I received this letter as well and called the IRS. The woman helping me said she did see that notice was sent to me and that I did not claim the EIC (why turboxtax, why?!). She directed me to the IRS website to download the form, but it wasn't there. After some looking on her part she found that the form isn't available on the website likely due to a glitch in their system. She mailed me the form. I should receive it in 5-10 days.
