| Item | Obligations |
|---|---|
| Commercial and Institutional Building Construction | $30.3B |
| Ship Building and Repairing | $7.9B |
| Security Guards and Patrol Services | $4.3B |
| Process, Physical Distribution, and Logistics Consulting Services | $3.2B |
| Other Computer Related Services | $2.5B |
| Computer Systems Design Services | $2.5B |
| Engineering Services | $1.8B |
| All Other Travel Arrangement and Reservation Services | $1.2B |
| Other Support Activities for Air Transportation | $1.1B |
| Search, Detection, Navigation, Guidance, Aeronautical, and Nautical System and Instrument Manufacturing | $943M |
Commercial and Institutional Building Construction was Homeland Security's largest contract category, with $30.3B obligated (43.8% of contract spending).