W-2's for union employees

[Guest JPIngold]

If an employer (ABC Co.) pays into the union pension fund (Local 123) for an employee, is that person an active participant for purposes of the ABC Co. W-2??? From a theoretical standpoint, I would think "yes" because how else will that employee know his IRA contributions should be subject to deduction limitations, but from a technical standpoint, he is not an active participant in the ABC Co.'s retirement plan.

[masteff]

I'd err on the side of discretion (meaning mark the box), especially since the employer made contributions for that employee. I can't find the exact trail of code and regs that connects from Section 219(g) to the W-2, but as the W-2 is a duty of the employer, I'd say it's the employer and not the plan that matters (and the employer knows it made contributions to a 401(a) trust).