WASHINGTON, Feb. 28 (UPI) -- Letters outlining eligibility to receive a rebate at the center of an emergency economic stimulus package are in the mail, the U.S. Treasury Department said.

"For the majority of Americans, all they will need to do is file a tax return," Treasury Secretary Henry Paulson said Thursday.

The IRS will be working with governmental agencies and other groups to reach out to people who normally don't file a return to "ensure they know how to get their stimulus payment this year," Paulson said.

In the letter, Paulson said the Economic Stimulus Act of 2008 would provide payments to more than 130 million American households.

"Under this new law, you may be entitled to a payment of up to $600 ($1,200 if filing a joint return), plus additional amounts for each qualifying child," the letter said.