recovery rebate

No you cannot change your return at this point. The IRS is busy changing it right now. Once the IRS finishes and all payments have cleared all banks, then you can file an amended return - if it reaches that point. The IRS may send you a letter requesting more information instead.

Also, be aware that the IRS and states communicate so you may need to file an amended state return if the IRS changes are kept.

You can file an amended return as soon as the original return is completely finished- all payments have cleared the banks, E-filing will shorten the refund delay. Please:

• Save a copy of the original return before doing an amended return.
• See how to file an amended return.
• Follow your amend at track an amended return 
• See Can I e-file my amended state return? or I need to amend my state return.

Here is a great FAQ to show the math for amended returns.