The IRS has a ten (10) year statute for collection of unpaid tax, penalties, and intererest.
If you file a bankruptcy, and you do not receive a Discharge, the time of your bankruptcy is added to the ten year statutue.
If you submit an Offer in Compromise (OIC), and the IRS rejects your OIC, the time of your OIC, PLUS additional year is added to the the ten year statute.
I have helped numerous clients submit an OIC, and then have their OIC accepted by the IRS.
Please call me at 702-589-7557 if you owe the IRS more than $250,000.