Is there a statute of limitations on IRS penalties?

Yes, IRS penalties are subject to statutes of limitations, but the timelines differ depending on the type of penalty. For assessment (the IRS's deadline to impose penalties): the general statute is 3 years from the filing date of the return. If you underreport income by more than 25%, it extends to 6 years. For fraud or unfiled returns, there is no statute of limitations, meaning the IRS can assess penalties at any time. For collection (the IRS's deadline to collect assessed penalties): the standard Collection Statute Expiration Date (CSED) is 10 years from the date of assessment. After 10 years, the IRS must write off the debt including penalties. However, certain actions toll (pause) the 10-year clock: filing an Offer in Compromise, bankruptcy, being outside the US for 6+ months, or requesting a Collection Due Process hearing. For penalty abatement requests: there is generally no time limit for requesting First Time Penalty Abatement or reasonable cause abatement, even for penalties assessed years ago. If the penalty was assessed within the last 3 years and you paid it, you can request a refund using Form 843.