Deciding which accounts you'll withdraw money from – and when you'll take it – is an important decision in retirement. However, you may want to consider preserving assets held in a taxable brokerage account and passing them down to heirs. That's because taxable investments benefit from a step-up in basis, which is a tax loophole that resets the cost basis of an investment to its current market value when the original owner dies. As a result, whatever gains the investment made during your lifetime become tax-free.