Recognizing that greenhouse gas emission reduction is but one policy objective that biofuels may potentially serve, this brief evaluates current and potential biofuel policies and explores how effective these policies are in achieving emission reductions. While other reports provide comprehensive catalogs of the policy mechanisms affecting biofuels, the focus of this brief is on the potential greenhouse gas implications of individual policies. To provide context to the discussion, an overview of the current policy environment is included below. This is followed by summaries of multiple biofule policy options, each with a focus on potential greenhouse gas implications. The brief concludes with a series of policy design considerations.