# List of professional services firms in Michigan

Tamtam tracks 172 professional services firms headquartered in Michigan. This list ranks the 50 largest by number of employees on LinkedIn, led by Gi Group, RGIS and HTC Global Services. Their median headcount is 1,315. Half of them were founded in 1983 or later. The most common headquarters are Troy (12), Detroit (10) and Ann Arbor (4).

This selection of professional services firms in Michigan includes several large, established companies, many of which provide IT services, business consulting, or specialized staffing and educational support. For example, HTC Global Services and Atos Syntel offer IT and business process services, while Kelly Education and Edustaff specialize in educational staffing. RGIS provides retail merchandising services, and Plante Moran is a professional services firm focusing on audit, tax, consulting, and wealth management.

A notable pattern among these firms is the strong presence of companies catering to the automotive industry, such as MSX International and Caresoft Global, reflecting Michigan's industrial heritage. There is also a concentration of headquarters in cities like Troy, Ann Arbor, and Detroit.

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

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Gi Group](https://www.tamtam.ai/c/gi-group) (gigroup.com)<br>Providing temporary, permanent, professional staffing, executive search, outsourcing, training, outplacement, and HR consultancy services worldwide across multiple industries. | Staffing and Recruiting | 🇺🇸 Milan | 17,915 |  |
| 2 | [RGIS](https://www.tamtam.ai/c/rgis) (rgis.com)<br>A global provider of accurate inventories and quality retail merchandising services, with nation-wide coverage and a passion for client satisfaction | Retail | 🇺🇸 Birmingham | 12,544 | 1958 |
| 3 | [HTC Global Services](https://www.tamtam.ai/c/htc-global-services) (htcinc.com)<br>Provider of IT and business process services using emerging technologies to enable clients' digital transformation and sustainable growth. | IT Services and IT Consulting | 🇺🇸 Troy | 10,143 | 1990 |
| 4 | [Kelly Education](https://www.tamtam.ai/c/kelly-education) (kellyeducation.com)<br>A leading workforce solutions company in education, specializing in placing talent from early childhood to higher education, including leadership roles | Education Administration Programs | 🇺🇸 Troy | 9,490 | 1997 |
| 5 | [Atos Syntel](https://www.tamtam.ai/c/atos-syntel) (atos-syntel.net)<br>Providing integrated IT and knowledge process services, focusing on automation, agile, cloud, analytics, IoT, and long-term client partnerships. | IT Services and IT Consulting | 🇺🇸 Troy | 6,789 |  |
| 6 | [Edustaff](https://www.tamtam.ai/c/edustaff) (edustaff.org)<br>An educational staffing company providing consolidated HR services to school districts, committed to innovation, excellence, and leaving a positive impact | Education Administration Programs | 🇺🇸 Grand Rapids | 6,116 |  |
| 7 | [Plante Moran](https://www.tamtam.ai/c/plante-moran) (plantemoran.com)<br>Professional services firm specializing in audit, tax, consulting, and wealth management with a strong focus on client relationships and support. | Accounting | 🇺🇸 Southfield | 4,664 | 1924 |
| 8 | [MSX International](https://www.tamtam.ai/c/msx-international) (msxi.com)<br>This company partners with automotive OEMs and mobility companies, providing support in retail strategies, dealer performance, repair optimization, and consumer engagement | Business Consulting and Services | 🇺🇸 Detroit | 4,448 |  |
| 9 | [NSF](https://www.tamtam.ai/c/nsf-ann-arbor) (nsf.org)<br>Protects and improves human health and the environment. Facilitates standards, certifies products, tests, audits, educates, and manages risks for global public health. | Public Safety | 🇺🇸 Ann Arbor | 3,397 | 1944 |
| 10 | [MMS](https://www.tamtam.ai/c/mms) (mmsholdings.com)<br>A global CRO specializing in clinical research services for pharmaceutical and biotech companies, focused on innovation, quality, and delivering life-changing therapies | Pharmaceutical Manufacturing | 🇺🇸 Canton | 3,136 | 2006 |
| 11 | [Miracle Software Systems, Inc](https://www.tamtam.ai/c/miracle-software-systems-inc) (miraclesoft.com)<br>Global IT services company delivering innovative solutions across Cloud, Application Development, Automation, Data Analytics, Integration, Cognitive, and Digital Experience technologies with strategic partnerships | IT Services and IT Consulting | 🇺🇸 Novi | 2,689 | 1994 |
| 12 | [Project Worldwide](https://www.tamtam.ai/c/project-worldwide) (project.com)<br>Creative alliance combining multiple agencies focused on ambitious collaboration and meaningful work through hyperconnected creativity and diverse marketing expertise. | Advertising Services | 🇺🇸 Auburn Hills | 2,678 |  |
| 13 | [PINKERTON \| Comprehensive Risk Management](https://www.tamtam.ai/c/pinkerton-comprehensive-risk-management) (pinkerton.com)<br>A global provider of security and risk management solutions with a strong reputation, offering a wide range of services worldwide | Security and Investigations | 🇺🇸 Ann Arbor | 2,119 | 1850 |
| 14 | [SmithGroup](https://www.tamtam.ai/c/smithgroup) (smithgroup.com)<br>Innovative design & engineering firm using research, technology, and design thinking to tackle challenges in architecture, engineering, and environmental science globally | Architecture and Planning | 🇺🇸 Detroit | 1,926 | 1853 |
| 15 | [Caresoft Global](https://www.tamtam.ai/c/caresoft-global) (caresoftglobal.com)<br>Global engineering solutions company partnering with automotive and equipment manufacturers to address product development, cost optimization, manufacturing, and aftermarket needs with specialized expertise and experience | Business Consulting and Services | 🇺🇸 Livonia | 1,820 |  |
| 16 | [George P Johnson Experience Marketing](https://www.tamtam.ai/c/george-p-johnson-experience-marketing) (gpj.com)<br>Strategic experience marketing agency creating integrated experiential programs through digital, mobile, and physical brand activations to accelerate relationships with customers and industry influencers. | Advertising Services | 🇺🇸 Auburn Hills | 1,722 | 1914 |
| 17 | [Atwell, LLC](https://www.tamtam.ai/c/atwell-llc) (atwell.com)<br>Full-service consulting, engineering, and construction firm providing customized solutions for real estate, land development, power, energy, and oil markets. | Civil Engineering | 🇺🇸 Southfield | 1,673 |  |
| 18 | [Infotree Global Solutions](https://www.tamtam.ai/c/infotree-global-solutions) (infotreeglobal.com)<br>Connecting top talent with leading companies globally, specializing in IT, engineering, clinical, skilled trades, finance, and accounting sectors. | Staffing and Recruiting | 🇺🇸 Plymouth | 1,627 | 2002 |
| 19 | [Creative Synergies Group](https://www.tamtam.ai/c/creative-synergies-group) (global-csg.com)<br>A leading digital innovation solution provider, leveraging expertise and NextGen technologies to empower global customers in Industry 40 revolution | IT Services and IT Consulting | 🇺🇸 Okemos | 1,617 | 2011 |
| 20 | [Clark Hill Law](https://www.tamtam.ai/c/clark-hill-law) (clarkhill.com)<br>A diverse and talented team at the forefront of legal services, partnering with clients to achieve their business objectives in varied locations | Law Practice | 🇺🇸 Detroit | 1,579 | 1890 |
| 21 | [KellyOCG](https://www.tamtam.ai/c/kellyocg) (kellyocg.com)<br>Global advisor of talent supply chain strategies and workforce solutions, aligning talent strategy with business goals to help companies and careers thrive | Business Consulting and Services | 🇺🇸 Troy | 1,544 |  |
| 22 | [Rehmann](https://www.tamtam.ai/c/rehmann) (rehmann.com)<br>A professional advisory firm offering accounting, assurance, business solutions, specialized consulting, and wealth management services with over 80 years of experience | Financial Services | 🇺🇸 Troy | 1,415 | 1941 |
| 23 | [Kelly Science, Engineering, Technology & Telecom](https://www.tamtam.ai/c/kelly-science-engineering-technology-and-telecom) (set.kellyservices.us)<br>Helping companies adapt and succeed through their people, Kelly Science, Engineering and Technology provides innovative solutions for success | Staffing and Recruiting | 🇺🇸 Troy | 1,412 |  |
| 24 | [The Private Firm](https://www.tamtam.ai/c/the-private-firm) (thefirm.net)<br>The Private Firm provides experienced legal services to business owners, executives, and managers, helping them navigate opportunities, overcome difficulties, and achieve their goals | Legal Services | 🇺🇸 Rochester | 1,354 | 2020 |
| 25 | [Escalent](https://www.tamtam.ai/c/escalent) (escalent.co)<br>A data analytics and advisory firm guiding leading brands in various industries through market insights to drive growth and transformation | Market Research | 🇺🇸 Livonia | 1,315 |  |
| 26 | [Netlink Software Group America Inc](https://www.tamtam.ai/c/netlink-software-group-america-inc) (netlink.com)<br>A global technology services provider delivering innovative solutions in automation, ERP, BI & analytics, AI, cloud, mobility, BPO, ESG management, and more | IT Services and IT Consulting | 🇺🇸 Madison Heights | 1,309 | 1998 |
| 27 | [ICONMA](https://www.tamtam.ai/c/iconma) (iconma.com)<br>A woman-owned staffing company providing professional staffing services, project-based solutions, and a wide range of expertise to Fortune 500 organizations globally | Staffing and Recruiting | 🇺🇸 Troy | 1,272 | 2000 |
| 28 | [CCI Systems](https://www.tamtam.ai/c/cci-systems) (ccisystems.com)<br>An employee-owned solution provider offering telecommunications solutions, network assessments, engineering, drafting, design services, and 24/7 support to achieve strategic goals | Telecommunications | 🇺🇸 Iron Mountain | 1,256 |  |
| 29 | [Dickinson Wright](https://www.tamtam.ai/c/dickinson-wright) (dickinson-wright.com)<br>A full-service legal firm with over 500 lawyers, offering unmatched client service and high-quality advice in 40 practice areas globally | Law Practice | 🇺🇸 Detroit | 1,243 | 1878 |
| 30 | [Second To None](https://www.tamtam.ai/c/second-to-none) (second-to-none.com)<br>Empowering customer-centric companies to create authentic experiences through mystery shopping, compliance, and voice of customer solutions for diverse sectors | Market Research | 🇺🇸 Ann Arbor | 1,223 | 1989 |
| 31 | [Strategic Staffing Solutions](https://www.tamtam.ai/c/strategic-staffing-solutions) (strategicstaff.com)<br>A global IT consulting and business services corporation offering staff augmentation, managed services, workforce management, and recruiting with industry expertise | IT Services and IT Consulting | 🇺🇸 Detroit | 1,205 | 1990 |
| 32 | [RGBSI](https://www.tamtam.ai/c/rgbsi) (rgbsi.com)<br>Delivering engineering and quality solutions globally, bridging strategy and execution with in-house technologies to enhance performance and drive innovation | Engineering Services | 🇺🇸 Troy | 1,198 | 1997 |
| 33 | [Global LT, Inc.](https://www.tamtam.ai/c/global-lt-inc) (global-lt.com)<br>A leading expert in Language Solutions and Expatriate Services, offering training, translation, interpretation, and destination services worldwide since 1979 | Education Administration Programs | 🇺🇸 Troy | 1,098 | 1979 |
| 34 | [GalaxE.Solutions](https://www.tamtam.ai/c/galaxe-solutions) (info.endava.com)<br>Global professional services company offering a variety of services under well-known brands, focused on outsourcing and technology solutions | IT Services and IT Consulting | 🇺🇸 Detroit | 1,092 | 1990 |
| 35 | [Altran Engineering Solutions](https://www.tamtam.ai/c/altran-engineering-solutions) (altranengineeringsolutions.com)<br>Global engineering solutions provider offering services in transportation, consumer, industrial, and medical sectors Specializing in embedded systems, design, prototyping, testing, and manufacturing | Motor Vehicle Manufacturing | 🇺🇸 Livonia | 1,090 | 2006 |
| 36 | [Production Modeling Corporation (PMC)](https://www.tamtam.ai/c/production-modeling-corporation-pmc) (pmcorp.com)<br>Since 1979, PMC has provided expert software, consulting, training, support, and staffing solutions for operations, engineering, supply chain management, and more | Business Consulting and Services | 🇺🇸 Dearborn | 931 | 1979 |
| 37 | [Doeren Mayhew](https://www.tamtam.ai/c/doeren-mayhew) (doeren.com)<br>Professionals providing guidance and direction to businesses and nonprofit organizations to traverse complex business terrain. Offers audit, tax, and business consulting services. | Accounting | 🇺🇸 Troy | 929 | 1932 |
| 38 | [EDSI](https://www.tamtam.ai/c/edsi) (edsi.com)<br>A national workforce development, training, and consulting company helping individuals and organizations transition to employment and self-sufficiency, with over 45 years of experience | Professional Training and Coaching | 🇺🇸 Dearborn | 911 | 1979 |
| 39 | [Honigman LLP](https://www.tamtam.ai/c/honigman-llp) (honigman.com)<br>Leading business law firm with extensive experience counseling clients in various legal areas, known for innovative approaches, exceptional client service, and top-tier practice rankings | Law Practice | 🇺🇸 Detroit | 892 | 1948 |
| 40 | [Health Management Associates](https://www.tamtam.ai/c/health-management-associates) (healthmanagement.com)<br>Health Management Associates is a national research and consulting firm specializing in health care program and policy issues for various organizations | Hospitals and Health Care | 🇺🇸 Okemos | 882 | 1985 |
| 41 | [OneMagnify](https://www.tamtam.ai/c/onemagnify) (onemagnify.com)<br>Innovative company combining technology, creativity, and analytics to help build and transform brands that are making a global impact | Advertising Services | 🇺🇸 Detroit | 834 | 1967 |
| 42 | [Wade Trim](https://www.tamtam.ai/c/wade-trim) (wadetrim.com)<br>The company specializes in solving engineering challenges to enhance infrastructure, create stronger communities, and deliver customized solutions with excellent communication | Civil Engineering | 🇺🇸 Detroit | 817 | 1926 |
| 43 | [Urban Science](https://www.tamtam.ai/c/urban-science) (urbanscience.com)<br>Provide scientific analysis and insights to solve automotive market challenges, helping clients improve targeting, sales, market share, and profitability. | Motor Vehicle Manufacturing | 🇺🇸 Detroit | 812 | 1977 |
| 44 | [Multi-Training Systems LLC](https://www.tamtam.ai/c/multi-training-systems-llc) (mtsinfo.com)<br>A learning organization specializing in diversity, equity, and inclusion training and consulting for individuals, teams, and organizations across various industries | Professional Training and Coaching | 🇺🇸 Southfield | 790 | 1994 |
| 45 | [Trillium Staffing Solutions](https://www.tamtam.ai/c/trillium-staffing-solutions) (trilliumstaffing.com)<br>An employment service specializing in staffing, training, on-site services, human resources, and safety consulting, dedicated to providing quality employees and service | Staffing and Recruiting | 🇺🇸 Kalamazoo | 779 | 1984 |
| 46 | [OHM Advisors](https://www.tamtam.ai/c/ohm-advisors) (ohm-advisors.com)<br>AEP firm specializing in community advancement through multidisciplinary teamwork in architecture, engineering, and planning Award-winning work creating great places | Architecture and Planning | 🇺🇸 Livonia | 754 | 1962 |
| 47 | [TekWissen ®](https://www.tamtam.ai/c/tekwissen) (tekwissen.com)<br>Global provider of technology consulting, workforce management, and recruitment solutions with a focus on exceeding client expectations and driving innovation | IT Services and IT Consulting | 🇺🇸 Ann Arbor | 749 | 2009 |
| 48 | [Ghafari Associates](https://www.tamtam.ai/c/ghafari-associates) (ghafari.com)<br>Since 1982, this company offers integrated design solutions for various sectors globally, with services in architecture, engineering, and operations | Architecture and Planning | 🇺🇸 Dearborn | 741 | 1982 |
| 49 | [Populus Group](https://www.tamtam.ai/c/populus-group) (populusgroup.com)<br>A company specializing in managing contingent workforces, offering payroll, MSP, staffing, and recruitment services with a focus on diversity and opportunity for all | Staffing and Recruiting | 🇺🇸 Troy | 704 | 2002 |
| 50 | [Job Center](https://www.tamtam.ai/c/job-center) (jobcentermichigan.com)<br>A family-owned staffing company serving Metro Detroit and surrounding areas since 1983, specializing in temporary-to-hire placements | Human Resources Services | 🇺🇸 Troy | 703 | 1983 |

## 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 Michigan

- [The largest companies in Michigan](https://www.tamtam.ai/l/largest-companies-michigan) (2,600)
- [Multinational companies in Michigan](https://www.tamtam.ai/l/multinational-companies-michigan) (468)
- [Manufacturers in Michigan](https://www.tamtam.ai/l/manufacturers-michigan) (454)
- [Companies with in-house R&D in Michigan](https://www.tamtam.ai/l/r-and-d-companies-michigan) (287)
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- [Hardware manufacturers in Michigan](https://www.tamtam.ai/l/hardware-companies-michigan) (238)
- [Education providers in Michigan](https://www.tamtam.ai/l/education-companies-michigan) (211)
- [Retail chains in Michigan](https://www.tamtam.ai/l/retail-chains-michigan) (201)
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- [Financial services firms in Michigan](https://www.tamtam.ai/l/financial-services-firms-michigan) (154)
- [Critical infrastructure operators in Michigan](https://www.tamtam.ai/l/critical-infrastructure-operators-michigan) (150)
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- [Contract manufacturers in Michigan](https://www.tamtam.ai/l/contract-manufacturers-michigan) (133)
- [Public sector organisations in Michigan](https://www.tamtam.ai/l/public-sector-organisations-michigan) (132)
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- [Financial Services companies in Michigan](https://www.tamtam.ai/l/financial-services-companies-michigan) (100)
- [Companies with a mobile app in Michigan](https://www.tamtam.ai/l/companies-with-mobile-app-michigan) (95)
- [Corporate groups and holding companies in Michigan](https://www.tamtam.ai/l/holding-companies-michigan) (90)
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## 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)
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- [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 Pennsylvania](https://www.tamtam.ai/l/professional-services-firms-pennsylvania) (245)
- [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 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)

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