I received my 2019 1099-G State of Colorado Department of Revenue after I had completed and sent my return to be e-filed. Do I have to amend my return?

[brown2484-msn-co]

I did receive a refund that I need to add to my tax return.

[VolvoGirl]

That depends.  Did you take the Standard Deduction on your 2019 Federal return?

A State Tax Refund is taxable if you itemized deductions on that prior year's federal return and took a deduction for state income taxes instead of the sale tax.  You got a deduction benefit for it so now you have to include it as income. If you took the standard deduction it is not taxable and you don't need to report it.