To provide that no entity performing lead system integrator functions in the acquisition of a major system by the Department of Homeland Security may have any direct financial interest in the development or construction of any individual system or element of any system of systems, and for other purposes.

Prohibits any entity performing lead system integrator functions in the acquisition of a major system by the Department of Homeland Security (DHS) from having any direct financial interest in the development or construction of any individual system or element of any system of systems with respect to contracts entered into after May 1, 2007.

Makes exceptions if: (1) the Secretary of Homeland Security certifies that an entity was selected by DHS as a contractor through competitive procedures and DHS took appropriate steps to prevent any organizational conflict of interest in the selection process; (2) an entity was selected by a subcontractor to serve as a lower-tier subcontractor through a process over which the entity exercised no control; or (3) the work to be performed is work necessary to integrate two or more individual systems or elements.

Directs the Secretary, by May 1, 2007, to update DHS's acquisition regulations to: (1) specify the matters regarding lead system integrators set forth in this Act; and (2) include a definition of "lead system integrator" modeled after that used by the Department of Defense (DOD) and a specification of appropriate types of contracts and fee structures for use by integrators in the production, fielding, and sustainment of complex systems.