Will I Owe an Underpayment Penalty?

It's not terribly uncommon for errors to be made when making contributions via Quarterly Estimates or wage contributions.  But if the amount that you're required to pay exceeds your current withholdings or estimates, you could be subjected to an underpayment penalty.  You can avoid the fine by paying 100% of your prior year's taxes, or a minimum of 90% of what is owed for 2015.