In all health systems, providers must be paid for their services. That payment can come from two sources: directly from the individual patient, or from an organization paying on behalf of the patient—or some mix of the two. This note focuses on the second type of payer, described in this paper as a ‘strategic purchaser’ of health services, to distinguish it from the patient as a purchaser. This paper looks at the form that strategic purchasers take, how they can be held to account, and their autonomy.