The Australian Health Management Group (AHMG) offers disease- and risk-management programs for members, aimed at improving health status and reducing health care costs. As an incentive to re-enrol, members are posted a small gift upon receipt of their completed enrolment form. The purpose of the present study was to determine whether the provision of an incentive has a measurable effect on re-enrolment rates. Members were allocated to one of three conditions: “gift”; “competition”; or “no incentive”. We found that the provision of an incentive resulted in an increase in re-enrolment rates, with little difference between the “competition” and “gift” conditions. However, the cost per additional re-enrollee is considerable, thus a more detailed analysis of the costs and benefits of offering incentives need to be undertaken.