I read this article in the newspaper of the Society of Thoracic Surgeons, one of the 2 cardiothoracic professional organisations in the USA. It highlights the direction of the travel of the employment status of American specialists in the dominant private sector.
Until fairly recently, outside academic institutions, most surgeons and physicians in America worked as either completely independent practitioners or as part of independent groups. Just as in private practice in the UK, these independants would essentially hire the hospital and their facilities to do their work.
Over the past few years, many have now foregone their independent status to become more closely aligned with hospitals and hospital groups - such physicians are known as hospitalists. This piece explains the circumstances and reasons behind the change.
In the UK, where the bulk of hospitals are in the public sector, specialists start from a situation which is at the polar opposite. I would not be surprised however if, with the NHS reforms, we will see a gradual loosening of the relationship between consultants and NHS hospitals. Many NHS organizations would probably welcome a lessening of their responsibilities (e.g. pension) towards relatively well paid employees .