Mass Transit Intelligence Prioritization Act - Amends the Homeland Security Act of 2002 to direct the Secretary of Homeland Security (DHS) to make it a priority to assign DHS officers and intelligence analysts, including from the Transportation Security Administration (TSA), to participating state and urban area fusion centers located in high-risk jurisdictions with mass transit systems to enhance security of such systems by assisting law enforcement authorities in identifying, investigating, and otherwise interdicting persons, weapons, and contraband that pose a threat to homeland security.

Makes it a primary responsibility of such officers and analysts to create mass transit intelligence products that: (1) assist law enforcement agencies in deploying their resources most efficiently to help detect and interdict terrorists, weapons of mass destruction, and contraband at U.S. mass transit systems; (2) promote more consistent and timely dissemination of mass transit security-relevant information among jurisdictions with such systems; and (3) enhance DHS's situational awareness with respect to the threat of terrorist acts at or involving U.S. mass transit systems.