MMC Benefits Handbook
If You Take a Leave of Absence
Because Company matching credits are conditioned on your deferrals and are made only when you are deferring to the Plan, they will be suspended when you take an unpaid leave of absence (including long term disability).
Your deferrals and Company matching credits will resume automatically upon your return from a leave of absence within the same Plan year. There will be no retroactive deferrals or Company matching credits for the period of your leave.
If you take a paid leave of absence, contributions will continue during the leave.