Tax deductible and plan termination with no eligible compensation

The plan terminated 12/31/2018.  Employer failed to make required contributions in prior years and made them in 2019.  Let''s assume that they never deducted these on prior years tax return and we're self-correcting under EPCRS.  Since there are no eligible compensation under 404,  is this subject to excise tax on the 5330?  Or these non-deductible contributions? 

NVM...found the answer. 

Please, it's OK to share what you found.  And the source. 

Sure thing...per ERISA book.

"Under the regulation, the 404(a)(3) deduction limit for any taxable year following the termination of the plan is computed by taking into account the compensation of the employees who were benefiting under the plan at any time during the one-year period ending on the last day of the last calendar month in which the plan was terminated."

Let take this further...what happens if the termination date was 12/31/2017 or prior?