My company has filed my PERM labor based on Masters Degree +6 months experience. Since i had worked as graduate Assistantship, lawyer suggested to make it Master's + 6 months experience so that they could reject fresh graduates applying for the Job.

But, my company also had filed green card for my coworker last year with MS + 0 yrs experience and her Labor as well as I-140 was approved without any issues. It depends on the job as well as the requirement. 

I am working as a Biostatistician and Masters Degree is usually the minimum requirement.