Invest in America First Act of 2013 - Prohibits foreign assistance from being provided to a country with a GDP of $1.5 trillion or more.
Exempts from such prohibition military, security, or humanitarian assistance.
Defines "GDP" as a country's gross domestic product on a purchasing power parity basis divided by the population of the country, as determined by the most recent publication of the Central Intelligence Agency's (CIA) The World Factbook.