Eleven percent of the U.K. population holds private health care insurance, and £2.2 billion are spent annually in the acute sector of private health care. Although isolated from policy discussions about new medical technology in the National Health Service, the private sector encounters these interventions regularly. During 18 months in one company, a new medical technology was encountered on average every week; 59 leading edge technologies were submitted for authorization (18 on multiple occasions). There are certain constraints on purchasers of health care in the private sector in dealing with new technology; these include fragmentation of the sector, differing rationalities within companies about limitations on eligibility of new procedures while competing for business, the role and expertise of the medical adviser, and demands of articulate customers. A proactive approach by the private sector to these challenges is hampered by its independence. Poor communication between the public and private sectors, and the lack of a more inclusive approach to policy centrally, undermine the rational diffusion and use of new medical technology in the U.K. health care system.