If I receive my 2017 state refund in 2019, should I report it as income in 2018 or 2019?

[Anonymous]

if its taxable -  in 2019.  it may not be.  here  are some examples

you did not itemize in 2017

you paid alternative minimum tax and itemized but if your state tax deduction was reduced by the refund your total taxes wouldn't change

you took a sales tax deduction rather than an income tax deduction 

there are other situations that would make the refund wholly or partially non taxable.