Under the Stark employment exception, hospitals can establish a productivity bonus based on the physician's personally performed services. The bonus can be calculated off of the collections. You will need to determine if the aggregate compensation, assuming the physician meets the thresholds, if fair market value. I would test the arrangement assuming 90th percentile collections to determine what the resulting compensation would be to see if it can be defended as fair market value. The biggest issue is to make sure that the bonus is based only on the physician's personally performed services and not ancillary services ordered by the physician that the physician does not perform or personally supervise.