The U.S. Department of the Treasury and Internal Revenue Service (IRS) have released guidance on the Sustainable Aviation Fuel (SAF) Credit established by the Inflation Reduction Act (IRA). The guidance identifies eligible models for measuring lifecycle greenhouse gas emissions reduction, which will be used to qualify for and calculate the tax credit. The U.S. Department of Energy announced plans to develop a modified version of its Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model that would be eligible, as well.