I e-filed my 2018 tax return last week, but just received a 1099-G for a state tax refund I received last year.  I did not itemize deductions last year (2017) nor this year (2018).  It is my understanding the state tax refund is not taxable since I did not itemize; however, do I need to go ahead and file an amended return for 2018 to show the state tax refund I received last year even though it has no impact on my return for this year?