If all I have is a 401k contribution, can I use free turbo tax

[DoninGA]

A 40(k) contribution to an employer's plan would have been entered on the W-2 in box 12 with a code of D.  The contribution is not entered anywhere else on the tax return.

A withdrawal from a 401(k) is reported on a Form 1099-R which would have sent by the plan administrator in January.

The Free edition supports entry of a 401(k) withdrawal on a Form 1099-R if there are no penalties associated with the withdrawal.

[macuser_22]

With an exception.   If your income and contribution  qualifies you for the Savers Credit (form 8880 and Schedule 1) then the Free Editions does not support any additional schedules.