When filing an extension, you will estimate the amount of your income by referring to any income statements that you may have received in 2018 (e.g. Form W-2, Form 1099-MISC, payroll statements, checks, etc.). Any adjustments to income such as IRA deductions, alimony, educators expenses, are then subtracted from your income.
I have attached the Form 1040 Schedule 1, Additional
Income and Adjustments to Income. The adjustments to income begin on line 23 of the form.
