Tax Day, April 15, is looming for the nearly 142 million Americans who will file a tax return for income earned in 2009. While most taxpayers worry about paying the correct amount and even pay for professional assistance to make sure they do, many millions of tax filers will be "nonpayers," according to a new Tax Foundation study. A nonpaying tax return is one filed by an individual or couple who, thanks to legal credits and deductions, owes nothing. During 2008, more than a third of all tax returns resulted in complete nonpayment; that is, people got back every dollar that was withheld from their paychecks during the year.