To require the Administrator of the Environmental Protection Agency to use the commercially available volume of cellulosic biofuel in setting requirements for the renewable fuel program under the Clean Air Act, and for other purposes.

Amends the Clean Air Act, with respect to reductions in requirements to use cellulosic biofuel under the renewable fuel program, to remove the requirement that the Administrator of the Environmental Protection Agency (EPA) determine volumes of transportation fuel based upon estimates of projected sales provided by the Energy Information Administration.

Revises cellulosic biofuel use requirements to require the Administrator to reduce the applicable volume of renewable fuel and advanced biofuels requirement by the same or a lesser volume of the cellulosic biofuel requirements of the renewable fuel program. Limits, for such purposes, the projected volume of cellulosic biofuel production for a calendar year to not more than 5% or 1 million gallons (whichever is greater) more than the total volume of cellulosic biofuel that was commercially available for the most recent calendar year for which such volume is known.