Top Private Companies | Rank | Company | Revenue | Employees | Industry | | 1 | Mars Inc. | 17,500,000 | 30,000 | Manufacturing | | 2 | Geico Corp. | 6,670,000 | 20,000 | Financial services | | 3 | Mid-Atlantic Cars (Brown Automotive Group) | 3,000,000 | 3,500 | Retail | | 4 | Allegis Group | 2,610,000 | 4,600 | Consulting/professional services | | 5 | Clark Enterprises Inc. | 2,600,000 | 4,500 | Real estate | | 6 | Booz Allen Hamilton Inc. | 2,200,000 | 12,250 | Consulting/professional services | | 7 | MedStar Health | 2,110,000 | 22,000 | Health care | | 8 | Goodwill Industries Inc. | 1,940,050 | 144,496 | Retail | | 9 | Discovery Communications | 1,710,000 | 5,000 | Media | | 10 | Ritz Camera Centers Inc. | 1,340,000 | 12,000 | Retail | | 11 | Inova Health System | 1,279,879 | 13,000 | Health care | | 12 | B.F. Saul Real Estate Investment Trust | 1,013,446 | - | Real estate | | 13 | Rosenthal Automotive | 867,954 | 1,500 | Retail | | 14 | Feld Entertainment | 780,000 | 1,550 | Hospitality/travel | | 15 | Bureau of National Affairs Inc. | 309,790 | 1,999 | Media | | 16 | Allbritton Communications Co. | 196,169 | 943 | Media | | 17 | Sunburst Hospitality Corp. | 125,000 | 2,000 | Hospitality/travel | |