A project is the lowest published level of the RDT&E budget. Program elements are the funding lines Congress votes on; projects are the named efforts inside them, each with its own description, accomplishments, and planned work in the justification books. This is where a budget line stops being an abstraction and names an actual piece of engineering.
There are 306 project pages here, extracted from public R-2 exhibits. They range from submarine sonar improvement to DARPA technology development to mixed-technology integration.
How to use this layer
Start from the program element if you know the funding line, or search directly if you know the project name or number. Project numbers are not unique across the department: the same number appears under different program elements, so always read a project in the context of its parent PE.
The useful questions this layer answers: what is the money actually building, has the described work changed year over year, and does the accomplishment narrative match the funding curve.
Where projects sit
Appropriation → budget activity → program element → project. See DoD_Budget_Hierarchy for the full chain and appropriations for the accounts above.
Program-element-level detail, contractor mapping, and cross-year comparison are part of the client reference library.
Searching
Use the search box for a project number (0219), a system name (sonar, hypersonic), or an agency. The budget search queries the underlying budget engine directly across program elements, procurement line items, and O&M rows.