Maybe not. The IRS must charge you interest on your tax bill, but penalties are discretionary. The IRS abates (cancels) one-third of all penalties it charges. The trick is to convince the IRS that you had "reasonable cause" (a good excuse) for failing to observe the tax law. Examples that might work include:
Start the process immediately. As soon as you receive a tax bill with penalties that you don't want to pay, write back and ask for an abatement. The best way to get the IRS's attention is to use IRS Form 843, Claim for Refund and Request for Abatement. You can also send a letter explaining why you incurred the penalty. Be sure to attach a copy of the IRS notice showing the penalty and any other documentation that helps explain your situation.