Critical infrastructure operators headquartered in Connecticut (2026 list)

#	Company	Industry	Headquarters	Employees	Founded
1	Spectrum spectrum.net A leading broadband connectivity company offering internet, TV, mobile, voice, and tailored advertising services to residential, business, and government customers	Telecommunications	🇺🇸 Stamford	97,651	1993
2	Aetna, a CVS Health Company aetna.com A leading health care benefits company focused on making health care easy, affordable, and personalized Promoting diversity, inclusion, and community well-being	Wellness and Fitness Services	🇺🇸 Hartford	40,685	n/a
3	XPO xpo.com A global transportation company offering top-tier solutions to leading companies, with diverse opportunities for career growth and impactful work	Truck Transportation	🇺🇸 Greenwich	38,917	n/a
4	Charter Communications charter.com Provider of internet, television, and phone services, delivering innovative telecommunications solutions to residential and business customers nationwide.	Telecommunications	🇺🇸 Stamford	33,550	n/a
5	Cigna Healthcare cigna.com Benefits provider, guides customers through healthcare system, empowering them with information and insight to improve health and vitality.	Hospitals and Health Care	🇺🇸 Bloomfield	29,662	n/a
6	Time Warner Cable jobs.spectrum.com A leading TV, internet, and voice provider, focused on growth and exceptional service Visit our LinkedIn and policy page for more information	Telecommunications	🇺🇸 Stamford	16,207	n/a
7	Synchrony synchrony.com provides consumer financing solutions enabling millions to access essential needs and connects them with small businesses and health providers	Financial Services	🇺🇸 Stamford	16,106	n/a
8	Hartford HealthCare hartfordhealthcare.org Providing comprehensive healthcare services including hospitals, behavioral health, physician groups, urgent care, home care, and specialized medical institutes across Connecticut.	Hospitals and Health Care	🇺🇸 Hartford	10,736	n/a
9	Yale New Haven Hospital ynhh.org Academic medical center with extensive specialties, trauma, transplant, cancer, pediatric, psychiatric services, nursing excellence, and advanced technology integration.	Hospitals and Health Care	🇺🇸 New Haven	9,266	1826
10	Eversource Energy eversource.com A Fortune 500 energy company in New England, prioritizing safety, reliability, environmental leadership, and energy options for millions of customers	Utilities	🇺🇸 Hartford	8,353	n/a
11	Nuvance Health nuvancehealth.org Nonprofit hospital system offering healthcare services in the Hudson Valley and western Connecticut through award-winning hospitals, outpatient services, and medical practices	Hospitals and Health Care	🇺🇸 Danbury	7,335	n/a
12	Avangrid avangrid.com A leading sustainable energy company with a focus on transitioning America to a clean future through its Networks and Renewables businesses	Utilities	🇺🇸 Orange	7,096	n/a
13	Spectrum Business spectrum.com Provider of fast and reliable internet, phone, and mobile services tailored for small businesses, ensuring seamless communication and connectivity	Telecommunications	🇺🇸 Stamford	6,774	n/a
14	Yale New Haven Health ynhhs.org A healthcare organization with five hospitals offering advanced medical treatments, research, and innovations, along with access to primary care physicians and specialists	Hospitals and Health Care	🇺🇸 New Haven	5,708	1996
15	Webster Bank websterbank.com A leading commercial bank providing financial solutions to businesses, individuals, and families through digital and traditional services in three distinct lines of business	Banking	🇺🇸 Stamford	5,616	1935
16	Spectrum Enterprise spectrum.com A national provider of scalable, fiber-based technology solutions for businesses and communications service providers, offering Internet, Ethernet, Voice, TV, and Managed IT solutions	Telecommunications	🇺🇸 Stamford	5,583	n/a
17	Hartford Hospital hartfordhospital.org A leading healthcare provider in New England, offering high-quality care across various clinical disciplines including mental health services and long-term care	Hospitals and Health Care	🇺🇸 Hartford	4,932	1854
18	UConn Health health.uconn.edu Provides healthcare, medical and dental education, and conducts research. Operates a hospital, medical group, and dental practices across Connecticut.	Hospitals and Health Care	🇺🇸 Farmington	4,353	1961
19	Interactive Brokers interactivebrokers.com Provides automated trade execution and custody for diverse financial instruments across global markets, offering advanced tools and research at low cost.	Financial Services	🇺🇸 Greenwich	3,506	n/a
20	Saint Francis Hospital trinityhealthofne.org A major teaching hospital in Connecticut part of a large Catholic healthcare system, offering comprehensive medical services and specialized centers of excellence	Hospitals and Health Care	🇺🇸 Hartford	3,326	1897
21	Community Health Center chc1.com A leading provider of primary medical, dental, and mental health services to uninsured and underinsured individuals, using innovative service delivery models and technology	Hospitals and Health Care	🇺🇸 Middletown	2,864	1972
22	Connecticut Children's connecticutchildrens.org A leading pediatric academic medical center dedicated to advancing pediatric care through medical innovation, technology, research, and specialized healthcare services	Hospitals and Health Care	🇺🇸 Hartford	2,621	1996
23	Stamford Health stamfordhealth.org A not-for-profit healthcare organization in Stamford, CT providing high-quality health & wellness services, specialized orthopedic care, cancer treatment, and medical education	Hospitals and Health Care	🇺🇸 Stamford	2,565	1896
24	People's United Bank, N.A.mtb.com A regional bank offering commercial and retail banking, wealth management services, with over 400 locations across the Northeast	Financial Services	🇺🇸 Bridgeport	2,555	1842
25	Middlesex Health middlesexhealth.org A not-for-profit healthcare network in Connecticut, offering a magnet hospital, cancer centers, emergency and urgent care services, and specialized medical care	Hospitals and Health Care	🇺🇸 Middletown	2,436	1904
26	Bridgeport Hospital bridgeporthospital.org Private, not-for-profit acute care hospital in Connecticut's most populous city Offers burn care, various medical specialties, and is part of a larger healthcare system	Hospitals and Health Care	🇺🇸 Bridgeport	2,146	1878
27	Trinity Health Of New England trinityhealthofne.org Integrated health care delivery system in New England with world-class providers and facilities, focusing on better health, care, and lower costs for patients	Hospitals and Health Care	🇺🇸 Hartford	1,808	n/a
28	Danbury Hospital nuvancehealth.org A not-for-profit community hospital providing convenient access to exceptional care, committed to improving health and well-being through personalized services and wellness programs	Hospitals and Health Care	🇺🇸 Danbury	1,466	n/a
29	Genesee & Wyoming Inc.gwrr.com This company operates 115 freight railroads globally, with 7,300 employees, and provides services to 3,000 customers	Rail Transportation	🇺🇸 Darien	1,295	n/a
30	Connecticut Department of Transportation ct.gov They aim to provide a safe and efficient transportation network to enhance quality of life and economic growth in Connecticut	Government Administration	🇺🇸 Newington	1,248	1895
31	Hospital for Special Care hfsc.org A leading long-term acute care hospital providing specialized care and rehabilitation for adults and children with various medical conditions in Connecticut	Hospitals and Health Care	🇺🇸 New Britain	1,185	1941
32	Lawrence + Memorial Hospital lmhospital.org A not-for-profit hospital providing acute care services to a diverse range of patients in Connecticut and beyond, with specialized medical programs and advanced diagnostic technology	Hospitals and Health Care	🇺🇸 New London	1,175	n/a
33	Saint Mary's Hospital stmh.org Acute care hospital in Greater Waterbury offering cardiac, stroke, pediatric emergency care, surgical services, and robotic surgery Affiliated with Trinity Health	Hospitals and Health Care	🇺🇸 Waterbury	1,145	1909
34	The Hospital of Central Connecticut thocc.org A healthcare network offering comprehensive services including acute care, trauma centers, behavioral health, senior care, and specialized care in various medical fields	Hospitals and Health Care	🇺🇸 New Britain	1,135	2006
35	Griffin Hospital griffinhealth.org A 160-bed acute care community hospital known for patient-centered care, affiliated with Yale School of Medicine, and recognized for industry-leading patient satisfaction	Hospitals and Health Care	🇺🇸 Derby	1,082	1909
36	Bristol Hospital and Health Care Group, Inc.bristolhealth.org Leading healthcare provider in the greater Bristol area since 1921, offering a wide range of services including emergency care, surgical center, maternity unit, ICU, and more	Hospitals and Health Care	🇺🇸 Bristol	1,066	1921
37	The William W. Backus Hospital backushospital.org A leading healthcare provider in eastern Connecticut, offering a wide range of services through an integrated health system within Hartford HealthCare	Hospitals and Health Care	🇺🇸 Norwich	1,011	1893
38	Liberty Bank - CT liberty-bank.com Provides consumer and commercial banking, mortgages, loans, insurance, investments, and cash management services across Connecticut and Massachusetts.	Banking	🇺🇸 Middletown	949	1825
39	Masonicare masonicare.org Connecticut-based provider of healthcare and retirement living for seniors, offering compassionate care, support, and various services in different settings statewide	Hospitals and Health Care	🇺🇸 Wallingford	909	n/a
40	Yale New Haven Hospital - Saint Raphael Campus ynhh.org A hospital campus in New Haven, CT with 1,541 beds, comprised of children's, cancer, and psychiatric hospitals, and affiliated with Yale School of Medicine	Hospitals and Health Care	🇺🇸 New Haven	873	1907
41	Waterbury Hospital waterburyhospital.org An award-winning hospital focused on providing exceptional patient care with a compassionate team of doctors, nurses, and staff	Hospitals and Health Care	🇺🇸 Waterbury	838	1890
42	MidState Medical Center midstatemedical.org MidState Medical Center provides high-quality acute-care services including surgery, emergency medicine, oncology, maternal fetal medicine, and specialized care through Hartford HealthCare network	Hospitals and Health Care	🇺🇸 Meriden	819	1998
43	Western Connecticut Health Network (WCHN)nuvancehealth.org A healthcare network providing personalized care through three hospitals, a large medical group, and home care services to local communities	Hospitals and Health Care	🇺🇸 Danbury	794	n/a
44	Sterling National Bank websterbank.com A leading commercial bank offering financial solutions to businesses, individuals, families, and partners through digital and traditional service delivery	Banking	🇺🇸 Stamford	787	n/a
45	Moran Towing Corporation morantug.com This company provides ship docking, marine transportation, LNG activities, and contract towing services with a fleet of tugs and barges in multiple locations	Transportation, Logistics, Supply Chain and Storage	🇺🇸 New Canaan	738	1860
46	Day Kimball Health daykimball.org A premier provider of integrated healthcare services in Northeast Connecticut and nearby areas, offering a comprehensive network of medical care and specialties	Hospitals and Health Care	🇺🇸 Putnam	685	1894
47	GSB mygsb.bank Established in 1875, GSB is a trusted financial institution on the Connecticut Shoreline, offering personalized banking services and opportunities for talented individuals	Banking	🇺🇸 Guilford	667	1875
48	Hartford HealthCare Medical Group hartfordhealthcare.org A large multi-speciality medical group in Connecticut, part of a comprehensive healthcare network offering high-quality care across various specialties and services	Medical Practices	🇺🇸 Hartford	660	n/a
49	Athena Health Care Systems athenahealthcare.com A regional leader providing skilled nursing, assisted living, home health, hospice care, and private duty programs in Southern New England	Hospitals and Health Care	🇺🇸 Farmington	630	1984
50	Wheeler Health wheelerhealth.org This company offers integrated primary and behavioral health, education, and recovery solutions for individuals, families, and communities in Connecticut	Hospitals and Health Care	🇺🇸 Plainville	594	1968
51	Gaylord Specialty Healthcare gaylord.org Nonprofit health system in Connecticut offering inpatient and outpatient rehabilitation services for individuals recovering from illness or injury Committed to quality care and compassion	Hospitals and Health Care	🇺🇸 Wallingford	567	1902
52	Community Health Resources chrhealth.org A leading provider of behavioral health services in Connecticut, offering personalized care for mental illness, addiction, and trauma through community-based programs and expert staff	Mental Health Care	🇺🇸 Windsor	557	1966
53	Talcott Financial Group talcott.com A life insurance and annuity company with a focus on client needs and innovative solutions, backed by a leading global investment firm	Insurance	🇺🇸 Hartford	506	2018
54	Formerly UIL Holdings (now part of Avangrid)avangrid.com A diversified energy and utility company with operations in 25 states, including regulated utilities, electricity generation, and natural gas storage	Utilities	🇺🇸 Orange	382	n/a
55	American Eagle Financial Credit Union americaneagle.org A not-for-profit financial institution offering products and services to help members achieve financial goals with caring, trust, and dependability	Banking	🇺🇸 East Hartford	278	1935
56	Wilton Re wiltonre.com A US life re-insurance company specializing in acquiring in force life insurance and annuities, providing risk capital, and implementing new business strategies	Insurance	🇺🇸 Norwalk	166	n/a
57	Greenskies Clean Focus greenskies.com A leading developer and operator of clean, renewable-energy projects in the United States, offering integrated solar and battery-storage solutions to various customers	Solar Electric Power Generation	🇺🇸 North Haven	113	2009
58	Northwest Community Bank nwcommunitybank.com A community-focused mutual savings bank providing consumer and commercial banking services, supporting local charities, and prioritizing customer relationships for over 150 years	Banking	🇺🇸 Winsted	110	1875
59	Crossbridge Energy crossbridge.dk Global company owning and managing energy infrastructure as it transitions, contributing to the sustainable energy industry on an international scale	Oil and Gas	🇺🇸 Darien	100	2021
60	Starion Energy starionenergy.com A competitive energy supplier providing solutions to residential and business customers in restructured electricity and natural gas markets across 13 states	Oil and Gas	🇺🇸 Middlebury	76	2009
61	Achieve Financial Credit Union Inc.achievefinancialcu.com The company offers personalized financial services and products to simplify everyday banking and help customers reach their future goals	Banking	🇺🇸 Berlin	27	n/a

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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 Connecticut

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