Critical infrastructure operators headquartered in Wisconsin (2026 list)

#	Company	Industry	Headquarters	Employees	Founded
1	Northwestern Mutual northwesternmutual.com Financial planning and wealth management through life insurance, disability income, annuities, brokerage services, and discretionary portfolio management for over four million clients worldwide.	Financial Services	🇺🇸 Milwaukee	37,457	1857
2	Advocate Aurora Health advocateaurorahealth.org An integrated health system providing high-quality care, clinical innovation, and research studies, with a strong focus on academic partnerships and community benefits	Hospitals and Health Care	🇺🇸 Milwaukee	15,279	2018
3	Aurora Health Care careers.aah.org Nonprofit integrated health system providing clinical innovation, specialized care, research, education, and community benefits across multiple states.	Hospitals and Health Care	🇺🇸 Milwaukee	13,816	n/a
4	Schneider schneider.com A premier transportation and logistics provider with a broad portfolio, delivering superior customer experiences for over 80 years	Truck Transportation	🇺🇸 Green Bay	11,650	1935
5	UW Health uwhealth.org Integrated academic health system operating multiple hospitals and clinics, providing care to over 832,000 patients annually in Wisconsin and Illinois.	Hospitals and Health Care	🇺🇸 Madison	10,155	n/a
6	First Data Corporation fiserv.com A global leader in payments and financial technology, serving financial institutions, merchants, and businesses worldwide	IT Services and IT Consulting	🇺🇸 Brookfield	9,745	1984
7	Banking Industry legacybancorp.com A financial services company dedicated to increasing shareholder value, providing excellent customer service, increasing homeownership, and developing the economic base of communities	Banking	🇺🇸 Milwaukee	5,348	n/a
8	Associated Bank associatedbank.com Provides comprehensive financial products and services through over 200 locations across Wisconsin, Illinois, Minnesota, and loan offices in several other states.	Financial Services	🇺🇸 Green Bay	5,089	1861
9	Marshfield Clinic Health System marshfieldclinic.org Providing comprehensive healthcare services, research, education, and community partnerships across rural Wisconsin and Michigan's Upper Peninsula.	Hospitals and Health Care	🇺🇸 Marshfield	5,019	1916
10	Gundersen Health System gundersenhealth.org Not-for-profit healthcare network delivering primary, specialty, and emergency care across multiple hospitals and clinics in the Midwest region.	Hospitals and Health Care	🇺🇸 La Crosse	4,991	1891
11	Froedtert Health froedtert.com Academic medical center with multiple hospitals and clinics providing patient care, medical research, education, and trauma services across Wisconsin.	Hospitals and Health Care	🇺🇸 Milwaukee	4,892	n/a
12	ThedaCare thedacare.org A non-profit healthcare organization in northeast Wisconsin with seven hospitals, 35 clinics, and Mayo Clinic affiliation, providing serious and complex healthcare to over 235,000 patients annually	Hospitals and Health Care	🇺🇸 Neenah	4,097	1909
13	Aspirus Health aspirus.org A non-profit health system in Wisconsin and Upper Michigan with hospitals, clinics, home health care, pharmacies, and a network of physicians	Hospitals and Health Care	🇺🇸 Wausau	4,095	n/a
14	TDS®tdsinc.com Provides broadband internet, TV, phone services, wireless infrastructure leasing, and marketing solutions to urban, suburban, and rural U.S. communities.	Telecommunications	🇺🇸 Madison	3,980	1969
15	Michels Corporation michels.us A family-owned global leader in energy and infrastructure construction, providing engineering, procurement, and construction services with a focus on modern solutions	Construction	🇺🇸 Brownsville	3,914	1959
16	Marshfield Clinic marshfieldclinic.org A large private multispecialty group practice with 775 physicians in 80 specialties across Wisconsin and Michigan's Upper Peninsula	Hospitals and Health Care	🇺🇸 Marshfield	3,282	1916
17	ProHealth Care careers.prohealthcare.org A healthcare company in Wisconsin that values its employees, offers a supportive culture, generous benefits, and opportunities for education to provide exceptional patient care	Hospitals and Health Care	🇺🇸 Waukesha	3,227	1914
18	WEC Energy Group wecenergygroup.com Provides electric and natural gas services to millions of customers across multiple states, focusing on reliability, customer care, and operational efficiency.	Utilities	🇺🇸 Milwaukee	3,080	2015
19	TDS Telecommunications LLC tdstelecom.com Provides high-speed internet, TV entertainment, phone services, VoIP solutions, and data networking to urban, suburban, and rural communities.	Telecommunications	🇺🇸 Madison	2,985	1969
20	Milwaukee County county.milwaukee.gov Management and operation of public services including airport, courts, human services, parks, public safety, transportation, and support for seniors and veterans.	Government Administration	🇺🇸 Milwaukee	2,975	n/a
21	We Energies we-energies.com A leading energy company serving over 11 million electric and natural gas customers in Wisconsin and Michigan, with a focus on reliability and customer satisfaction	Utilities	🇺🇸 Milwaukee	2,832	1896
22	Alliant Energy alliantenergy.com Provides regulated electric and natural gas services to retail customers in Iowa and Wisconsin with focus on sustainability and community.	Utilities	🇺🇸 Madison	2,626	1917
23	Bellin Health bellin.org A premier health system in Northeast Wisconsin and Michigan, offering expertise in cardiac care, orthopedics, sports medicine, mental health, and primary care services	Hospitals and Health Care	🇺🇸 Green Bay	2,509	1907
24	UnityPoint Health – Meriter unitypoint.org UnityPoint Health - Meriter provides high-quality healthcare services, including hospital care, clinics, home health care, laboratories, and community philanthropic activities in Wisconsin	Hospitals and Health Care	🇺🇸 Madison	2,390	1898
25	Versiti Inc.versiti.org Blood health innovators focused on discovery, diagnosis, and treatment, conducting groundbreaking research and providing life-saving donations to communities and healthcare partners nation-wide	Hospitals and Health Care	🇺🇸 Milwaukee	2,047	n/a
26	Marten Transport marten.com A leading provider of refrigerated truckload, intermodal, and brokerage services in North America, focusing on reliability, savings, and customer satisfaction	Truck Transportation	🇺🇸 Mondovi	2,020	1946
27	City of Madison, WI cityofmadison.com Provides diverse public sector jobs supporting city residents through various departments, emphasizing customer service, equity, teamwork, and continuous improvement.	Government Administration	🇺🇸 Madison	1,840	1836
28	CUNA Mutual Group cunamutual.com Financially strong insurance, investment, and financial services company focused on creating a more equitable financial system through community engagement and products	Financial Services	🇺🇸 Madison	1,816	1934
29	Prevea Health prevea.com A multispecialty physician group in Northeast Wisconsin providing patient-centered care with a focus on innovation, compassion, and teamwork	Hospitals and Health Care	🇺🇸 Green Bay	1,421	1996
30	Columbia St. Mary's healthcare.ascension.org A faith-based healthcare organization providing compassionate care to all, with a focus on those in poverty and vulnerable populations	Hospitals and Health Care	🇺🇸 Milwaukee	1,419	1849
31	University of Wisconsin Hospital and Clinics uwhealth.org A prestigious academic medical center with 471 beds, specializing in cancer treatment, pediatrics, ophthalmology, surgical specialties, and organ transplantation	Hospitals and Health Care	🇺🇸 Madison	1,378	n/a
32	Johnson Financial Group johnsonfinancialgroup.com Provides banking, wealth management, mortgage, leasing, and advisory services with strong community values and private family ownership.	Financial Services	🇺🇸 Racine	1,333	1970
33	WPS Health Insurance wpshealth.com A leading health insurance provider in Wisconsin offering PPO and HDHP plans, Medicare supplement options, and comprehensive provider networks	Insurance	🇺🇸 Madison	1,274	1946
34	Froedtert South froedtertsouth.com A regional healthcare system in southeastern Wisconsin and northern Illinois, dedicated to providing compassionate healthcare services and promoting well-being for all	Hospitals and Health Care	🇺🇸 Kenosha	1,268	1903
35	SSM Health St. Mary’s Hospital – Madison stmarysmadison.com Medical facility offering comprehensive healthcare services in South Central Wisconsin since 1912, including inpatient, outpatient, and specialty care	Hospitals and Health Care	🇺🇸 Madison	1,201	n/a
36	Dean Clinic ssmhealth.com Integrated healthcare organization based in Madison, Wisconsin, providing medical services, health insurance, ancillary services, and eye care across southern Wisconsin	Hospitals and Health Care	🇺🇸 Madison	1,097	1904
37	Agnesian HealthCare agnesian.com A locally based, not-for-profit integrated healthcare system sponsored by the Congregation of Sisters of St Agnes, providing compassionate care and various healthcare services	Hospitals and Health Care	🇺🇸 Fond du Lac	1,071	1896
38	Air Wisconsin Airlines airwis.com Regional airline in the US since 1965, now operating as American Eagle with partner American Airlines, serving the Midwest and East Coast	Airlines and Aviation	🇺🇸 Appleton	1,035	1965
39	HSHS St. Vincent Hospital Green Bay hshs.org Leading hospital in Northeast Wisconsin with cutting-edge prevention, diagnostic, and treatment procedures, top technology, and skilled medical professionals	Hospitals and Health Care	🇺🇸 Green Bay	999	1888
40	WaterStone Bank wsbonline.com Established in 1921, this community bank offers personal and business banking products with numerous branches and is the parent company to Waterstone Mortgage	Banking	🇺🇸 Wauwatosa	923	1921
41	ATC atcllc.com Transmission-only electric utility serving parts of Wisconsin, Michigan, Minnesota, and Illinois, ensuring reliable power for 5 million customers while leading the transition to sustainable energy	Utilities	🇺🇸 Waukesha	869	2001
42	Tamarack Health tamarackhealth.org Providing excellent care throughout life, including hospital, clinics, long term care, and housing options, to support independence and healing	Hospitals and Health Care	🇺🇸 Hayward	821	n/a
43	Nicolet National Bank nicoletbank.com Community bank offering commercial lending, private and retail banking services with personalized customer service across multiple regional locations.	Banking	🇺🇸 Green Bay	814	2000
44	UW Credit Union uwcu.org A financial institution dedicated to putting members first, with a compassionate culture, professional development, and a focus on work-life balance	Banking	🇺🇸 Madison	812	1931
45	Landmark Credit Union landmarkcu.com A customer-owned financial cooperative serving Southern Wisconsin, Northeastern Illinois, and businesses, offering exceptional rates, personalized service, and lower fees	Financial Services	🇺🇸 Brookfield	807	1933
46	Summit Credit Union summitcreditunion.com Empowering individuals to improve financial well-being through honest advice, building relationships, and providing real solutions as a not-for-profit financial cooperative	Banking	🇺🇸 Madison	782	1935
47	Royal Credit Union rcu.org A credit union founded in 1964 to serve employees, now with over 300,000 members, focused on community values and providing financial assistance	Financial Services	🇺🇸 Eau Claire	686	1964
48	Clement J. Zablocki VA Medical Center va.gov The medical center provides comprehensive medical care, including primary, secondary, and tertiary services, to veterans in southeastern and east central Wisconsin	Hospitals and Health Care	🇺🇸 Milwaukee	662	1867
49	Versiti Blood Center of Wisconsin versiti.org This company based in Milwaukee provides blood and blood products to hospitals, delivering life-saving solutions and enhancing people's lives	Hospitals and Health Care	🇺🇸 Milwaukee	595	1947
50	Beloit Health System beloithealthsystem.org An independent community health system in northern Illinois and southern Wisconsin offering world-class facilities and services to improve community health	Hospitals and Health Care	🇺🇸 Beloit	589	n/a
51	Affinity Health System healthcare.ascension.org A faith-based healthcare organization dedicated to providing compassionate care, serving communities in need, and promoting innovation in healthcare delivery	Hospitals and Health Care	🇺🇸 Glendale	584	n/a
52	Fort HealthCare forthealthcare.com Fort HealthCare provides comprehensive healthcare services in Jefferson County, including inpatient care, specialty clinics, emergency services, and a sliding fee schedule for those in need	Hospitals and Health Care	🇺🇸 Fort Atkinson	579	1949
53	Madison Gas and Electric mge.com Regulated natural gas and electric utility serving Dane County and surrounding areas, committed to providing energy to the community since 1855	Utilities	🇺🇸 Madison	579	1896
54	HSHS St. Mary's Hospital Medical Center hshs.org A leading healthcare facility in Northeast Wisconsin offering orthopedic, digestive, cardiac, women's and child care, emergency, and diagnostic services with a focus on holistic healing	Hospitals and Health Care	🇺🇸 Green Bay	576	1900
55	Monroe Clinic monroeclinic.org A Catholic, not-for-profit health care network offering a wide range of services in southern Wisconsin and northern Illinois, with awards for quality and service	Hospitals and Health Care	🇺🇸 Monroe	525	1939
56	First Business Bank firstbusiness.bank A company offering business banking, private wealth management, bank consulting services, and total rewards for employees, committed to supporting communities	Financial Services	🇺🇸 Madison	485	1990
57	Dairyland Power Cooperative dairylandpower.com A generation and transmission cooperative providing safe, reliable, and sustainable electricity to cooperative members in the Upper Midwest region	Utilities	🇺🇸 La Crosse	476	1941
58	U.S. Energy us-energy.com A vertically integrated energy solutions provider offering refined products, alternative fuels, and environmental credits to help organizations achieve economic and environmental goals	Transportation, Logistics, Supply Chain and Storage	🇺🇸 Appleton	402	1951
59	Educators Credit Union linktr.ee A member-focused credit union in Southeast Wisconsin, offering fair interest rates, quality service, and opportunities for employees to grow and succeed	Financial Services	🇺🇸 Mount Pleasant	383	1937
60	National Bank of Commerce (WI/MN)nbcbanking.com A local community bank with over $1 billion in assets, offering personal banking, commercial banking, mortgage solutions, and signature banking services	Banking	🇺🇸 Superior	256	1934
61	Horicon Bank horiconbank.com Established in 1896, this bank has expanded to multiple locations, offering a variety of financial services to individuals and businesses in their communities	Financial Services	🇺🇸 Horicon	193	1896
62	Peoples State Bank peoplesfinancial.com A customer-centric bank offering a mix of community service and modern technology for seamless banking experiences like savings, loans, and online banking	Banking	🇺🇸 Prairie du Chien	166	1914
63	Blackhawk Bank blackhawkbank.com A regional bank providing a wide range of banking services to individuals, families, and businesses, with a focus on exceptional customer experiences and community involvement	Banking	🇺🇸 Beloit	89	n/a
64	State Bank of Chilton statebankofchilton.com Providing financial expertise and exceptional customer service, offering free checking accounts, investment options, student banking, small business loans, and retirement planning	Banking	🇺🇸 Chilton	34	1891
65	QuiCK Transport, LLC qcktrans.com Trucking and logistics company based in Wisconsin, with a mix of company drivers and owner operators serving clients across North America	Truck Transportation	🇺🇸 Kaukauna	29	2009
66	Northwestern Mutual Financial Network northwesternmutual.com This company provides financial security solutions such as life insurance, disability insurance, investment management, and financial services to help clients secure their future	Insurance	🇺🇸 Milwaukee	23	2007
67	Center Gas centerpointenergy.com A domestic energy delivery company offering electric transmission, natural gas distribution, competitive sales, and interstate pipelines and field services operations	Facilities Services	🇺🇸 Milwaukee	22	n/a
68	FLASH Family of Companies theflashfamily.com Family-owned dry bulk carrier specializing in trucking, transloading, and rail transportation of dry bulk commodities since 1984	Truck Transportation	🇺🇸 Green Lake	14	1984

Turn this list into pipeline

Tamtam finds the decision-makers at every company on a list like this one, with verified emails, phone numbers and the buying signals that tell you when to reach out.

Build your own list, free

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 Oct 24, 2026.

Critical infrastructure operators headquartered in Wisconsin

Turn this list into pipeline

How this list is built

More company lists in Wisconsin

The same list elsewhere in United States