Generally the collection statute is 10 years from the date that your liability was assessed. (If you need assistance in calculating the remaining time on your collections statute, call 1-800-829-1040).
Making an offer in compromise extends the statute of limitations for collecting the tax liability that is the subject of the offer for the period that collecting the tax by levy is prohibited. The tax cannot be collected by levy while the offer is pending and if the offer is rejected, for 30 days thereafter.