It's very simple. Go here:https://apps.irs.gov/app/picklist/list/priorFormPublication.htmlThen type in the form type you want. All the old years will show up.WARNING: Sometimes it is not best to file all old returns.If you are not sure or need help with your tax issues give us a call us at (888) 515-4829 or go to https://trp.tax/contact-us/See our comprehensive tax help guide here:https://trp.tax/tax-help/