If you have been a victim of identity theft and have reported this info to the IRS , you should be receiving a letter from them - 4869CS. Please keep this letter safe and take it to your preparer when you get your tax return prepared. It will help speed up the processing of your return.
If you have not notified the IRS about your identity theft, please check out this post explaining what forms you will need to fill out.
FYI - the Identity Protection Specialized Unit has changed their FAX number to 978-684-4542.