Executive Branch Conflict of Interest Act This bill expands and establishes new prohibitions related to conflicts of interest involving certain federal government employees. Specifically, the bill prohibits a federal government employee from accepting a bonus from a former private sector employer for entering government service. The bill prohibits certain senior officials from using their position to participate in matters wherein a former employer or client has a financial interest, and it establishes penalties for an official who violates this prohibition. The bill also increases lobbying restrictions to two years for certain senior officials. In addition, the bill expands prohibitions that prevent certain former officials who were responsible for specified government contracts from receiving compensation from a participating contractor, contractor's affiliate, or subcontractor. The bill also prohibits a procurement officer in the federal government from working for a company that received a contract overseen by the procurement officer during the officer's last two years in government service.