My employer 401k plan offers 'after tax non Roth' contributions, in addition to traditional pre-tax and Roth. I chose to max out my pre-tax contributions at $19,000 this year and then switch to 'after tax (non Roth)' in order to make additional contributions (with the intention of converting those after tax contributions to Roth). The plan also does a basic Safe Harbor match...dollar for dollar on the first 3% and then 50% on the next 2%. So I can get a total of 4% match as long as I contribute at least 5% (which I am definitely doing).
The plan also has a "true up" feature so that when I front load my contributions like this I will not miss out on any match. If I max out my contributions half way through the year and then stop contributing before I've received the full 4% match they will calculate the difference and dump in that extra amount after the end of the year to "true up" my match.
I ended up doing well and earning more than expected when the year began meaning I maxed out my pre-tax contributions at $19,000 early in the year and then I just realized that my 'after tax' contributions just went in excess of $37,000 for the year putting me over the combined 415c limit of $56,000. I asked my employer to remove $7,000 to get me below the limit and also allow for a couple thousand dollars of match that I should be due via the year end 'true up', but my administrator told me that they will only refund the exact dollar amount to cap me right at $56,000 today and that I will forfeit the additional safe harbor match that I would normally get in the year end true up because I'm already at the limit. Does anyone know if this is allowed in a Safe Harbor plan??