The TaxAct® program will determine what amount (if any) needs to appear on Lines 4a and 4b of IRS Form 1040 according to the IRS instructions and the data entered in the program. Usually, if the amount is fully taxable, Line 4a is left blank and the total distribution is entered on Line 4b. Exceptions to this are listed in the IRS Instructions for Form 1040.
To enter the information from Form 1099-R that is used to calculate these amounts: