I was hit on the left side of my vehicle by someone who was backing up, I was told I am 40 % at fault, how is that possible?

It is difficult to answer this question with the few facts you presented.  If you were not moving at all, then the other person would be 100% at fault most likely.  However, we do not know how the other driver described the accident to his/her insurance company.  Most of the time, the insurance company will side with its insured if that person's version will allow the company to pay less to the other party.  Steven A. Schwartz Attorney/Partner   JOEL H. SCHWARTZ, P.C. One Washington Mall, 16th floor Boston, MA  02108 (617) 742-1170 (800) 660-2270 (617) 250-2072 fax sas@joelhschwartz.com www.joelhschwartz.com