Caller ID shows it belonging to a Paul Johnson. I keep getting called(5 times in less than 28 hours) and then a recorded voice saying "That's an incorrect option, goodbye". I finally called them back and a male with a heavy Indian accent told me he was John with the IRS. He asked for my name, DOB, address, SSN, and other personal information to check if the "IRS" was suing me. I told him to never call again as it is a scam. I then blocked the number from future calls.
If they call DO NOT give them any information. It is a phishing scam and they will then use your identity, or keep spinning stories until you start paying them because they make it sound believable. The only problem is if you do start paying they will continue to come after you for all time.
The IRS follows standard, legal, court approved processes to let you know you are being sued. I.e. you get a process service priority USPS mail with signature confirmation, or a constable or deputy will serve the papers on you in person. None of this cold call bullcrap.