A withdrawal from a 401(k) and you are under the age of 59 1/2 is not eligible for the 10% early withdrawal exclusion for a first time home purchase. That is only available if the withdrawal is from an IRA and only on the first $10,000 withdrawn.
The taxable amount of the 401(k) withdrawal is entered on a federal tax return as ordinary income. You will receive a Form 1099-R for the withdrawal in January of the year following the withdrawal. The 1099-R is entered on the federal tax return as received.
