Do you lose healthcare benefits if your hours are involuntarily reduced at work, temporarily?

I've been hired into this company as a part-time employee, but almost never has had a permanent place of work. In other words the company floats me around different clinics, temporarily. Recently, they have offered me another "temp" position and the worst clinic of all, with the worst schedule. I'm in overkill with the issue. I never signed up for this float mess, and feeling used/abused. I clearly was hired as a part-time nurse, but have been manipulated into all types of postions/schedules. My question is, if I opt for per diem until a permanent position becomes available, will I lose my healthcare benefits?