You will receive a 1099-R from the plan trustee. It may be already available online, if not, they are supposed to mail it by January 31. If you have moved, you should call them to make sure they have the correct address. The 1099-R form will show the gross amount of the distribution and the tax withheld. The plan trustee will report on form 1099-R that it was a non-qualified withdrawal (not over age 55 in the year of separation or not over age 59-1/2 overall) and then the tax forms will add the penalty.
