Possibly. It depends if you itemized deductions are took the standard deduction. If you took the standard deduction and the extra information does not change that status, then no amendment would be necessary. Keep the refi information for your records.
If deductions were itemized, then the cash out refi used for repairing and improving your home would need to be included. It is fine to begin the amendment now to calculate the difference in the tax.
It may save you some time to correspond directly through the contact information on the notice to resolve the situation.
For more information, see: I got a letter or notice from the IRS.
What kinds of refinancing costs can I deduct?
@BearCon2020_
