My W-2 incorrectly reflects a Retirement Plan in Blk 13 and my IRA deduction was limited; must I get an amended W-2 and is doing and filing an amended return worthwhile?

I terminated from my employment in Oct15, however, was on severance several months into 2016 and thus received a W-2.  I did have a retirement plan while employed, however, that eligibility ended in Oct15.