Margin Interest Expense

Unless you are categorized as a "trader" and can use Schedule C for your business expenses, the answer is "No".

Was the margin interest from dividends you paid when you shorted a stock? If yes, and you held the position for 45 calendar days or less, then you add the dividends paid to your cost basis, so in a way it is deductible.

If it is just interest to buy on margin or to short a stock (possibly one that doesn't pay dividends) then you're probably out of luck. However, the rules allow you to only deduct the amount of your margin interest that is less than or equal to your investment income (income from dividends, interest, short term capital gains). So if your interest is $53 and investment income was only $3, then you can deduct $3. As you're taking the standard deduction then this $3 deduction is lost. However, the remaining $50 gets carried over to next year. If you itemize next year, then you can use it then.

If you close the short sale by the 45th day after the date of the short sale (1 year or less in the case of an extraordinary dividend), you cannot deduct the payment in lieu of the dividend you make to the lender. Instead, you must increase the basis of the stock used to close the short sale by that amount.