Union plan which is frozen

[fiona1]

DB plan - been hard frozen for several years - covers union employees only.

I'm trying to determine if the plan is subject to coverage and/or minimum participation. I'm pretty certain that coverage isn't necessary. No HCE's are benefiting - and union employees are deemed to pass coverage.

But I'm stumped with minimum participation. From what I can tell in the ERISA outline book - frozen plans are "deemed to satisfy §401(a)(26)" but they are still subject to the prior benefit structure test.

I can't really tell if union employees are deemed to pass minimum participation / prior benefit structure - as they are deemed to pass coverage.

Any thoughts?