"All 401(k) plan contributions have deposit deadlines -- and it's up to 401(k) fiduciaries to meet them.... [C]onfusion can easily lead to late contributions.... [C]onsequences for the employer ... range from mild (losing a tax deduction, making participants whole for lost earnings) to severe (plan disqualification, IRS and/or civil penalties).... [This article includes] a summary of the deposit deadlines applicable to all 401(k) plan contributions -- including how to correct late contributions."