Yes, most physiatry employers will negotiate. That’s the obvious answer; everything is negotiable! Some items you can negotiate are the start date, some aspects of the work schedule and fringe benefits.
Some contract provisions are non-negotiable as all the doctors in the practice/hospital abide by these same provisions and it would be unfair to them and the practice/hospital to bend them just for you. These may include the productivity incentives and issues about termination.
Please note that some large organizations have standard contracts and will not negotiate.