I have worked at a large retail store in Manhattan for a year and about 60 days ago was promoted to manager of the store. I would told that I would receive health benefits. I just asked when these would kick in and was told by the GM that prior to being promoted I was considered part time. I told him that I had not worked less than 40 hours a week for the last 12 months and he said I would now have to wait a year before health benefits would be paid. I have reported this to the company HR and would like any help I can get to understand what my rights are.

Generally speaking, your rights are based on whatever the benefits plan document(s) says they are. I would wait until you hear back from HR before worrying about this too much.