USERRA and make up deferrals

[30Rock]

Hi - I have not been able to find any source that affirmatively states that make up 401k deferrals for the period of military service must come from current year compensation. So for example - employee is on military duty in 2012 and 2013 and returns in 2014, He would like to make up $50,000. So his compensation for 2014 will be $40,000. Can he submit a check for $50,000 OR does the $50,000 have to come from current compensation, which in effect will equate to 100% of compensation and he can only defer $40,000.

I have heard there was a technical correction to USERRA that requires the missed deferrals come from current compensation - so that the employer is not on the hook for huge amounts of match from prior years.

Any help would be great!!