I pain into 401k don't I need to use 1040A instead of 1040 EZ

[dmertz · Accepted solution]

Contributions to a 401(k) do not require you to file Form 1040A unless the contribution qualifies you for a Retirement Savings Contributions Credit.  However, distributions (taking money out) from the 401(k) reported on Forms 1099-R do require that you file Form 1040A or Form 1040.

[dmertz]

I added to my answer to account for the possibility of a Retirement Savings Contributions Credit.