- Internal Revenue Service
- International Association for Exhibition Management IAEM)
- International Association for Organ Donation
- International Association of Chief of Police
- International Association of Convention and Visitor Bureaus
- International Association of Convention and Visitors Bureau
- International Association of Lighting Designers
- International Association of Refrigerated Warehouses
- International Biometric Association
- International Black Women's Congress
- International Code Council
- International Dairy Foods Association
- International Destinations, Inc.
- International Erosion Control Association
- International Freight Forwarders Customs Brokers Association of New Orleans
- International Hearing Society
- International History Week Awards Committee
- International Imaging Materials, Inc
- International Institute of Wisconsin Inc.
- International Life Sciences Institute
- International Lighthouse Group, Inc.
- International Loss Preventions, Inc.
- International Magnesium Association
- International Managed Care Service of Puerto Rico, Inc.
- International Managed Care Services
- International Marketing Managers
- International Mutual Assistance Association
- International Palms Hotel International Drive, Orlando
- International Paper
- International Paper, Inc.
- International Police Mountain Bike Association
- International Postal Systems
- International Sign Association
- International Society on Hypertension in Blacks
- International Steel Group, Inc.
- International Technology Education Association
- International Trade Council
- International Travel Services, Inc.
- International Truck and Engine Corp
- International Truck and Engine-Navistar
- International Union of Police Associations
- Internet Destination Sales System
- Interstate Hotels and Resorts
- Intex Corporation
- Intra Luminal
- INTREGRIS Baptist Medical Center
- Intuitive Business Concepts
- Invacare Continuing Care Group
- Invaluable Solutions, LLC
- Inverness Hotel and Golf Club, Denver