The form you would have included in your tax returns if you had reported your non-deductible IRA contributions is Form 8606 - Nondeductible IRAs. This form can be filed along with a tax return, or as a stand alone form. You can complete a Form 8606 for each year, and submit to the IRS all at once. To access Form 8606, including the instructions and prior years' forms, go to: https://www.irs.gov/forms-pubs/about-form-8606
To access prior year forms, click on "All Form 8606 Revisions"
