Although this Revenue Ruling specifically applies only to whole hospital joint ventures, it sets out an IRS view that is likely to be applicable in other cases. Many prior rulings have allowed joint ventures related to a hospital’s mission where others clearly control, such as a venture with physicians for an MRI. Where the venture activity is such a significant part of the charity’s overall operation, however, the IRS seems to be applying a different standard. If you have control, there should be no problem. If you don’t, you will want a ruling that it is not such a significant activity that it will cause a problem.