This year, Santhosh, a single taxpayer, estimates that his tax liability will be $95,500. Last year, his total tax liability was $13,500. He estimates that his tax withholding from his employer will be $33,500.

Required:

1. Is Santhosh required to increase his withholding or make estimated tax payments this year to avoid the underpayment penalty?

2. By how much, if any, must Santhosh increase his withholding and/or estimated tax payments for the year to avoid underpayment penalties?