When you take money out of your 401k, you pay tax on it.
Once you reach a certain age you will be required to withdraw a certain minimum amount per year.
If you withdraw money too early there is a penalty
If you do something complicated, like contribute some money pre-tax and some post-tax, then you need to keep track of those amounts.
All of these need forms.
You may still need to report the information on the forms to the IRS on your tax return, especially if you have taxable earnings in your 401k or distributions from your 401k.
Because you need to report how much went in, or if you take any out
You'll need to be more specific on what the "tax form" is.
