Is it legal to keep me as freelance in NY?

I have been working for a certain company for 3 years as a full time freelance graphic designer in NY. When I had my taxes done in NJ, my accountant said basically if a job requires me to come to work 5 days a week continuously, I have to be hired as full time not freelance, and it wouldn't be legal in Jersey. He said he wasn't sure about NY laws. I've never heard of this law before. Is anyone familiar with this?