I just got this call a few minute's ago. This is a straight up scam looking for people to bite. The IRS sends letters if owe them, they do not call you.
Just received a SCAM voicemail from 1-202-840-6551 - that stated: "Hi this message is intended to contact you - My name is Kevin Mason and I am calling regarding an enforcement action executed by the U.S. Treasury intending it's receiver's attention. Ignoring this will be an intentional attempt to avoid initial appearance before a 'magistrate' judge or a grand jury for a Federal criminal offense. My number is 202-840-6151 (misstates the number as the ID read 202-840-6551) I repeat 202-840-6151. I'd like you to cooperate with us and help us to help you." Same "Indian" voice from last time... Blocking this number!! Wish the NSA could get rid of these idiots!!