# List of professional services firms in Pennsylvania

Tamtam tracks 245 professional services firms headquartered in Pennsylvania. This list ranks the 50 largest by number of employees on LinkedIn, led by EPAM Systems, Aramark and Unisys. Their median headcount is 1,952. Half of them were founded in 1970 or later. The most common headquarters are Philadelphia (17), Pittsburgh (5) and Blue Bell (3).

This selection of large professional services firms in Pennsylvania includes global providers of IT services and consulting like EPAM Systems, which specializes in product development and engineering, and Unisys, offering digital workplace and cloud solutions. It also features major hospitality service providers such as Aramark, delivering food and facilities management, and HHM Hotels, managing a portfolio of 240 hotels. Legal services are represented by firms like Morgan, Lewis & Bockius LLP and K&L Gates, providing corporate, regulatory, and litigation counsel.

The companies listed demonstrate a concentration of headquarters in the Philadelphia area, with many also located in Pittsburgh and Blue Bell. The industries represented are diverse, ranging from IT and legal services to hospitality, engineering, and construction, indicating a varied professional services landscape within the state.

🇺🇸 Pennsylvania · 50 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [EPAM Systems](https://www.tamtam.ai/c/epam-systems) (epam.com)<br>Global digital transformation services provider specializing in product development and engineering, creating better enterprise, education, and health platforms worldwide | IT Services and IT Consulting | 🇺🇸 Newtown | 66,049 | 1993 |
| 2 | [Aramark](https://www.tamtam.ai/c/aramark) (aramark.com)<br>Global hospitality service provider delivering food and facilities management to educational institutions, healthcare providers, sports teams, and municipalities across sixteen countries worldwide. | Hospitality | 🇺🇸 Philadelphia | 56,723 | 1939 |
| 3 | [Unisys](https://www.tamtam.ai/c/unisys) (unisys.com)<br>A global technology solutions company offering digital workplace, cloud, applications & infrastructure, enterprise computing, and business process solutions to empower organizations | IT Services and IT Consulting | 🇺🇸 Blue Bell | 23,358 |  |
| 4 | [Morgan, Lewis & Bockius LLP](https://www.tamtam.ai/c/morgan-lewis-and-bockius-llp) (morganlewis.com)<br>Legal professionals providing corporate, transactional, litigation, and regulatory services to diverse industries worldwide, supporting clients' immediate and long-term goals. | Law Practice | 🇺🇸 Philadelphia | 5,068 | 1873 |
| 5 | [K&L Gates](https://www.tamtam.ai/c/k-and-l-gates) (klgates.com)<br>Global law firm providing expert legal counsel across corporate, regulatory, and litigation matters for diverse industries and public sector clients. | Law Practice | 🇺🇸 Pittsburgh | 4,682 |  |
| 6 | [Michael Baker International](https://www.tamtam.ai/c/michael-baker-international) (mbakerintl.com)<br>Comprehensive engineering, consulting, and technology services for infrastructure projects including design, planning, environmental, and program management across multiple sectors. | Civil Engineering | 🇺🇸 Pittsburgh | 4,466 | 1940 |
| 7 | [Korn Ferry Hay Group](https://www.tamtam.ai/c/korn-ferry-hay-group) (kornferry.com)<br>Global organizational consulting firm helping companies design their structure, roles, compensation, and hire talent to execute strategy in over 50 countries | Management Consulting | 🇺🇸 Philadelphia | 4,258 | 1943 |
| 8 | [Day & Zimmermann](https://www.tamtam.ai/c/day-and-zimmermann) (dayzim.com)<br>Global company specializing in construction, engineering, operations, maintenance, staffing, and security services with extensive experience and worldwide presence. | Construction | 🇺🇸 Philadelphia | 4,211 | 1901 |
| 9 | [IPS-Integrated Project Services](https://www.tamtam.ai/c/ips-integrated-project-services) (ipsdb.com)<br>Technical consulting, architecture, engineering, procurement, and construction management for complex facilities through commissioning, validation, and compliance services to accelerate operational readiness and market speed. | Business Consulting and Services | 🇺🇸 Blue Bell | 3,932 | 1989 |
| 10 | [CAI](https://www.tamtam.ai/c/cai-allentown) (cai.io)<br>Global services firm combining talent and technology to deliver customized solutions across public and commercial sectors, emphasizing neurodiversity inclusion. | Professional Services | 🇺🇸 Allentown | 2,773 | 1981 |
| 11 | [HHM Hotels](https://www.tamtam.ai/c/hhm-hotels) (hhmhotels.com)<br>A leading hotel operator managing a portfolio of 240 hotels in the United States and Canada, known for delivering consistent results and focusing on people, processes, and technology | Hospitality | 🇺🇸 Philadelphia | 2,716 |  |
| 12 | [The Judge Group](https://www.tamtam.ai/c/the-judge-group) (judge.com)<br>Provides international business technology consulting, talent solutions, and corporate learning services across various industries including healthcare and finance through thirty global office locations. | Business Consulting and Services | 🇺🇸 Wayne | 2,642 | 1970 |
| 13 | [DSA](https://www.tamtam.ai/c/dsa) (dsainc.com)<br>A leading IT and consulting firm providing mission-driven solutions to Defense, Federal Government, Universities, and private industry partners across the country | IT System Operations and Maintenance | 🇺🇸 Trevose | 2,578 | 1963 |
| 14 | [SSi People](https://www.tamtam.ai/c/ssi-people) (ssipeople.com)<br>An experienced staffing organization based in PA, connecting Fortune 1000 companies with skilled professionals across various industries in the US | Staffing and Recruiting | 🇺🇸 Cranberry Township | 2,443 | 1998 |
| 15 | [Inizio Engage](https://www.tamtam.ai/c/inizio-engage) (inizioengage.com)<br>A global healthcare engagement partner offering strategic, commercial, and creative solutions through consultation, technology, and activation expertise to inspire lasting change | Hospitals and Health Care | 🇺🇸 Yardley | 2,352 |  |
| 16 | [Language Services Associates](https://www.tamtam.ai/c/language-services-associates) (lsa.inc)<br>Global language services provider, offering solutions in interpretation, translation, localization, and assessments to help individuals and companies thrive internationally | Translation and Localization | 🇺🇸 Horsham | 2,287 | 1991 |
| 17 | [Fox Rothschild](https://www.tamtam.ai/c/fox-rothschild) (foxrothschild.com)<br>A national law firm with 1,000 attorneys providing personalized legal solutions, prioritizing innovation, and building lasting relationships based on trust and success | Law Practice | 🇺🇸 Philadelphia | 2,241 | 1907 |
| 18 | [Civil & Environmental Consultants, Inc.](https://www.tamtam.ai/c/civil-and-environmental-consultants-inc) (cecinc.com)<br>A comprehensive consulting firm offering innovative solutions in various areas such as air quality, civil engineering, environmental sciences, and waste management for a range of industries | Civil Engineering | 🇺🇸 Moon Township | 2,226 | 1989 |
| 19 | [Cozen O'Connor](https://www.tamtam.ai/c/cozen-o-connor) (linktr.ee)<br>A top-ranked law firm with 825+ attorneys in 31 cities globally, specializing in litigation, business law, and government relations for diverse clients | Law Practice | 🇺🇸 Philadelphia | 2,150 | 1970 |
| 20 | [Dechert LLP](https://www.tamtam.ai/c/dechert-llp) (dechert.com)<br>Provides legal advice on litigation, transactions, and regulatory matters across financial services, private capital, real estate, life sciences, and technology sectors. | Law Practice | 🇺🇸 Philadelphia | 2,145 | 1875 |
| 21 | [Core States Group](https://www.tamtam.ai/c/core-states-group) (core-states.com)<br>A collaborative team offering architecture, interior design, engineering, program management, and construction solutions nationwide, focused on facilitating a remarkable customer experience | Engineering Services | 🇺🇸 West Chester | 2,134 | 1999 |
| 22 | [DDI \| Development Dimensions International](https://www.tamtam.ai/c/ddi-development-dimensions-international) (ddiworld.com)<br>Global leadership consulting firm assisting organizations with hiring, promotion, and development of exceptional leaders from first-time managers to senior C-suite executive levels. | Human Resources Services | 🇺🇸 Bridgeville | 2,120 | 1970 |
| 23 | [Yoh, A Day & Zimmermann Company](https://www.tamtam.ai/c/yoh-a-day-and-zimmermann-company) (yoh.com)<br>Yoh specializes in fulfilling talent demands across various industries, offering expertise in IT, Fintech, Cybersecurity, Healthcare, and more with a focus on thought leadership and local support | Staffing and Recruiting | 🇺🇸 Philadelphia | 2,059 | 1940 |
| 24 | [Ballard Spahr LLP](https://www.tamtam.ai/c/ballard-spahr-llp) (ballardspahr.com)<br>Provides litigation, transactional, and regulatory legal services to diverse clients, leveraging technology for efficiency and strategic counsel. | Law Practice | 🇺🇸 Philadelphia | 1,990 | 1885 |
| 25 | [Duane Morris LLP](https://www.tamtam.ai/c/duane-morris-llp) (duanemorris.com)<br>Provides innovative legal solutions globally with over 900 attorneys, emphasizing partnership, inclusiveness, and consensus in addressing client challenges. | Law Practice | 🇺🇸 Philadelphia | 1,952 | 1904 |
| 26 | [CEI](https://www.tamtam.ai/c/cei) (cei.ai)<br>Providing AI-enabled consulting, development, and management services to modernize IT systems and drive business growth and operational excellence. | IT Services and IT Consulting | 🇺🇸 Pittsburgh | 1,816 | 1992 |
| 27 | [Nursing Care Services, Inc.](https://www.tamtam.ai/c/nursing-care-services-inc) (nursingcareservices.com)<br>A medical staffing and home care firm founded in 1992, providing qualified medical and home care staff to various facilities and private residences in Pennsylvania | Staffing and Recruiting | 🇺🇸 Lansdale | 1,766 |  |
| 28 | [Gannett Fleming](https://www.tamtam.ai/c/gannett-fleming) (gftinc.com)<br>A privately held AEC firm providing comprehensive infrastructure solutions in various markets including transportation, water resources, and energy Founded in 1915 | Civil Engineering | 🇺🇸 Mechanicsburg | 1,756 |  |
| 29 | [Blank Rome LLP](https://www.tamtam.ai/c/blank-rome-llp) (blankrome.com)<br>An Am Law 100 firm with 15 offices and 700 attorneys providing legal services worldwide, known for industry expertise and commitment to pro bono work | Law Practice | 🇺🇸 Philadelphia | 1,749 | 1946 |
| 30 | [ClinChoice](https://www.tamtam.ai/c/clinchoice) (clinchoice.com)<br>A global clinical CRO offering high-quality, efficient solutions to clients worldwide in biostatistics, clinical operations, data management, regulatory affairs, and more | Pharmaceutical Manufacturing | 🇺🇸 Horsham | 1,624 | 1995 |
| 31 | [FCA](https://www.tamtam.ai/c/fca) (fcarchitects.com)<br>Full-service architectural and design firm creating resonant spaces for clients, incorporating collaboration, enhancing lives, and promoting environmental responsibility through defined, rigorous processes | Architecture and Planning | 🇺🇸 Philadelphia | 1,604 | 1954 |
| 32 | [CMI Media Group](https://www.tamtam.ai/c/cmi-media-group) (cmimediagroup.com)<br>A full-service media agency specializing in health, wellness, and pharmaceutical marketing Offering audience strategy, data analytics, buying, and direct response services | Advertising Services | 🇺🇸 Philadelphia | 1,599 | 1989 |
| 33 | [PPC](https://www.tamtam.ai/c/ppc) (dsainc.com)<br>PPC has merged with DSA, offering a unified approach to services and solutions previously provided by both companies | IT Services and IT Consulting | 🇺🇸 Trevose | 1,538 | 1963 |
| 34 | [Certara](https://www.tamtam.ai/c/certara) (certara.com)<br>This company accelerates medicine development by using biosimulation software, technology, and services to revolutionize drug discovery and development globally | Business Consulting and Services | 🇺🇸 Radnor | 1,514 |  |
| 35 | [System One](https://www.tamtam.ai/c/system-one) (systemone.com)<br>Specialized provider of outsourced services and workforce solutions for critical infrastructure, technology, life sciences, and government sectors Offering staffing and technical expertise | Business Consulting and Services | 🇺🇸 Pittsburgh | 1,507 |  |
| 36 | [Sharp Services](https://www.tamtam.ai/c/sharp-services) (sharpservices.com)<br>Provides commercial packaging, clinical services, and sterile manufacturing for pharmaceutical and biotech clients, covering R&D to market launch globally. | Pharmaceutical Manufacturing | 🇺🇸 Allentown | 1,506 | 1993 |
| 37 | [GHR Healthcare](https://www.tamtam.ai/c/ghr-healthcare) (ghrhealthcare.com)<br>GHR Healthcare is a partner in healthcare staffing, matching professionals with facilities through industry expertise, tech solutions, and personalized support | Staffing and Recruiting | 🇺🇸 Blue Bell | 1,500 | 1993 |
| 38 | [TestingXperts](https://www.tamtam.ai/c/testingxperts) (testingxperts.com)<br>A global leader in Quality Engineering and Digital Assurance services, offering a comprehensive range of testing solutions for Next Gen technologies | IT Services and IT Consulting | 🇺🇸 Mechanicsburg | 1,480 | 2013 |
| 39 | [Weston Solutions, Inc.](https://www.tamtam.ai/c/weston-solutions-inc) (westonsolutions.com)<br>A national environmental and infrastructure services firm providing excellence in remediation, compliance, water management, infrastructure improvements, and more for various clients | Professional Services | 🇺🇸 West Chester | 1,459 | 1957 |
| 40 | [CMA](https://www.tamtam.ai/c/cma) (core-states.com)<br>The company, now part of Core States Group, offers services related to engineering and architectural design Visit core-statescom for more information | Architecture and Planning | 🇺🇸 Ambler | 1,455 |  |
| 41 | [Lash Group](https://www.tamtam.ai/c/lash-group) (lashgroup.com)<br>A global pharmaceutical solutions company focused on improving health outcomes by optimizing market access to therapies for people and animals worldwide | Pharmaceutical Manufacturing | 🇺🇸 Conshohocken | 1,428 |  |
| 42 | [ESIS, Inc.](https://www.tamtam.ai/c/esis-inc) (esis.com)<br>Provider of risk management services including claims management, pre- and post-loss services, and integrated absence management, backed by a global insurance leader | Insurance | 🇺🇸 Philadelphia | 1,395 | 1953 |
| 43 | [2X](https://www.tamtam.ai/c/2x) (2x.marketing)<br>Provides AI-enabled marketing talent and strategic consulting through a subscription-based model to build, run, and optimize data-driven campaigns for lead generation. | Marketing Services | 🇺🇸 Malvern | 1,337 | 2017 |
| 44 | [TAIT](https://www.tamtam.ai/c/tait) (taittowers.com)<br>Global leader in creating world-class live experiences through precision engineering, technical innovation, and production for artists, brands, and venues worldwide | Entertainment Providers | 🇺🇸 Lititz | 1,329 | 1978 |
| 45 | [Pennoni](https://www.tamtam.ai/c/pennoni) (pennoni.com)<br>The firm partners with clients to deliver innovative, sustainable, and resilient engineering solutions, fostering long-term relationships focused on community impact | Engineering Services | 🇺🇸 Philadelphia | 1,317 | 1966 |
| 46 | [Buchanan Ingersoll & Rooney PC](https://www.tamtam.ai/c/buchanan-ingersoll-and-rooney-pc) (bipc.com)<br>National law firm providing legal, business, regulatory, and government relations advice to clients in energy, finance, healthcare, and life sciences industries | Law Practice | 🇺🇸 Pittsburgh | 1,272 | 1850 |
| 47 | [Marshall Dennehey](https://www.tamtam.ai/c/marshall-dennehey) (marshalldennehey.com)<br>A leading civil defense litigation law firm with 500 attorneys across 19 offices, specializing in various practice areas including professional liability, healthcare, and workers' compensation | Law Practice | 🇺🇸 Philadelphia | 1,261 | 1962 |
| 48 | [Mastech Digital](https://www.tamtam.ai/c/mastech-digital) (mastechdigital.com)<br>A Digital Transformation IT Services company offering expertise in data management, engineering, and science Provides top remote tech workers and custom digital learning programs | IT Services and IT Consulting | 🇺🇸 Moon Township | 1,248 | 1986 |
| 49 | [WebFX](https://www.tamtam.ai/c/webfx) (webfx.com)<br>A digital marketing agency providing SEO, web design, ecommerce, and conversion services to drive revenue and deliver ROI for clients globally | Advertising Services | 🇺🇸 Harrisburg | 1,242 | 1996 |
| 50 | [Integra Global Solutions Corp](https://www.tamtam.ai/c/integra-global-solutions-corp) (globalintegra.com)<br>A leading business process outsourcing and technology company offering AI automation and cloud solutions to drive cost reduction and efficiency for global clients | Outsourcing and Offshoring Consulting | 🇺🇸 Wexford | 1,214 | 2004 |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.

## More company lists in Pennsylvania

- [The largest companies in Pennsylvania](https://www.tamtam.ai/l/largest-companies-pennsylvania) (3,427)
- [Multinational companies in Pennsylvania](https://www.tamtam.ai/l/multinational-companies-pennsylvania) (472)
- [Education providers in Pennsylvania](https://www.tamtam.ai/l/education-companies-pennsylvania) (373)
- [Manufacturers in Pennsylvania](https://www.tamtam.ai/l/manufacturers-pennsylvania) (364)
- [Financial services firms in Pennsylvania](https://www.tamtam.ai/l/financial-services-firms-pennsylvania) (264)
- [Healthcare providers in Pennsylvania](https://www.tamtam.ai/l/healthcare-providers-pennsylvania) (264)
- [Companies with in-house R&D in Pennsylvania](https://www.tamtam.ai/l/r-and-d-companies-pennsylvania) (255)
- [Retail chains in Pennsylvania](https://www.tamtam.ai/l/retail-chains-pennsylvania) (246)
- [Hospitals and Health Care companies in Pennsylvania](https://www.tamtam.ai/l/hospitals-and-health-care-companies-pennsylvania) (243)
- [Critical infrastructure operators in Pennsylvania](https://www.tamtam.ai/l/critical-infrastructure-operators-pennsylvania) (225)
- [Hardware manufacturers in Pennsylvania](https://www.tamtam.ai/l/hardware-companies-pennsylvania) (173)
- [Higher Education companies in Pennsylvania](https://www.tamtam.ai/l/higher-education-companies-pennsylvania) (173)
- [IT Services and IT Consulting companies in Pennsylvania](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-pennsylvania) (172)
- [Financial Services companies in Pennsylvania](https://www.tamtam.ai/l/financial-services-companies-pennsylvania) (160)
- [IT services companies in Pennsylvania](https://www.tamtam.ai/l/it-services-companies-pennsylvania) (157)
- [Consulting firms in Pennsylvania](https://www.tamtam.ai/l/consulting-firms-pennsylvania) (144)
- [Companies with a mobile app in Pennsylvania](https://www.tamtam.ai/l/companies-with-mobile-app-pennsylvania) (130)
- [Family-owned companies in Pennsylvania](https://www.tamtam.ai/l/family-owned-companies-pennsylvania) (130)
- [Public sector organisations in Pennsylvania](https://www.tamtam.ai/l/public-sector-organisations-pennsylvania) (123)
- [Corporate groups and holding companies in Pennsylvania](https://www.tamtam.ai/l/holding-companies-pennsylvania) (120)
- [Publicly traded companies in Pennsylvania](https://www.tamtam.ai/l/publicly-traded-companies-pennsylvania) (116)
- [SaaS companies in Pennsylvania](https://www.tamtam.ai/l/saas-companies-pennsylvania) (114)
- [Construction companies in Pennsylvania](https://www.tamtam.ai/l/construction-companies-pennsylvania) (106)
- [Insurance companies in Pennsylvania](https://www.tamtam.ai/l/insurance-companies-pennsylvania) (101)

## The same list elsewhere in United States

- [Professional services firms in the United States](https://www.tamtam.ai/l/professional-services-firms-united-states) (7,078)
- [Professional services firms in New York State](https://www.tamtam.ai/l/professional-services-firms-new-york-state) (955)
- [Professional services firms in California](https://www.tamtam.ai/l/professional-services-firms-california) (880)
- [Professional services firms in Texas](https://www.tamtam.ai/l/professional-services-firms-texas) (629)
- [Professional services firms in Florida](https://www.tamtam.ai/l/professional-services-firms-florida) (375)
- [Professional services firms in Virginia](https://www.tamtam.ai/l/professional-services-firms-virginia) (344)
- [Professional services firms in Illinois](https://www.tamtam.ai/l/professional-services-firms-illinois) (339)
- [Professional services firms in Massachusetts](https://www.tamtam.ai/l/professional-services-firms-massachusetts) (249)
- [Professional services firms in New Jersey](https://www.tamtam.ai/l/professional-services-firms-new-jersey) (249)
- [Professional services firms in Georgia](https://www.tamtam.ai/l/professional-services-firms-georgia) (246)
- [Professional services firms in Ohio](https://www.tamtam.ai/l/professional-services-firms-ohio) (195)
- [Professional services firms in Maryland](https://www.tamtam.ai/l/professional-services-firms-maryland) (176)
- [Professional services firms in Michigan](https://www.tamtam.ai/l/professional-services-firms-michigan) (172)
- [Professional services firms in Washington State](https://www.tamtam.ai/l/professional-services-firms-washington-state) (163)
- [Professional services firms in North Carolina](https://www.tamtam.ai/l/professional-services-firms-north-carolina) (142)
- [Professional services firms in Alabama](https://www.tamtam.ai/l/professional-services-firms-alabama) (135)
- [Professional services firms in Minnesota](https://www.tamtam.ai/l/professional-services-firms-minnesota) (125)
- [Professional services firms in New York](https://www.tamtam.ai/l/professional-services-firms-new-york) (735)
- [Professional services firms in Chicago](https://www.tamtam.ai/l/professional-services-firms-chicago) (196)
- [Professional services firms in Houston](https://www.tamtam.ai/l/professional-services-firms-houston) (156)
- [Professional services firms in Atlanta](https://www.tamtam.ai/l/professional-services-firms-atlanta) (143)
- [Professional services firms in San Francisco](https://www.tamtam.ai/l/professional-services-firms-san-francisco) (130)
- [Professional services firms in Washington](https://www.tamtam.ai/l/professional-services-firms-washington) (109)
- [Professional services firms in Los Angeles](https://www.tamtam.ai/l/professional-services-firms-los-angeles) (108)

---

Source: https://www.tamtam.ai/l/professional-services-firms-pennsylvania