Go to this IRS website for stimulus payment information FAQ's (Question 15) - https://www.irs.gov/coronavirus/economic-impact-payment-information-center
A15. You DO NOT need to take any further action if you filed a federal income tax return for 2018 or 2019. If you already filed your tax return for 2019, the IRS will use this information to calculate the Payment amount. If you haven’t filed your tax return for 2019 but filed a 2018 federal income tax return, the IRS will use the information from your 2018 tax return to calculate the Payment amount.