Did you already file a 2020 tax return? If so you have to wait until the return has been FULLY processed in order to amend and add a dependent. When you add a dependent, you enter the dependent's information in My Info.
To claim a grandchild as your dependent
When you enter the child’s name in My Info, you will be asked “What’s your relationship to [child’s name]?”
Choose “another person”
a drop down menu will appear that lets you choose grandchild
Select your tax year for amending instructions:
Even during “normal” times it takes about four months for the IRS to process an amended return. During the pandemic and due to the severe backlog at the IRS it is taking much longer—six months or more for many amended returns. Do not expect quick results from amending. When the IRS issues a refund for an amended return it will be by check. They do not make direct deposits for refunds for amended returns. You can watch for information here: