Alternative Fuel Tax

Retail sales for CNG, propane, hydrogen, and other alternative fuels used to operate vehicles are subject to a modified tax based on energy content. CNG is taxed per 120 cubic feet, measured at 14.73 pounds per square inch absolute base pressure. Propane is taxed per gallon, hydrogen is taxed per kilogram, and all other alternative fuels are taxed using the gasoline-gallon equivalency from DOE’s current fuel-properties chart, multiplied by Montana’s gasoline tax rate. Exceptions may apply. Dealers must collect and remit the tax.

(Reference Montana Code Annotated 15-70-711)