How Do You Fill Out Lines 20a and 20b on Form 1040?

Report the total amount of Social Security income received on line 20a of the IRS’ Form 1040, and on line 20b, report the taxable portion of Social Security income, as U.S. Tax Center explains. The total amount of Social Security benefits and income a taxpayer receives determines how taxpayers report Social Security benefits.

In determining if any of the Social Security benefits taxpayers receive are taxable, they should compare the base amount of their filing status with the sum of one-half of their Social Security benefits as well as all of their other income, including tax-exempt interest, as U.S. Tax Center advises.

For taxpayers who receive Form SSA-1099, box 3 provides the total amount of Social Security benefits paid, as Tax Map explains, and taxpayers should report Social Security benefits in the Income section of page one on IRS form 1040, Individual Income Tax Return. They enter the benefits on line 20a and the taxable portion on 20b. If using form 1040A, benefits are listed on lines 14a and 14b.

Some taxpayers find that receiving Social Security benefits requires them to file tax returns when they otherwise wouldn’t. The instructions that accompany IRS form 1040 provide a worksheet for taxpayers to determine if their benefits are taxable, as Tax Map details.