Salary deferral contributions to 401(k) plans are required to be deposited into the trust -- that is, the plan account -- no later than 15 business days after the end of the month in which the salary was paid. An employer who fails to make a timely deposit would be subject to penalties.

And the money you lost can come directly from your former employer's pocket. According to the law, plan fiduciaries -- those, like your employer, who are responsible for safeguarding plan assets -- are personally liable for transgressions.