I forgot to enter stimulus payment, how do I get back to it?

In the Federal section, select the Federal Review interview section at the top of the screen.

This will take you to the input section for the Recovery Rebate credit.

Be sure to indicate the actual amount of each stimulus payment you received on the page that asks if you received a stimulus payment. 

There will be two boxes and both need to be completed.  If you did not receive any stimulus payments, please indicate We didn't get a stimulus payment by checking that box.

Your input above will generate the Recovery Rebate Credit, if you are eligible.  Please see the attached link for more information on who can claim the credit.

Recovery Rebate Credit eligibility