New 401(k) plan 2015 with pre-tax and Roth deferrals, enhanced SH match and integrated PS - 8 participants including one HCE.
TPA used incorrect formula to calculate SH match - basic tiered match instead of 4% enhanced match. Match was contributed timely but at least three participants received less than they should have received, totaling several hundred dollars for 2017 plan year. Plan document and SH notice all say enhanced 4% match. No discretionary PS contributions made.
2017 can be corrected using EPCRS. We haven't seen the numbers yet for prior years but it's possible the same error has been made from the beginning.
What options are available if SH match was under-contributed for 2015 and 2016?