| Our Lady of Good Counsel High School | Other Services (except Public Administration) | $3,318,676 | $3,356,195 | 398 | N/A |  Research |
| O'connell & Lawrence, Inc. | Professional, Scientific, and Technical Services | $1,483,085 | $1,493,378 | 99 | $12.2M | Research |
| O'connell & Lawrence Inc. | Professional, Scientific, and Technical Services | $1,483,085 | $1,497,266 | 94 | $11.6M | Research |
| Luis Group Eight, LLC | Accommodation and Food Services | $1,415,699 | $1,431,136 | 266 | $47.2M | Research |
| Rockhammer Talent Solutions, LLC | Administrative and Support and Waste Management | $1,101,700 | $1,114,370 | 42 | $6.6M | Research |
| St Peters Church | Other Services (except Public Administration) | $862,766 | $871,559 | 96 | N/A | Research |
| R&r Contracting Utilities Inc. | Construction | $787,996 | $793,381 | 56 | $17.4M | Research |
| R&r Contracting Utilities, Inc. | Construction | $777,800 | $788,408 | 60 | $18.6M | Research |
| Rockhammer Talent Solutions LLC | Professional, Scientific, and Technical Services | $766,394 | $375,155 | 37 | $11.8M | Research |
| Olney Theatre Corporation | Arts, Entertainment, and Recreation | $738,877 | $744,930 | 40 | N/A | Research |
| Olney Theatre Corporation | Arts, Entertainment, and Recreation | $738,877 | $746,512 | 40 | N/A | Research |
| Winter Growth Inc. | Health Care and Social Assistance | $515,100 | $519,376 | 56 | N/A | Research |
| Winter Growth, Inc. | Health Care and Social Assistance | $515,100 | $519,080 | 75 | N/A | Research |
| L Enfant Corp | Educational Services | $504,700 | $508,331 | 65 | $7.8M | Research |
| H.w. Fletcher INC | Retail Trade | $481,100 | $484,553 | 35 | $11.7M | Research |
| St. Johns Episcopal Church and School | Educational Services | $473,000 | $478,093 | 49 | $5.9M | Research |
| L Enfant Corp | Educational Services | $467,220 | $470,893 | 35 | <$5M | Research |
| Rivermatrix Technologies, Inc. | Professional, Scientific, and Technical Services | $466,797 | $472,168 | 17 | <$5M | Research |
| Grillmarx LLC | Accommodation and Food Services | $436,535 | $440,733 | 65 | $11.5M | Research |
| Holbert Apple Associates INC | Professional, Scientific, and Technical Services | $420,600 | $424,748 | 20 | <$5M | Research |
| Washington Christian School Society Inc. | Educational Services | $406,491 | $409,676 | 42 | $5.0M | Research |
| Washington Christian School Society, Inc. | Educational Services | $406,491 | $410,879 | 42 | $5.0M | Research |
| Mosaddegh Physical Therapy, Inc. | Wholesale Trade | $394,790 | $399,582 | 27 | $8.3M | Research |
| Mosaddegh Physical Therapy, Inc. | Other Services (except Public Administration) | $374,007 | $375,804 | 41 | $7.8M | Research |
| Affiliated Oral and Maxillofacial Surgeons of Maryland | Health Care and Social Assistance | $350,000 | $354,404 | 22 | $5.1M | Research |