Our OIC from the IRS was accepted in December 2011 and a lien was removed. We owed back taxes for 5 years, clearly listed on all OIC paperwork. The only stipulation was that we pay any owed taxes in full and on time for five years. We have the certified receipt showing it was received as such this year. Yesterday we received a notice from the IRS that we owe over $40,000 for two of the years that were listed as paid on the OIC. This makes no sense because it is the amount we owned for all 5 years before we filed the OIC. My husband was on the phone with the IRS for over two hours before he gave up trying to talk to someone who could help. One woman was very rude and said "you probably owe it." If this is true they are NOT honoring the OIC, what do we do if they insist we owe it?