| # | Company | Employees |
|---|---|---|
| 1 |
National Institute of Standards and Technology (NIST)nist.gov
An innovative federal agency advancing measurement science, standards, and technology to promote US innovation and industrial competitiveness |
4,946 |
| 2 |
Adventist HealthCareadventisthealthcare.com
Faith-based healthcare organization in Maryland, dedicated to improving physical, mental, and spiritual health through hospitals, rehabilitation centers, home care, and physician networks |
3,422 |
| 3 |
Emergent BioSolutionsemergentbiosolutions.com
This company develops, manufactures, and delivers protections against public health threats to defend people and ensure preparedness |
1,366 |
| 4 |
Nobel Learning PBCnobelnavigators.com
International social-learning community preparing youth with technical and human skills for the 21st century global economy through collaboration, empathy, and cultural exchange |
1,026 |
| 5 |
GXSopentext.com
Global integration services provider connecting 550,000+ companies in electronic transactions, specializing in B2B integration services for retailers, manufacturers, and banks |
1,019 |
| 6 |
Navitas Life Sciencesnavitaslifesciences.com
Global clinical research organization providing technology-driven CRO services, data science, regulatory support, and industry-focused consulting to biopharmaceutical clients worldwide |
1,014 |
| 7 |
Novavaxnovavax.com
Creating accessible next generation vaccines to combat infectious diseases and viral threats, driven by passion for global health and guided by science and technology |
972 |
| 8 |
MedImmuneparkedpage.astrazeneca.com
Global biologics research and development arm focused on discovering, developing, and commercializing small molecule and biologic prescription medicines across various medical areas |
888 |
| 9 |
Glory Days Grillglorydaysgrill.com
A family restaurant chain offering affordable prices, sports-themed atmosphere, award-winning menus, large screen TVs, catering services, and private banquet facilities |
869 |
| 10 |
Shobhamyshobha.com
A leading destination for quality hair removal services, focusing on customer experience, natural ingredients, and ethical treatment of employees |
820 |
| 11 |
OPIS, A Dow Jones Companyopis.com
Provider of accurate price discovery, news, and expert analysis for the fuel supply chain, offering transparent price data and comprehensive pricing solutions |
797 |
| 12 | 402 | |
| 13 |
BOLANDboland.com
A leading provider of sustainable and energy-efficient solutions for commercial, institutional, and industrial buildings in the DC/MD/VA metro area |
394 |
| 14 |
City of Gaithersburggaithersburgmd.gov
Company revitalized Gaithersburg into a thriving city by fostering business, agricultural, residential, and commercial growth while preserving its heritage and promoting cultural and recreational activities |
394 |
| 15 |
Montgomery County Fire and Rescue Servicemontgomerycountymd.gov
A full spectrum life safety agency in Maryland's most populous jurisdiction, operating with a combination system of career and volunteer responders |
366 |
| 16 |
Montgomery County Department of Policemontgomerycountymd.gov
A government administration company located in Rockville, Maryland, specializing in law enforcement services under the Montgomery County Police Department |
340 |
| 17 |
Pratum Companiespratumco.com
Leading East Coast property management company specializing in affordable and mixed-income communities, known for innovation, inclusivity, and fostering a supportive team culture |
333 |
| 18 |
Cardinality-aicardyai.com
A software company specializing in AI and data solutions for government agencies, improving efficiency and outcomes for health and human services programs |
191 |
| 19 |
MLM Home Improvementmlmhi.com
A home improvement company specializing in roofing, siding, doors, and gutters, focused on delivering quality products with exceptional customer service and growth opportunities for employees |
183 |
| 20 |
The Arora Grouparoragroup.com
A nationwide healthcare services provider specializing in staffing for government healthcare contracts for military and federal agencies for over 35 years |
183 |
| 21 |
TW Perrytwperry.com
A leading building materials supplier in the mid-Atlantic region, offering lumber, doors, windows, hardware, decking, paint, power tools, and millwork products with next-day delivery |
183 |
| 22 |
KPL (Part of LGC Clinical Diagnostics)seracare.com
Provider of over 800 high-quality reagents and kits for immunoassays, immunohistochemistry, infectivity assays, and flow cytometry, focusing on sensitivity and specificity optimization |
181 |
| 23 |
ATHENA Consultingathenaconsultingllc.com
A staffing service provider in over 20 states, ATHENA Consulting supports clients with temporary professionals while offering benefits and positive workplace culture |
175 |
| 24 |
Builders Designbuildersdesign.com
The company offers award-winning interior design and merchandising services for various spaces, prioritizing creativity, research, project management, and customer service |
168 |
| 25 |
AUI Fine Foodssecure.auifinefoods.com
Gourmet food provider offering over 1,400 products worldwide, serving various industries with custom solutions, and operating distribution centers nationally and internationally |
163 |
| 26 |
Mercy Health Clinicmercyhealthclinic.org
A nonprofit free clinic in Maryland providing high quality medical care, health education, and pharmaceuticals to low-income uninsured adults since 2000 |
156 |
| 27 |
Computer Packages Inc. - CPIcomputerpackages.com
Provider of innovative IP management solutions, including software, annuity services, and patent data audits, with a focus on excellence and client feedback-driven product development |
154 |
| 28 |
COSO IT - A Big Data & AI Companycosoit.com
Delivers exceptional products, services in Cloud, Big Data, Analytics, and AI. Team of data experts, scientists provides customized, scalable solutions for clients globally. |
150 |
| 29 |
Clinical Research Management, Inc. (ClinicalRM)linkedin.com
Specializing in government and public health solutions, this company offers clinical research and management services Connect with them on LinkedIn |
150 |
| 30 |
k siva reddy corporationnaughtyamerica.com
Lavender Technology, LLC is located in Gaithersburg, Maryland, offering technology services and solutions on Gaithersburg Laytonsville Rd and Young Place in Frederick |
150 |
| 31 |
OSS, Inc.ossjobs.com
IT support company delivering complete services to enhance clients' IT infrastructure, specializing in systems integration, technical architecture, software services, programming, and consulting for commercial and government clients globally |
134 |
| 32 |
RYNO Strategic Solutions (formerly Blue Corona)bluecorona.com
An award-winning digital marketing agency specializing in home services, helping businesses improve their online presence and generate leads and sales |
60 |
| 33 |
Durex Incdurexinc.com
Specializing in top-quality metal stampings, sheet metal fabrications, assemblies, and finished products, providing contract manufacturing services |
47 |
| 34 |
Trigint Solutionstrigintsolutions.com
A global IT company dedicated to empowering business transformation through innovative solutions and technology services |
10 |
| 35 |
Mavin Technologies,Incmavin-tech.com
Provider of software development and consulting services, specializing in custom business solutions, application development, database design, and data warehousing for businesses |
10 |
| 36 |
VivSoftviv-soft.com
A technology company focused on delivering high-quality digital products, transforming markets with disruptive innovations, and helping founders launch efficient solutions |
10 |
| 37 |
AC Remodeling Inc.acremodeling.com
A design and build remodeling company specializing in high-quality renovations for kitchens, bathrooms, basements, and more to bring homeowners' dreams to life |
7 |
| 38 |
Blue Chip Visual Communicationblchip.com
The company focuses on growing brand engagement with environmentally-conscious branded merchandise and sustainable AI-enhanced interactive technologies to captivate and inspire employees and consumers |
7 |
| 39 | 6 | |
| 40 |
Long Design Buildlongdesignbuild.com
Long Design Build offers architectural design and remodeling services for residential, commercial, and industrial projects, creating custom solutions to satisfy clients' needs |
3 |
| 41 |
Young Gen Technologies LLC.younggentech.com
Global IT services provider specializing in staffing and technology consulting, offering solutions for Customer Value Management, Business Optimization, and Data Engineering across various industries |
3 |
Turn this list into pipeline
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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.
The same list elsewhere in United States
- The largest companies in the United States 91,669
- The largest companies in California 12,813
- The largest companies in New York State 10,485
- The largest companies in Texas 8,086
- The largest companies in Florida 4,945
- The largest companies in Illinois 4,175
- The largest companies in Pennsylvania 3,110
- The largest companies in Massachusetts 3,093
- The largest companies in Georgia 2,632
- The largest companies in Ohio 2,618
- The largest companies in New Jersey 2,569
- The largest companies in Virginia 2,503
- The largest companies in Michigan 2,346
- The largest companies in North Carolina 2,174
- The largest companies in Alabama 1,806
- The largest companies in Washington State 1,785
- The largest companies in Colorado 1,774
- The largest companies in Minnesota 1,700
- The largest companies in Maryland 1,527
- The largest companies in Wisconsin 1,482
- The largest companies in New York 6,920
- The largest companies in San Francisco 2,030
- The largest companies in Houston 1,791
- The largest companies in Chicago 1,668