While most of the IRS is shut down, they are not changing the filing deadline for the 12 million tax payers who filed for extension during tax season.  There are a few exceptions to this: members of the miliary and others serving in Afghanistan or other combat zone localities typically have until at least 180 days after they leave the combat zone to both file returns and pay any taxes due.  Additionally, taxpayers with extensions in parts of Colorado affected by sever storms, flooding, landslides and mudslides have until December 2, 2013 to file and pay.

Also be aware, if you are expecting a refund, the IRS is no issuing them during the shutdown.