457B tax question

I will be receiving the first of three annual distributions from a 457b plan this year in the state of NJ (approx $200K.) The employer made no contribution to the plan. State tax was paid on my contributions.  Assets grew to about $80,000. (contributions approx $120K.)  Which accounting method would I use to calculate my state tax liability?  The reason is trying to determine if I will owe state tax next year and apply some of this year's refund or will I owe tax after I receive $120K?