In certain cases when income tax refunds are delayed, IRS is required to pay interest on those refunds.  The exact rules about when this applies can get complicated, but in very broad terms, anyone who received (or will receive) a 2019 tax refund after the end of May will also be paid interest.  IRS began sending out those payments on August 19^th to eligible recipients.  If you used direct deposit for your refund, that’s how your interest will be paid as well, otherwise you should receive a check that has the code “INT Amount” on it.

If you haven’t yet received your refund, the interest will probably be added on to it rather than paid separately.

Taking a bit of shine off this good news, remember the interest you receive will be taxable income on your 2020 return.