| 1 | LOCKHEED MARTIN CORP | $556,408,619 | 1 | $556,408,619 | Jun 30, 2016 | Department of Defense |
| 2 | MATHEMATICA INC. | $367,605,441 | 22 | $16,709,338 | Sep 08, 2026 | Department of Health and … |
| 3 | RESEARCH TRIANGLE INSTITUTE | $293,366,384 | 9 | $32,596,265 | Mar 17, 2025 | Department of Health and … |
| 4 | NATIONAL OPINION RESEARCH CENTER | $237,792,599 | 11 | $21,617,509 | Jun 29, 2026 | Department of Health and … |
| 5 | THE LEWIN GROUP, INC. | $198,643,412 | 12 | $16,553,618 | Apr 24, 2026 | Department of Health and … |
| 6 | AMERICAN INSTITUTES FOR RESEARCH IN THE BEH… | $180,098,646 | 14 | $12,864,189 | Apr 20, 2026 | Department of Health and … |
| 7 | WESTAT, INC. | $135,954,851 | 8 | $16,994,356 | Dec 31, 2025 | Department of Education |
| 8 | EDUCATIONAL TESTING SERVICE | $108,998,020 | 4 | $27,249,505 | Dec 20, 2024 | Department of Education |
| 9 | ACUMEN LLC | $62,827,923 | 3 | $20,942,641 | Jun 15, 2023 | Department of Health and … |
| 10 | ABT GLOBAL LLC | $60,118,856 | 6 | $10,019,809 | Apr 20, 2026 | Department of Health and … |
| 11 | SOUTHWEST RESEARCH INSTITUTE | $54,576,386 | 1 | $54,576,386 | Dec 22, 2009 | National Aeronautics and … |
| 12 | RELI GROUP INC | $51,622,253 | 1 | $51,622,253 | Sep 24, 2020 | Department of Health and … |
