The tax on gasoline sold in Vermont fluctuates every three months based on the average retail price during the prior three months.
This because of two different taxes: a Motor Fuel Transportation Infrastructure Assessment (MFTIA) and a Motor Fuel Tax Assessment (MFTA).
The MFTIA is at least 3.96 cents per gallon (cts/gal). While that's the floor, the MFTIA is set at 2% of the tax-adjusted retail price sold the prior quarter. As the cost of a gallon of gasoline goes up, so does the MFTIA.
The other tax, the MFTA, is at least 13.4 cts/gal. It also increases based on the price at the pump, but it has a ceiling of 18 cts/gal.
The MFTIAF was signed into law in 2009 and is found in Title 23, Chapter 28.