Mar. 29--Remember that economic stimulus check you received last spring?

You might be eligible for an additional amount. Households that didn't receive a check or received only a partial payment may be able to use the "recovery rebate credit" on their 2008 tax returns. For example, households that had a child during 2008 could be entitled to an additional $300 from the rebate credit.

Determining whether you're eligible requires making a few calculations on the work sheet in your tax return instructions. To help with the process, the IRS provides a recovery rebate credit calculator on its Web site, www.irs.gov.

The amount of any stimulus payment you received in 2008 is a key part of the calcuation, but it should not be entered directly on your return.

If you received a stimulus check and can't recall the amount, you can find the figure by using the IRS Web site or by calling the IRS Economic Stimulus Line at (866) 234-2942. In either case, individuals must provide the IRS their filing status and number of exemptions shown on their 2007 tax return, along with their Social Security number.

For filers using Form 1040, the recovery rebate credit appears on line 70. It's on line 42 of 1040A and line 9 of 1040EZ.

Homeowners who don't itemize will get a temporary tax break this filing season. They can add what they paid in real estate taxes last year to their standard deduction. That's likely to be valuable to many elderly homeowners who have paid off their mortgage and no longer itemize, said John W. Roth, senior tax analyst at CCH Inc., a major publisher of tax, accounting and audit information.

The ceiling on how much can be added to the standard deduction is $500 for an individual filer and $1,000 for a married couple filing jointly.

One highly touted part of the government's stimulus package has been a tax break for first-time home buyers. It started out last year as a credit for as much as $7,500 for those who bought a primary residence between April 9, 2008, and June 30, 2009.

"It really wasn't a credit," Roth said. "It was an interest-free loan" that had to be paid back within 15 years.

Earlier this year, the homebuyer tax break was sweetened. The credit ceiling was raised to $8,000, and the repayment requirement was dropped. The IRS also has been taxpayer-friendly when interpreting several details, including the eligibility of two unrelated individuals who buy a home together, Roth said. To be eligible for the credit, a first-time homebuyer must make the purchase by Dec. 1.