Mid Year HCE Safe Harbor Inclusion?

Notice 2020-52 made it clear last year that safe harbor contributions for HCEs can be suspended mid-year without effecting the plan's safe harbor status (notice required), as contributions made for HCEs are not included in the definition of safe harbor contributions.

Since safe harbor contributions are generally required for the entire plan year, would I be correct that a mid year amendment to include HCEs back in the safe harbor match would not be permitted?  For example, HCEs are amended out of the safe harbor in 2020.  2021 the company begins to recover and would like to add the safe harbor back for the HCEs.  NHCEs were never affected.

Yes, it can be done, retroactive to the beginning of the plan year?  Or, no way, need to wait until next year?

Thanks very much.

See Section III.D.4 of IRS Notice 2016-16:  https://www.irs.gov/pub/irs-drop/n-16-16.pdf.  Other than clarifying that the match for HCEs is not safe harbor match, I don't see that Notice 2020-52 directly pertains to your issue.

A matching contribution for a safe harbor that that is not part of the safe harbor match may be increased with a mid-year amendment.  There are conditions.  Must be at least 3 months left in the year.  Must be retroactively made for the whole year.  A new safe harbor notice describing the amended match formula must be distributed.

As an alternative, look carefully at the amendment that suspended the match for the HCEs last year.  Maybe it left the possibility for resuming the match for HCEs as a discretionary match, in which case no mid-year amendment might be needed and you can avoid the above rules.

Good luck!