https://www.mercurynews.com/2021/04/05/who-will-get-plus-up-stimulus-payments-from-the-irs/ > (CNN) — The Internal Revenue Service started sending what it calls “plus-up” payments last week to people who are owed a bigger stimulus check than they initially received. > The original payments were based on 2018 or 2019 tax returns. That means people who earned less in 2020 could be owed more money. Once they file a 2020 tax return that shows a lower income amount, the IRS will automatically send them an additional payment.