Question:
I was out on FMLA when I received notice that I was being laid off, can my employer do that?

Response:
If your employer based their decision to lay you off because you were on FMLA, then no they can not do that. But if you were included in a group of lay off’s and the criteria in which they used to pick individuals for lay off was one in which you would have been included if you were there, then your employer can in fact lay you off while you are out on leave.

Overview

Covered employers must grant an eligible employee up to a total of 12 workweeks of unpaid leave during any 12-month period for one or more of the following reasons:

* for the birth and care of the newborn child of the employee;
* for placement with the employee of a son or daughter for adoption or foster care;
* to care for an immediate family member (spouse, child, or parent) with a serious health condition; or
* to take medical leave when the employee is unable to work because of a serious health condition.
Continue Reading here:
http://www.dol.gov/esa/whd/fmla/