H.R.5172: To amend the Internal Revenue Code of 1986 to provide recovery rebates to certain individuals receiving social security benefits.

Immediate Financial Assistance for America's Seniors Act of 2008 - Amends the Internal Revenue Code to allow social security recipients with earned income less than $3,000 a $300 refundable tax credit ($600 for married couples filing a joint tax return) in 2008. Reduces the amount of such credit by 5% of the amount by which the taxpayer's adjusted gross income exceeds $75,000.