Why is it different? You probably had withholding taken out and Medicare deducted. Enter the SSA-1099 exactly as shown. You can enter the withholding and Medicare.
look down the left side of form SSA-1099, it should reconcile down to what was actually deposited into your bank account; as posted by others, the taxable amount is the top line and then reduced by medicare premiums which should net to what you received in your bank account. it's that gross number that is taxable income