People often ask me how long they need to hold on to tax returns and related documents. The hoarder in me says to keep them forever- just incase! But the IRS says that you really only need to hold onto tax return and supporting documentation (like W-2s, 1099s, deduction receipts) for three years after the date of filing (April 15th or later if you filed an extension).
There are a few exceptions to this though. If you under reported your income by 25% or more the IRS can look back six or even seven years. And if you don’t file a return or file fraudulent returns then there is no statute of limitations so the IRS can come after you at any time!
Can’t stand the clutter? You don’t have to hold onto paper records. The IRS will accept digital copies. I keep my important records in Dropbox.