The answer is generally no, the IRS doesn't throw people in jail just because they owe money in taxes. Rather the way the IRS deals with issues is by taking an increasingly serious set of collection actions designed to get you back in compliance. When people owe money to the IRS, jail time only comes into play when they're willfully avoiding their obligation to pay and so as long as you're taking action to get in compliance and aren't trying to do things to subvert the IRS, you're probably not going to go to jail for your liability. However, even with jail off the table, civil collections is not a fun place to hang out so it's best to resolve your issue as quickly and efficiently as possible.