<p>English health policy has promoted the diversity of providers of health care to NHS patients in recent years. Little research has been done to map the extent of actual and possible supply. Using data from four local health economies England the authors found that there was a low supply of such organisations, but that it is growing. Despite the greater emphasis placed by policy makers and researchers on non-profits, there were substantially more for-profits. This suggests they should be subject to further scrutiny, as the pressure to increase diversity of supply increases under the Coalition government.</p>