After reading the previous replies, I still have a two part question.  If
you begin working for a company toward the end of their year plan and 
enroll in the plan for a partial year (4 months)... are the expenses
only for those months reimburseable.  If you start in Nov. & the Plan
ends Feb 31st.  Only expenses occurred in Nov,Dec, Jan & Feb are
eligible?  Also, what if company didn't take the money each month
(forgot) and took  one lump sum 3 months later?

Our rule is as follows: only expenses that occurred during the
enrollment time are covered.  In your example, I assume that plans go
from January -> December.  The reason they end the plan on Feb 31st is
so you can submit your expenses that occurred towards the end of the
period (November and December).  Jan & Feb are not eligible for the
previous year.  Does that make sense?