy, fragmented into many tiny bodies plus a few very large ones.

4. The investable universe

There are effectively no publicly traded "professional organizations." The entities that are NAICS 813920 are all member-governed nonprofits with no stock. Their approximate scale (latest available revenue) shows why they matter even though you can't buy them:

Where investors actually get exposure — the for-profit ecosystem that serves these professions. These are diversified global companies; association-related work is one segment among several, not a pure-play bet. Tickers are given because these are the practical public entry points:

Over half of all "professional information" revenue flows to RELX, Thomson Reuters, and Wolters Kluwer combined — the three publish or license the journals, standards, and legal/medical databases that associations either use or compete with. [14]

Private and other owners. The certification-testing layer is largely private-equity- or corporate-owned: Prometric (delivers tens of millions of exam hours a year) and PSI Services (serves 130+ certifying organizations) sit alongside Pearson's Pearson VUE. [13] The association-management company (AMC) layer — firms that run associations' back offices under contract — includes employee-owned Smithbucklin (organized as an ESOP) and MCI USA. [20] Event and member technology has drawn heavy private-equity interest: Cvent (event-management software) was taken private by Blackstone-managed funds, with a minority stake from the Abu Dhabi Investment Authority and Vista Equity Partners [21]; member-management software (iMIS, MemberClicks, Community Brands) is mostly private/PE-held. The associations themselves cannot be acquired.

5. How the money works

A professional organization's economics look nothing like an ordinary company's. The model is membership plus non-dues revenue, and over two decades the balance has shifted decisively toward the latter.

• Membership dues. Members × an annual rate that runs from tens to a few hundred dollars (AMA ~$400; ADA ~$600; ABA ~$75–$450). At the big societies dues are now a minority of revenue and shrinking as a share — AMA dues fell from ~15% of revenue in 2011 to under 8% by 2023, and IEEE membership is under 10% of revenue. [3][5][10] Key operating metrics are member penetration (share of eligible professionals who join), renewal/retention, and dues price sensitivity.

• Non-dues revenue — the real engine. Durable, recurring income tied to an asset the association owns:

• Intellectual-property royalties. The archetype is the AMA's Current Procedural Terminology (CPT) code set — the copyrighted list of medical procedure codes that essentially every U.S. insurer, hospital, and physician must license to bill for care. CPT royalties grew from ~$66 million in 2011 to ~$285 million in 2023, from a quarter to more than half of AMA revenue: a toll booth on an entire profession. [3]
• Certification and credentialing. Exam fees plus recurring renewal/maintenance fees for credentials like the PMP (project management), CPA (accounting), or SHRM-CP (human resources). Where a credential is required or preferred by employers, this is annuity-like income. [6][8]
• Continuing education. Continuing medical/professional education (CME/CPE/CE) that professionals must complete to keep a license — a recurring, regulation-driven stream.
• Publishing. Journal subscriptions, advertising, reprints, standards, and databases — the dominant source at ACS and IEEE. [4][5]
• Conferences and trade shows. Registration fees, sponsorships, and exhibit-space sales.

• Affinity programs and grants. Commissions from insurance, credit cards, and member benefits, plus research grants and contributions. [3]

• The cost base is people- and content-intensive: professional staff, editorial and standards work, member acquisition, technology, venues and event production, marketing, insurance, and compliance. AMCs earn their keep by spreading shared finance, technology, and event costs across many client associations. [20]

• What a "good" one looks like. With no shareholders, success is measured as recurring non-dues revenue per member, operating surplus routed to reserves/net assets (PMI holds ~$600 million of net assets), and investment income earned on those reserves. [6] The strongest bodies own a standard or credential the profession cannot work without, giving them monopoly-like pricing power inside a niche.

• Tax angle. As 501(c)(6) nonprofits they pay no tax on mission income, but commercial activities — journal advertising, services sold to non-members, non-member training — are taxed as unrelated business income; an organization with $1,000+ of gross unrelated-business income generally files IRS Form 990-T. [12]

6. What drives demand

• Size and growth of the underlying profession. More physicians, engineers, accountants, and project managers means more potential members, exam-takers, and readers. Demand tracks white-collar professional employment.
• Licensure and mandatory continuing education. The strongest structural tailwind: when a state requires a license, and the license requires periodic continuing education, associations gain a captive, recurring market for CE and certification.
• Employer demand for credentials. When employers require or reward a credential (PMP, CPA, SHRM-CP), individuals pay to earn and keep it regardless of how they value "membership."
• Regulatory reliance on association-owned standards. When government payers and regulators build a private code set or standard into how the system runs (CPT in medical billing), demand becomes non-discretionary.
• Digital delivery expands geographic reach and lowers distribution cost, widening the addressable pool.
• The value-of-membership question — working against demand. Free professional networks (LinkedIn, online communities) and employer-provided training erode the traditional reason to pay dues. Artificial intelligence (AI) cuts both ways: it can improve member service, content discovery, and event matchmaking, but it also makes generic newsletters, basic education, and broad networking easier to substitute. This is why dues keep falling as a share of revenue.

7. Regulation

• Tax exemption and disclosure. Professional organizations operate under IRC 501(c)(6) (often with an affiliated 501(c)(3) arm), must promote a common professional interest broadly rather than individual members' private businesses, and file public Form 990 returns — which makes their finances unusually transparent. [11] Regularly conducted business unrelated to the exempt purpose is taxable; $1,000+ of gross unrelated-business income triggers a Form 990-T filing. [12]
• Lobbying rules. Associations may lobby when related to their exempt purpose, but dues used for lobbying can trigger member notices or a proxy tax, and crossing into primarily lobbying reclassifies that work (to 541820). [11]
• Antitrust — a recurring exposure. Because associations bring competitors together to write ethics codes, set standards, and run certification, the Federal Trade Commission (FTC) treats price coordination, boycotts, exclusionary standards, and advertising restrictions as liability risks. [16] The Supreme Court struck down the engineers' ban on competitive bidding in National Society of Professional Engineers v. United States (1978), and litigated dental-association limits on truthful advertising in California Dental Association v. FTC (1999). Standard-setting and credentialing must be run carefully to stay on the right side of the Sherman Act. [16]
• Open-access mandates. Requirements from research funders (e.g., Plan S, launched 2018, and U.S. federal public-access rules) pressure the subscription-journal revenue that funds science and engineering societies, forcing a shift toward author-paid open access. [17]
• State and operational law. State nonprofit and charitable-solicitation rules, privacy/data-protection requirements, credentialing standards, employment law, and event contracts all apply.

8. Competitive dynamics and consolidation

The federal concentration data confirm an unusually fragmented industry: a Herfindahl-Hirschman Index (HHI, the standard concentration measure) of just 51.6, with the top 4 firms holding 10.6% of receipts, the top 8 15.8%, the top 20 24.4%, and the top 50 35.5%. [2] For reference, an HHI above 2,500 is "highly concentrated," so 813920 is about as fragmented as industries get.

But the headline number misleads at ground level. Within any single profession, one national body is usually a near-monopoly — there is one AMA, one AICPA, one PMI — surrounded by specialty societies and state/local chapters. Fragmentation across the whole industry coexists with dominance inside each niche. Competition turns on member trust, professional reputation, credential value, exclusive content and standards, and flagship events rather than price.

Consolidation is more likely in the adjacent commercial layers than among the associations themselves:

• Society mergers and federations — e.g., the AICPA's combination with the U.K.'s Chartered Institute of Management Accountants (CIMA) to form the Association of International Certified Professional Accountants. [7]
• Scale in publishing and certification favors the largest societies and pushes small ones to merge or affiliate; for-profit competition comes from technology-vendor certifications, commercial CE providers, and commercial publishers (RELX, Wolters Kluwer, Wiley). [14][22]
• Private-equity roll-ups in the vendor layer — Blackstone's take-private of Cvent shows the appetite for event/association technology [21]; in the events business, Apollo-affiliated funds completed a take-private of B2B event operator Emerald Holding in 2026 [18]. (Separately, and confusingly, Wiley acquired the scholarly publisher Emerald Publishing in 2026 — a different company. [22])

The likely winning model is a bundled platform combining membership, content, education, credentialing, software, and events.

9. Risks

• Structural decline of the dues model. Younger professionals increasingly see less value in paid membership; dues have fallen as a share of revenue across the sector and could keep falling. [3][5]
• Over-reliance on a single asset. Bodies whose economics hinge on one royalty or credential (CPT for the AMA) carry concentrated copyright, political, and antitrust risk against that stream. [3]
• Open-access and content substitution. Subscription-journal economics erode as funders mandate free access and as AI reduces the scarcity of professional content. [17]
• Certification disruption. AI and alternative micro-credentials could weaken the value of some certifications and CE content.
• Events exposure. Cancellations, attendance weakness, venue inflation, and sponsor/exhibitor concentration hit the event line directly.
• Antitrust and regulatory action against standard-setting, ethics codes, and credentialing; plus tax-exemption disputes and lobbying-compliance errors. [16]
• Trust, governance, and cyber risk. A credentialing, research-integrity, or governance failure damages the core asset (trust); member, credential, and event data create privacy and cybersecurity exposure.
• Reputational / "capture" risk. Associations are periodically criticized for serving their own revenue or a narrow member interest, inviting political pushback.
• Investment-portfolio risk. Large reserves mean results are partly exposed to financial markets.
• Proxy dilution (for public-company exposure). In the listed vendors, company-wide leverage, acquisitions, foreign-exchange, and unrelated business lines can swamp the association-related segment.

10. How to invest, and the outlook

There is no direct way to invest in professional organizations — they are nonprofits with no equity. Direct participation is a grant, program-related investment, loan, or mission-aligned contribution, not ordinary ownership. Investors gain exposure indirectly:

• Public markets. Buy the professional-information, publishing, testing, and event incumbents that monetize the same professions: RELX, Thomson Reuters, Wolters Kluwer (publishing/data/software), Pearson (certification testing via Pearson VUE), Informa (professional events), and John Wiley & Sons (society publishing). [13][14][22] Because these are diversified, analyze each company's actual exposure — recurring revenue, customer/member retention, revenue per member, event rebooking, exhibitor/sponsor concentration, credential renewals, subscription growth, content licensing, and acquisition integration — rather than treating the whole company as a proxy.
• Private markets. Private equity and employee ownership are the main routes into the association-services infrastructure: certification and licensure testing (Prometric, PSI), continuing-education content, association-management companies (Smithbucklin, MCI USA), member-management software, and event technology (Cvent). [13][20][21] Diligence should focus on member/client renewal history, revenue concentration by association/event/sponsor, recurring-versus-transactional mix, credential and standards defensibility, data ownership, event-cancellation provisions and working capital, and governance/tax/antitrust controls. The associations themselves cannot be acquired.

Near-term drivers to watch:

• Whether licensure and mandatory continuing-education requirements hold — the regulatory backbone of certification and CE revenue.
• The durability of association-owned standards under legal and political pressure, with the AMA's CPT royalty stream the bellwether.
• The pace of the open-access transition and its hit to society-journal economics. [17]
• How associations replace shrinking dues with data, certification, and digital products — and whether AI erodes or reinforces the value of their credentials and content.

Outlook. Expect a durable but uneven, barbell-shaped industry: large societies that own an indispensable standard, credential, or database should retain strong pricing power, while smaller dues-dependent bodies face substitution and consolidation. For investors, the money is in the toll-collecting infrastructure — testing, publishing, data, software, and events — not in the member organizations at the center of it. This is a forward-looking judgment; the supplied federal file contains no industry growth forecast, margin series, or member-retention data.

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Sources

1. U.S. Census Bureau, "2022 NAICS Definition — 813920 Professional Organizations." https://www.census.gov/naics/?details=813920&input=813920&year=2022
2. Our ingested federal ground-truth for NAICS 813920: U.S. Census Bureau, County Business Patterns (2023); 2022 Economic Census — Concentration of Largest Firms (EC2200SIZECONCEN); U.S. Small Business Administration, Table of Size Standards (2023). https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN and https://www.sba.gov/document/support-table-size-standards
3. STAT News, "The AMA, lobbying, CPT billing codes and CME" (2025); Paddock Post, "How the AMA Spends Revenue" (2024–2025); InfluenceWatch, "American Medical Association." https://www.statnews.com/2025/06/13/american-medical-association-lobbying-cpt-billing-codes-cme/
4. American Chemical Society, "Financial Overview" and audited financial statements (2024). https://www.acs.org/about/aboutacs/financial/overview.html
5. IEEE, "Financials" (ieee.org); Paddock Post, "How IEEE Spends Revenue" (2023). https://www.ieee.org/about/financials
6. Project Management Institute, "2024 Annual Report"; ProPublica Nonprofit Explorer (EIN 23-1887442). https://www.pmi.org/about/annual-reports
7. American Institute of Certified Public Accountants (AICPA) / Association of International Certified Professional Accountants — corporate profile and AICPA–CIMA combination. https://en.wikipedia.org/wiki/American_Institute_of_Certified_Public_Accountants
8. Society for Human Resource Management (SHRM) — corporate profile and certifications. https://en.wikipedia.org/wiki/Society_for_Human_Resource_Management
9. American Dental Association, "ADA House of Delegates approves 2023 budget" and dues notices (2022–2023). https://adanews.ada.org/ada-news/2022/october/ada-house-of-delegates-approves-2023-budget
10. American Bar Association, "Dues & Eligibility"; Paddock Post, "How Membership Dues are Spent at the ABA" (2019). https://www.americanbar.org/membership/dues_eligibility/
11. Internal Revenue Service, "Business Leagues" — Requirements for Exemption, Section 501(c)(6). https://www.irs.gov/charities-non-profits/other-non-profits/business-leagues
12. Internal Revenue Service, "Unrelated Business Income Tax" and Form 990-T guidance. https://www.irs.gov/charities-non-profits/unrelated-business-income-tax
13. Pearson VUE, "Test Development & Delivery Solutions"; Prometric; PSI Services, "Professional certifications testing" (2024–2025). https://www.pearsonvue.com/us/en/test-owners.html
14. RELX plc Annual Report (2025); Thomson Reuters Annual Report (2025); Wolters Kluwer corporate profile; Rupak Ghose, analysis of RELX / Thomson Reuters / Wolters Kluwer professional-information revenue. https://www.relx.com/investors and https://investors.thomsonreuters.com/
15. Cause IQ, "Trade / professional associations and chambers of commerce" directory (combined 813910 + 813920 nonprofits). https://www.causeiq.com/directory/trade-professional-associations-list/
16. U.S. Federal Trade Commission, "Dealings with Competitors" / "Other Agreements Among Competitors"; National Society of Professional Engineers v. United States, 435 U.S. 679 (1978); California Dental Association v. FTC, 526 U.S. 756 (1999). https://www.ftc.gov/advice-guidance/competition-guidance/guide-antitrust-laws/dealings-competitors and https://supreme.justia.com/cases/federal/us/435/679/
17. Science (AAAS), "A mixed review for Plan S's drive to make papers open access"; Nature, coverage of Plan S and open-access mandates (2019–2021). https://www.science.org/content/article/mixed-review-plan-s-s-drive-make-papers-open-access
18. U.S. Securities and Exchange Commission, Emerald Holding Form 8-K — completion of Apollo take-private (2026). https://www.sec.gov/Archives/edgar/data/1579214/000119312526303283/d101061d8k.htm
19. Informa plc, Annual Report (2025) — B2B events, exhibitions, and academic markets. https://www.informa.com/investors/
20. Smithbucklin, "Company Facts" (employee-owned/ESOP association-management company); MCI USA, "Association Management Services." https://smithbucklin.com/About-Us/company-facts and https://www.wearemci.com/en-us/associations/association-management
21. Cvent, "Blackstone Completes Acquisition of Cvent" (with Abu Dhabi Investment Authority and Vista Equity Partners). https://www.cvent.com/en/press-release/blackstone-completes-acquisition-cvent
22. John Wiley & Sons, 2025 Annual Report / Form 10-K (society publishing platforms and services); Wiley newsroom, "Wiley Acquires Emerald Publishing" (2026). https://www.sec.gov/Archives/edgar/data/107140/000010714025000147/wly-20250430x10kx2025.pdf and https://newsroom.wiley.com/press-releases/press-release-details/2026/Wiley-Acquires-Emerald-Expanding-Research-Scale-and-Deepening-Proprietary-Content-Across-the-AI-Driven-Knowledge-Economy/default.aspx