If I get Medicaid but am offered private insurance with work but cost too much can I stay with Medicaid?

I currently have Medicaid and just  recently got offered health insurance at work. I was excited until I started looking at my options and realized that it would take at least half my paycheck each time to get the minimum I need and I just can't afford that. I have done a lot of research on this topic and can't find an answer. I woul like to know before I have to sign up on February 14th. I don't want to get penalized if I can't stay with Medicaid and then have no insurance because I didn't sign up with the work provided health insurance since it is a high cost.