Only 13% of taxpayers itemize, so 87% automatically won't have to pay tax on the refund. Out of the 13%, only those who didn't pay at least $10k in state tax will have to claim the refund as earnings. Since the vast majority of people who itemize are high earners, this is a very small number of people. I'd suspect the percent of people who will have to pay tax on the refund will be in the very low single digits, maybe even 1% or less of the population.