A fundamental tax planning strategy is to accelerate deductible expenses into the current year. This typically will defer (and in some cases permanently reduce) your taxes. But there are exceptions. One is if the additional deductions this year trigger the alternative minimum tax (AMT).
Investment interest — interest on debt used to buy assets held for investment, such as margin debt used to buy securities — generally is deductible for both regular tax and alternative minimum tax purposes. But special rules apply that can make this itemized deduction less beneficial than you might think.