Why did my refund increase after I printed and filed my return?

[Mooby]

My federal refund almost doubled after I printed and mailed it.

[SweetieJean]

Did you report a 1099-G for unemployment comp?  The program has been updated to reflect the new $10,200 deduction for that.  You generally do not need to amend for Federal.

However, taxpayers would have to file an amended return if they did not originally claim the EITC or other credits, but now are eligible because the [unemployment comp] exclusion changed their income.  These taxpayers may want to review their state tax returns as well.

IRS to recalculate taxes on unemployment benefits; refunds to start in May | Internal Revenue Servic...

See these re State:

How is my state taxing unemployment income? (intuit.com)

Do I need to amend my state return to update my un... (intuit.com)