Windfall Profit Tax and Deficit Reduction Act of 1990

Windfall Profit Tax and Deficit Reduction Act of 1990 - Amends the Internal Revenue Code to reinstate the windfall profit tax on domestic crude oil. Revises the inflation adjustment and declares the base price to be the average price per barrel of taxable crude oil during the four-month period ending on July 31, 1990, as determined by the Secretary of the Treasury. Repeals the phaseout of the tax, thus making the tax permanent law. Limits the category of newly discovered oil to oil from newly drilled wells.

Declares the term taxable crude oil to include any futures contract on taxable crude oil and provides for its tax treatment.

Establishes the Low Income Energy Support Trust Fund to fund the grant program under the Low-Income Home Energy Assistance Act of 1981 and the weatherization program under the Energy Conservation in Existing Buildings Act of 1976. Transfers to such Fund 50 percent of the taxes received from the windfall profit tax on domestic crude oil.

Requires the use of the first-in, first-out method of accounting for crude oil inventorying.