Generally, the taxpayer must file their claim for a credit or refund within 3 years after the date they filed their original return or within 2 years after the date they paid the tax, whichever is later. As a result of COVID-19, the due date to file a protective claim for tax year 2016 individual income tax returns has been postponed until July 15, 2020. To file a protective claim for tax year 2016, taxpayers make sure their claim is properly addressed, mailed, and postmarked by July 15, 2020. For Forms 1040-X filed as “Protective Claims under the ACA litigation,” write “Protective Claim for refund under California, et al. v. Texas” at the top of Form 1040-X. Instructions related to Form 1040-X in IRS Publication 17 include: Protective claim for refund Generally, a protective claim is a formal claim or amended return for credit or refund normally based on current litigation or expected changes in tax law or other legislation. You file a protective claim when your right to a refund is contingent on future events and may not be determinable until after the statute of limitations expires. A valid protective claim doesn't have to list a particular dollar amount or demand an immediate refund. However, a valid protective claim must: Be in writing and signed Include your name, address, SSN or ITIN, and other contact information Identify and describe the contingencies affecting the claim Clearly alert the IRS to the essential nature of the claim Identify the specific year(s) for which a refund is sought.