Homeland Threat Assessment Act This bill requires the Department of Homeland Security's Office of Intelligence and Analysis to assess the terrorist threat to the homeland for each of the next five fiscal years. Each assessment shall include: empirical data assessing terrorist activities and incidents over time in the United States; an evaluation of current and future terrorist tactics; an assessment of criminal activity suspected of financing terrorist activity; detailed information on all individuals denied entry to or removed from the United States as a result of material support provided to a foreign terrorist organization; the efficacy and spread of foreign terrorist organization propaganda, messaging, or recruitment; an assessment of threats, including cyber threats, to the homeland, including to critical infrastructure and federal civilian networks; an assessment of terrorism and criminal threats posed by individuals and organized groups seeking to unlawfully enter the United States; and an assessment of threats to the transportation sector.