What is the "ut" code on line 60 mean?

[LeonardK]

Thank you for contacting us here at Turbotax! 

If you have a code UT on line 60 of your 1040 then you have entered an amount in box 12 of your W-2 with a code of A, B, C, M, or N. Please verify that this is correct on your W-2.

• If this is incorrect and your W-2 (hard copy) does not list one of these codes, go into the W-2 entries and be sure that one of these codes did not get selected accidentally.
• If this is correct and you do have one of these codes in Box 12 of your W-2, per the IRS instructions, this amount is appropriately placed to the left of Line 60 with the code "UT".

[SweetieJean]

Uncollected Tax - Form 1040, Line 60

[djorna11]

What about codes D, W, or DD?  What do all of the codes represent.  More information please.