Hospitals, physicians and managed care plans are joining forces to contain health care costs by the formation of integrated delivery systems which coordinate the delivery of primary care and specialty physicians' services with a hospital's outpatient and inpatient services. Collaboration by physician-controlled entities with hospitals enables an integrated approach to managed care contracting and preserves volume and market share for the integrated network's participants. Murtha Cullina has been active in this movement. Our experience has included the provision of legal services along the full spectrum of physician-hospital collaboration, including the formation of management services organizations ("MSOs") (to enable hospitals to offer recruitment and retention practice enhancements to physicians consistent with anti-kickback and IRS limitations) to the formation of PHOs and more integrated entities suitable for hospital/physician collaboration, including economically integrated clinic model physician groups.