How do I amend my 2020 tax return to add my son as a dependent step by step?

• How to amend (change or correct) a return you already filed   

Start the amendment process and follow the interview screens to go back to the MY INFO section to add the child then continue thru the deductions section to update the credits.  Then complete the REVIEW & FILE tabs.  

if your son was born in 2020 it is crucial that you select that he lived with you all year.