Determining catch up contributions in fiscal year plans

[Guest Diane DuFresne]

Working on a 3/31/13 plan year end 401(k) non-standardized plan. This plan has elected to use the determination period for compensation as the calendar year coinciding with or ending within the plan year. The limitation year is then the same as the determination period.

For ADP testing purposes, we are using the 2012 calendar year compensation and the 3/31/13 plan year deferrals.

The 402(g) deferral limit for 2012 is $17,000 and the 402(g) deferral limit for 2013 is $17,500.

What deferral limit is used for the 3/31/13 ADP test to determine the amount of the catch up contributions?