Generally, you must file a claim for a credit or refund within 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later. See http://www.irs.gov/publications/p556/ar02.html#en_US_201312_publink1000176993
Since the original return was filed in 2010, three years from then would be in 2013.
Note that it is the date filed and not the date due that starts the three years when filing after the original (unextended) due date. So, although extended to Oct. 15 if filed earlier the three years may have passed.
Please be aware that the return has to be sent on or before the three year limitation.
Even though the government is not open, it is advisable for you to mail in this return with return receipt for proof of date mailed to try to get it in within the three year limitation if it has not passed.
Please ask if you need more discussion or clarification.
I never filed a federal income tax return for 2009 (I did file a 2009 California income tax return). Therefore, the answer you gave is not obviously relevant. Given this fact, what is the answer to my original question?
You have there years from the extended due date if you did extend and not file.
Under Internal Revenue Code section 6511(b)(2)(A), the IRS can issue refunds for a particular year if you requested an extension and subsequently file a tax return within three years from the extended deadline.
Hope that clarifies for you.
Please do ask if you need more help.