| Item | Obligations |
|---|---|
| Commercial and Institutional Building Construction | $28.6B |
| Ship Building and Repairing | $7.7B |
| Security Guards and Patrol Services | $3.6B |
| Process, Physical Distribution, and Logistics Consulting Services | $2.6B |
| Computer Systems Design Services | $1.9B |
| Other Computer Related Services | $1.7B |
| Engineering Services | $1.2B |
| All Other Travel Arrangement and Reservation Services | $1B |
| Search, Detection, Navigation, Guidance, Aeronautical, and Nautical System and Instrument Manufacturing | $840M |
| Nonscheduled Chartered Passenger Air Transportation | $736M |
Commercial and Institutional Building Construction was Homeland Security's largest contract category, with $28.6B obligated (48.0% of contract spending).