I did some searches on this number and was shown 2 possible locations, one was Dassel MN and the other Little Falls, MN. The I did a search for IRS offices in both towns and guess what? Neither town has an IRS office. This is a scam, block their calls.
I had a message left on my answering machine in the effect "the IRS has a lawsuit against me" and to return their call. so stupid me; I called them back. The guy "Jason Brown" who evidently had a strong accent; said that if I didn't agree to make payment someone would be at my door in 45 minutes to take me to jail. ... I'm still home :)
I also just received a call from this number and was checking to see if it was a scam. So thank you to all of you for posting so I could find out and not call back.