If you are going to manually complete and mail the Form 1040-SR for tax year 2021 go to this IRS website for prior year forms and schedules - https://apps.irs.gov/app/picklist/list/priorFormPublication.html
IRS Form 1040-SR for tax year 2021 - https://www.irs.gov/pub/irs-prior/f1040s--2021.pdf
