Sometimes you will get a Form 1099 or Form K1 after you already filed your income tax return.  Sometimes you will “remember” that W2 or 1099-MISC that you should have gotten in the mail but didn’t (like when you move and don’t tell your old employer).  No matter what the reason is, sometimes you simply need to make some changes to your return.  But what changes require you to file an amendment and just how do you go ab