Wait, so I'm reading this thread b/c I also got surprised by this "You have a penalty for underpayment of estimated taxes" statement that popped up. We've owed (and completely paid) the IRS every year for at least the past 5 years and I've never seen this message before. (We've also never paid estimated taxes.) It's a small amount but I still want to know why we now have a "penalty" for owing tax.
