# Top 39 critical infrastructure operators in New Hampshire

Tamtam tracks 39 critical infrastructure operators headquartered in New Hampshire. This list ranks all of them by number of employees on LinkedIn, led by Dartmouth Hitchcock Medical Center and Clinics, Transavia and Cordaan. Their median headcount is 508. Half of them were founded in 1918 or later. The most common headquarters are Manchester (6), Portsmouth (5) and Lebanon (4).

These are critical infrastructure operators, predominantly large healthcare systems, in New Hampshire. Dartmouth Hitchcock Medical Center and Clinics is an integrated health system. Concord Hospital Health System is a nonprofit health system. Elliot Health System provides comprehensive healthcare services. Service Credit Union is a member-owned financial cooperative.

The data shows a strong concentration in the healthcare sector, with many hospitals and health systems founded in the late 19th century, such as Elliot Health System (1890), Southern New Hampshire Health (1891), and Cheshire Medical Center (1892).

🇺🇸 New Hampshire · 39 companies · Updated Nov 14, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Dartmouth Hitchcock Medical Center and Clinics](https://www.tamtam.ai/c/dartmouth-hitchcock-medical-center-and-clinics) (dartmouth-hitchcock.org)<br>Integrated health system providing advanced medical care, cancer treatment, pediatric services, and extensive ambulatory clinics across New Hampshire and Vermont. | Hospitals and Health Care | 🇺🇸 Lebanon | 7,814 |  |
| 2 | [Transavia](https://www.tamtam.ai/c/transavia) (transavia.com)<br>An airline with 50 years of experience flying passengers to over 160 destinations, offering easy booking, various fare options, and dedicated services for business travelers | Airlines and Aviation | 🇺🇸 Schiphol | 5,275 | 1965 |
| 3 | [Cordaan](https://www.tamtam.ai/c/cordaan) (werkenbijcordaan.nl)<br>The company provides care and support for individuals of all ages and backgrounds, focusing on promoting self-reliance and respecting individual choices and differences | Hospitals and Health Care | 🇺🇸 Amsterdam | 3,647 | 1683 |
| 4 | [Concord Hospital Health System](https://www.tamtam.ai/c/concord-hospital-health-system) (concordhospital.org)<br>Nonprofit health system in New Hampshire with multiple campuses, providing integrated healthcare services to meet community needs and improve lives | Hospitals and Health Care | 🇺🇸 Concord | 2,909 |  |
| 5 | [Elliot Health System](https://www.tamtam.ai/c/elliot-health-system) (elliothospital.org)<br>Comprehensive healthcare services focused on improving community wellness, patient healing, and compassionate care throughout New Hampshire. | Hospitals and Health Care | 🇺🇸 Manchester | 2,666 | 1890 |
| 6 | [GGZ Noord-Holland-Noord](https://www.tamtam.ai/c/ggz-noord-holland-noord) (ggz-nhn.nl)<br>A mental health organization in Noord-Holland providing innovative, patient-centered care by competent professionals using the latest scientific knowledge and personal commitment | Mental Health Care | 🇺🇸 Heerhugowaard | 1,743 | 1997 |
| 7 | [Catholic Medical Center](https://www.tamtam.ai/c/catholic-medical-center) (catholicmc.com)<br>A regional healthcare organization providing high quality and innovative healthcare services in a compassionate environment, with roots dating back to 1892 | Hospitals and Health Care | 🇺🇸 Manchester | 1,597 |  |
| 8 | [Dartmouth Health](https://www.tamtam.ai/c/dartmouth-health) (dartmouth-health.org)<br>Leading academic health system in New Hampshire, serving northern New England with top-ranked hospital, comprehensive cancer center, children's hospital, clinics, and research initiatives | Hospitals and Health Care | 🇺🇸 Lebanon | 1,481 |  |
| 9 | [Southern New Hampshire Health](https://www.tamtam.ai/c/southern-new-hampshire-health) (snhhealth.org)<br>Leading healthcare network in northern MA and southern NH with primary, emergency, specialty, pediatric, and maternal care services Affiliated with Massachusetts General Hospital | Hospitals and Health Care | 🇺🇸 Nashua | 1,388 | 1891 |
| 10 | [Exeter Hospital](https://www.tamtam.ai/c/exeter-hospital) (exeterhospital.org)<br>A tax-exempt community-based hospital affiliated with Exeter Health Resources, focused on innovative, quality healthcare services across various medical specialties | Hospitals and Health Care | 🇺🇸 Exeter | 1,081 |  |
| 11 | [Valley Regional Hospital](https://www.tamtam.ai/c/valley-regional-hospital) (vrh.org)<br>Valley Regional Hospital provides modern healthcare services including private patient rooms, emergency care, cancer care, primary care, rehabilitation, imaging, and more since 1893 | Hospitals and Health Care | 🇺🇸 Claremont | 1,022 | 1893 |
| 12 | [Service Credit Union](https://www.tamtam.ai/c/service-credit-union) (servicecu.org)<br>Member-owned financial cooperative offering banking services across multiple states and Germany, focusing on member well-being and community support. | Banking | 🇺🇸 Portsmouth | 925 | 1957 |
| 13 | [Cheshire Medical Center](https://www.tamtam.ai/c/cheshire-medical-center) (cheshiremed.org)<br>A non-profit community hospital in New Hampshire's Monadnock Region providing a wide range of specialties, comprehensive care, and a supportive team environment | Hospitals and Health Care | 🇺🇸 Keene | 888 | 1892 |
| 14 | [Portsmouth Regional Hospital - New Hampshire](https://www.tamtam.ai/c/portsmouth-regional-hospital-new-hampshire) (wwwprod104-portsmouthhospital-sitecore-cloud.dpxmedcity.net)<br>A 234-bed acute care hospital in Portsmouth, NH, offering comprehensive cardiovascular, neurosurgical, and stroke care as part of HCA Healthcare's Capital Division | Hospitals and Health Care | 🇺🇸 Portsmouth | 820 |  |
| 15 | [KAS BANK](https://www.tamtam.ai/c/kas-bank) (caceis.com)<br>Specialized asset servicing banking group providing a comprehensive range of services across Europe, North America, and Asia to financial institutions and corporate clients | Banking | 🇺🇸 Amsterdam | 816 | 1806 |
| 16 | [Northeast Rehabilitation Hospital Network](https://www.tamtam.ai/c/northeast-rehabilitation-hospital-network) (northeastrehab.com)<br>Provide inpatient and outpatient rehabilitation care for injuries and illnesses in New Hampshire and Massachusetts Services include therapy, home care, sports medicine, and pain management clinics | Hospitals and Health Care | 🇺🇸 Salem | 658 | 1984 |
| 17 | [ConvenientMD](https://www.tamtam.ai/c/convenientmd) (convenientmd.com)<br>A leading urgent care provider in New England focused on making healthcare more convenient, with plans for expanding primary care services | Hospitals and Health Care | 🇺🇸 Portsmouth | 648 | 2012 |
| 18 | [St. Joseph Hospital (Nashua, NH)](https://www.tamtam.ai/c/st-joseph-hospital-nashua-nh) (stjosephhospital.com)<br>A leading-edge acute care community hospital providing innovative medical care, leading-edge technology, and specialized treatment services with a dedicated physician network | Hospitals and Health Care | 🇺🇸 Nashua | 564 | 1908 |
| 19 | [Cottage Hospital](https://www.tamtam.ai/c/cottage-hospital) (linktr.ee)<br>A critical access hospital in Woodsville, NH with 25 beds, 250 employees, 37 medical staff, and 35 volunteers serving the Upper Connecticut River Valley | Hospitals and Health Care | 🇺🇸 Woodsville | 523 | 1903 |
| 20 | [Sprague Operating Resources LLC](https://www.tamtam.ai/c/sprague-operating-resources-llc) (spragueenergy.com)<br>A leading independent supplier of energy and materials handling services in the Northeast, offering products like home heating oil, diesel, gasoline, and natural gas | Oil and Gas | 🇺🇸 Portsmouth | 508 | 1870 |
| 21 | [FirstLight Fiber](https://www.tamtam.ai/c/firstlight-fiber) (firstlight.net)<br>A fiber-based company in the Northeast and Mid-Atlantic providing high-capacity, low-latency fiber optic network, data centers, managed services, and cloud solutions to enterprise and carrier customers | Telecommunications | 🇺🇸 Portsmouth | 470 | 1999 |
| 22 | [New Hampshire Mutual Bancorp](https://www.tamtam.ai/c/new-hampshire-mutual-bancorp) (nhmutual.com)<br>A shared services organization providing operational support for multiple mutual savings banks and a financial advisory and trust company in northern New England | Banking | 🇺🇸 Concord | 460 | 2013 |
| 23 | [Monadnock Community Hospital](https://www.tamtam.ai/c/monadnock-community-hospital) (monadnockcommunityhospital.com)<br>A 25-bed rural community hospital providing quality care in a modern facility nestled near Mount Monadnock, prioritizing patient privacy and tranquility | Hospitals and Health Care | 🇺🇸 Peterborough | 459 | 1923 |
| 24 | [New London Hospital](https://www.tamtam.ai/c/new-london-hospital) (newlondonhospital.org)<br>A rural community hospital providing high-quality healthcare services to the Lake Sunapee region in central New Hampshire, with a focus on patient-centered care and community collaboration | Hospitals and Health Care | 🇺🇸 New London | 448 | 1918 |
| 25 | [Unitil](https://www.tamtam.ai/c/unitil) (unitil.com)<br>A public utility company delivering natural gas and electricity in New England with a focus on safety, reliability, and community involvement | Utilities | 🇺🇸 Hampton | 437 | 1984 |
| 26 | [Frisbie Memorial Hospital](https://www.tamtam.ai/c/frisbie-memorial-hospital) (wwwprod104-frisbiehospital-sitecore-cloud.dpxmedcity.net)<br>Dedicated to providing safe, effective, and patient-centered healthcare services to the community, while collaborating with other providers to enhance overall health | Hospitals and Health Care | 🇺🇸 Rochester | 425 |  |
| 27 | [Parkland Medical Center](https://www.tamtam.ai/c/parkland-medical-center) (parklandmedicalcenter.com)<br>An acute care hospital providing high-quality healthcare services including emergency care, behavioral health, cardiology, oncology, orthopedics, women's and children's services, and surgical care | Hospitals and Health Care | 🇺🇸 Derry | 399 |  |
| 28 | [Mascoma Bank](https://www.tamtam.ai/c/mascoma-bank) (mascoma.bank)<br>Mutually owned bank focused on community reinvestment, prioritizing customers with local decision-making and a wide range of financial services | Banking | 🇺🇸 Lebanon | 370 | 1899 |
| 29 | [City of Manchester, NH](https://www.tamtam.ai/c/city-of-manchester-nh) (manchesternh.gov)<br>A public sector organization in Manchester with a focus on upholding core values like service, pride, integrity, respect, initiative, and teamwork | Government Administration | 🇺🇸 Manchester | 360 | 1846 |
| 30 | [Alice Peck Day Memorial Hospital](https://www.tamtam.ai/c/alice-peck-day-memorial-hospital) (alicepeckday.org)<br>A healthcare organization within the Dartmouth Health system, providing personalized care to over 80,000 patients annually with a focus on diverse and inclusive services | Hospitals and Health Care | 🇺🇸 Lebanon | 329 | 1932 |
| 31 | [New Hampshire Department of Transportation (NHDOT)](https://www.tamtam.ai/c/new-hampshire-department-of-transportation-nhdot) (dot.nh.gov)<br>A transportation department in New Hampshire ensuring safe, efficient travel options and protecting the environment Offers career opportunities and traffic updates online | Truck Transportation | 🇺🇸 Concord | 317 |  |
| 32 | [Lighthouse Credit Union](https://www.tamtam.ai/c/lighthouse-credit-union) (lighthousecu.org)<br>A purpose-driven credit union investing in communities through financial services, competitive benefits, and opportunities to make a positive impact | Financial Services | 🇺🇸 Dover | 317 | 1936 |
| 33 | [Mental Health Center of Greater Manchester](https://www.tamtam.ai/c/mental-health-center-of-greater-manchester) (mhcgm.org)<br>A leading community mental health center in New Hampshire offering behavioral health services for all ages, with a focus on short-term counseling | Mental Health Care | 🇺🇸 Manchester | 315 |  |
| 34 | [Huggins Hospital](https://www.tamtam.ai/c/huggins-hospital) (hugginshospital.org)<br>A non-profit community hospital in Wolfeboro, NH offering primary, secondary, and specialty health care services to residents and visitors | Hospitals and Health Care | 🇺🇸 Wolfeboro | 295 |  |
| 35 | [Littleton Regional Healthcare](https://www.tamtam.ai/c/littleton-regional-healthcare) (littletonhealthcare.org)<br>Non-profit Critical Access Hospital in New Hampshire's White Mountains, offering primary and specialty healthcare to the North Country of New Hampshire and Northeast Kingdom of Vermont | Hospitals and Health Care | 🇺🇸 Littleton | 264 | 1907 |
| 36 | [PSNH, now Eversource Energy](https://www.tamtam.ai/c/psnh-now-eversource-energy) (eversource.com)<br>A united energy company serving New England, focused on delivering reliable energy and superior customer service Bringing communities together through energy | Utilities | 🇺🇸 Manchester | 167 |  |
| 37 | [New Hampshire Electric Cooperative, Inc.](https://www.tamtam.ai/c/new-hampshire-electric-cooperative-inc) (nhec.com)<br>A member-owned electric distributor serving 84,000 members in 115 towns in New Hampshire, with over 5,500 miles of energized line | Utilities | 🇺🇸 Plymouth | 126 | 1939 |
| 38 | [Patriot Hydro LLC](https://www.tamtam.ai/c/patriot-hydro-llc) (patriothydro.com)<br>The company provides local, reliable, and renewable clean energy production while focusing on safety, compliance, and high performance of generating facilities | Renewable Energy Power Generation | 🇺🇸 Manchester | 27 |  |
| 39 | [NextEra Energy Seabrook, LLC](https://www.tamtam.ai/c/nextera-energy-seabrook-llc) (nexteraenergyresources.com)<br>This company based in Seabrook, NH delivers clean energy solutions in North America, developing, constructing, and operating power projects while promoting environmental stewardship and community care | Oil and Gas | 🇺🇸 Seabrook | 25 |  |

## 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 14, 2026.

## More company lists in New Hampshire

- [The largest companies in New Hampshire](https://www.tamtam.ai/l/largest-companies-new-hampshire) (448)
- [Manufacturers in New Hampshire](https://www.tamtam.ai/l/manufacturers-new-hampshire) (62)
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- [Companies with in-house R&D in New Hampshire](https://www.tamtam.ai/l/r-and-d-companies-new-hampshire) (50)
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- [Hospitals and Health Care companies in New Hampshire](https://www.tamtam.ai/l/hospitals-and-health-care-companies-new-hampshire) (36)
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- [IT Services and IT Consulting companies in New Hampshire](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-new-hampshire) (25)

## The same list elsewhere in United States

- [Critical infrastructure operators in the United States](https://www.tamtam.ai/l/critical-infrastructure-operators-united-states) (5,801)
- [Critical infrastructure operators in Texas](https://www.tamtam.ai/l/critical-infrastructure-operators-texas) (579)
- [Critical infrastructure operators in California](https://www.tamtam.ai/l/critical-infrastructure-operators-california) (483)
- [Critical infrastructure operators in New York State](https://www.tamtam.ai/l/critical-infrastructure-operators-new-york-state) (379)
- [Critical infrastructure operators in Florida](https://www.tamtam.ai/l/critical-infrastructure-operators-florida) (321)
- [Critical infrastructure operators in Illinois](https://www.tamtam.ai/l/critical-infrastructure-operators-illinois) (241)
- [Critical infrastructure operators in Pennsylvania](https://www.tamtam.ai/l/critical-infrastructure-operators-pennsylvania) (225)
- [Critical infrastructure operators in Alabama](https://www.tamtam.ai/l/critical-infrastructure-operators-alabama) (186)
- [Critical infrastructure operators in North Carolina](https://www.tamtam.ai/l/critical-infrastructure-operators-north-carolina) (171)
- [Critical infrastructure operators in Massachusetts](https://www.tamtam.ai/l/critical-infrastructure-operators-massachusetts) (165)
- [Critical infrastructure operators in Ohio](https://www.tamtam.ai/l/critical-infrastructure-operators-ohio) (153)
- [Critical infrastructure operators in Michigan](https://www.tamtam.ai/l/critical-infrastructure-operators-michigan) (150)
- [Critical infrastructure operators in Washington State](https://www.tamtam.ai/l/critical-infrastructure-operators-washington-state) (149)
- [Critical infrastructure operators in Colorado](https://www.tamtam.ai/l/critical-infrastructure-operators-colorado) (137)
- [Critical infrastructure operators in Tennessee](https://www.tamtam.ai/l/critical-infrastructure-operators-tennessee) (132)
- [Critical infrastructure operators in Virginia](https://www.tamtam.ai/l/critical-infrastructure-operators-virginia) (131)
- [Critical infrastructure operators in New Jersey](https://www.tamtam.ai/l/critical-infrastructure-operators-new-jersey) (130)
- [Critical infrastructure operators in Indiana](https://www.tamtam.ai/l/critical-infrastructure-operators-indiana) (129)
- [Critical infrastructure operators in Georgia](https://www.tamtam.ai/l/critical-infrastructure-operators-georgia) (126)
- [Critical infrastructure operators in Missouri](https://www.tamtam.ai/l/critical-infrastructure-operators-missouri) (120)
- [Critical infrastructure operators in Minnesota](https://www.tamtam.ai/l/critical-infrastructure-operators-minnesota) (115)
- [Critical infrastructure operators in Wisconsin](https://www.tamtam.ai/l/critical-infrastructure-operators-wisconsin) (115)
- [Critical infrastructure operators in Houston](https://www.tamtam.ai/l/critical-infrastructure-operators-houston) (161)
- [Critical infrastructure operators in New York](https://www.tamtam.ai/l/critical-infrastructure-operators-new-york) (139)

## The same list elsewhere

- [Critical infrastructure operators in the world](https://www.tamtam.ai/l/critical-infrastructure-operators-in-the-world) (23,311)
- [Critical infrastructure operators in North America](https://www.tamtam.ai/l/critical-infrastructure-operators-in-north-america) (6,768)

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Source: https://www.tamtam.ai/l/critical-infrastructure-operators-new-hampshire