Major Drug Trafficking Prosecution Act of 2013 - Requires the Attorney General's prior written approval for a federal prosecution of an offense under the Controlled Substances Act (CSA) or the Controlled Substances Import and Export Act (CSIEA), or for any conspiracy to commit such an offense, where the offense involves the illegal distribution or possession of a controlled substance in an amount less than that specified as a minimum for an offense under CSA or, in the case of any substance containing cocaine or cocaine base, in an amount less than 500 grams.
Modifies CSA and CSIEA to delete specified mandatory minimum terms of imprisonment.