To amend the Internal Revenue Code of 1986 to modify the incentives for the production of biodiesel, and for other purposes.

Amends the Internal Revenue Code to revise the income and excise tax credits for biodiesel used as fuel to: (1) allow a $1.00 tax credit for each gallon of biodiesel produced, (2) provide for an increased income tax credit for small biodiesel producers, (3) revise the definitions of "biodiesel" and "small biodiesel producer," (4) treat renewable diesel in the same manner as biodiesel for income tax purposes, and (5) treat biodiesel as a taxable fuel for excise tax purposes. Extends the biodiesel income and excise tax credits through December 31, 2014.

Requires the Comptroller General to report to Congress by June 30, 2015, on tax preferences for the production of fuel and electricity from renewables and fossil fuels and their benefits and costs to the environment and the economy.