tl;dr - mostly just a gripe!
BTW, that should be CP2000
Back in 2013, when I was tidying up my Keogh as part of my retirement prep, I sold my shares in Blackstone … or so I thought. From Fidelity's perspective the shares were sold. On Blackstone's end however (presumably because it was Friday 13th) a mistake was made, and somehow I became some sort of 'partner.' Thenceforth, I started receiving Form K1's with sundry drivel, describing 'my share' of Blackstone's financial machinations. Said K1's were duly binned!
FF to my 2016 tax return, and I made a material omission, that pushed me into an IRS review. The IRS sent me a CP2000, which essentially flags discrepancies between what I report, and what others have reported. Lo and behold, my Blackstone 'partnership' was itemized alongside my other omission, and the IRS invited payment.
I called up Blackstone's investor relations department, who together with Fidelity, were able to remove me from their books -- I am now no longer a partner. So, I asked, how do I go about getting my tax obligation reduced? Answer: Oh, you'll have to get your accountant to file form 8082! Thanks!!!
Having googled form 8082, I suspect that having that form completed correctly will cost substantially more that the $80 that the IRS is asking; especially since I don't have an accountant, and it'll cost that much just to have them review my taxes in the first place.
Moral: If you receive spurious Form K1's around tax season: call up and get them taken care of on a more timely basis than I did!
Also: Let the heavens resound with my ill-feelings towards Blackstone's 'partnership' organization!