Does/Did the state of NJ tax employee contributions to 401K plans as if they were ordinary income ? Working through NJ taxes on RMD income.

[neal6]

I have data on my 401K and contributory IRA contributions going back many years and use the post  tax contributions to reduce federal taxes on my RMDs. I would like to see if I can also reduce my NJ state taxes also. I have records, eg W-2 forms and returns for most years.  I cannot figure out if NJ taxed 401K contributions as ordinary income in prior years.  My employer's old W-2s show a similar number in Box 1 and in Box 17, state wages.

[SweetieJean · Accepted solution]

Beginning on January 1, 1984, New Jersey’s treatment of 401(k) Plan contributions changed. After that date, employee contributions to 401(k) Plans were no longer included in taxable wages when earned. If you made contributions to a 401(k) Plan before January 1, 1984, your distribution will be treated differently than if all the contributions were made after this date. 

See page 32 here:

https://www.state.nj.us/treasury/taxation/pdf/pubs/tgi-ee/git1.pdf

[neal6]

Good reference, but on page 8, not 32.