The IRS will accept a penalty abatement petition if you had the inability to pay your tax debt due to circumstances that were out of your control.  Some examples may include the following:
1.  You were unemployed.
2.  You or a loved one experienced a serious illness or injury that prevented you from paying the IRS.
3.  Your records were destroyed by fire or by a natural disaster that was out of your control.
4.  You were misinformed or did not receive proper information from an IRS employee.

There are other reasons that you may be to get your IRS penalty petition approved.  A certified tax professional will be able to guide you through the process.