You took money out of a 401k for a down payment? Money taken from a 401k is not an exception to the 10% early withdrawal penalty. The distirbution you took will be taxable along with your other income and you will owe the 10% penalty if you are under 59 1/2. You need to enter the 1099R you got for the withdrawal on your tax return:
Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your
1099R.