- Biomerix
- Board of Elections
- Bon Secours Health System Inc.
- Bourne and Associates P.A.
- Brede Exposition Services
- Bregman, Berbert, Schwartz and Gilday
- BridgeStreet Baltimore
- Calvert County Dept. of Economics Development
- CalvertHealth Medical Center
- Canton Group
- Capital Financial Group Inc.
- Career Communications Group
- CareFirst
- Carousel Resort Hotel and Condos
- Carroll County
- Carroll County Board of Commissioners
- Carroll Hospital - A LifeBridge Healthcare Center
- Carroll Lutheran Village
- Catholic Charities, Medical Care Community Partnership
- CBM
- CCRC Actuaries, LLC
- CCS Fund Raising
- Center for Sex Offender Management
- Centrol, Inc.
- Cetrom
- CGS Creative
- Chambers
- Chesapeake Bus and Equipment Company
- Choice Hotels International
- CIP Print Media
- Clemons and Associates, Inc.
- Clever Consultants, LLC
- Click Shot Inc.
- CM Beavan Associates
- Coconut Malorie Hotel
- Cogs Meeting Solutions, LLC
- CommPartners
- Comprehensive Housing Assistance Inc.
- Conference and Logistics Consultants, Inc.
- Conference Direct
- Courtyard by Marriott Baltimore Downtown-Inner Harbor
- Crosby Marketing
- Crossroads Research
- CRSA Inc.
- CSD
- DCS
- DeLCor Technology Solutions
- Department of Health and Human Services, NIH-NCI
- Design Data Systems, Inc.
- Design Purchase Link