You may deduct capital losses up to the amount of your capital gains, plus $3,000 ($1,500 if married filing separately). If part of the loss is still unused, you can carry it forward to later years until it is completely depleted. This "unused loss" includes any amount appearing on Line 13 of IRS Form 1040 that is not of benefit to the bottom line of the return. While the amount will appear on that line, the worksheet calculation will take into account that the amount is not actually being used in the current year, and the entire amount will transfer through the worksheet to the following year when import is done from one year to the next.
Any capital loss carryover to the following tax year will be calculated in TaxACT, and if the return is imported to the following year's return, the amount will automatically be transferred.