Are state income taxes paid in 2008 for tax years 2006 and before deductible on my 2008 return and will I save?

will this reduce my federal taxes due for 2008? Im using Turbo Tax and when I enter additional state taxes I owed for 2001 - 2006, it doesnt reduce the amount I owe in federal taxes for 2008. Is there some sort of time limit or dollar limit?

Public Comments

1. Yes, it will reduce your taxable income but only if you itemize. If you take the standard deduction it will make no difference on your Federal Return.
2. The additional taxes (but not the penalties or interest) is an eligible expense. However, you need to be able to itemize to see a difference and these can trigger AMT.