There's a lot of concern today that paying fees to medical providers for each service may lead to unnecessary care. But there's no easy way to replace the massively complicated fee-for-service system. One of the fashionable suggestions for new-style payment is "bundling", in which providers typically get a set amount that is supposed to cover an episode of care – a surgery, say – or a disease state such as diabetes. But a new study published in Health Affairs raises questions about the feasibility of bundling. The researchers, from the Rand Corporation and the Harvard School of Public Health, looked at three sites that were trying to implement a bundling methodology developed by the nonprofit Health Care Incentives Improvement Institute.