The contracting out policy is one of the new instruments for the new public management. On the beginning of a new era, governments must face the implications of a increasing demand for new services, and an improved quality of the already existent ones, together with a growing needs for new funding resources.

Broadly, contracting out may help to save resources, create incentives for better efficiency, and better targeting for public policies. One of the mechanisms to carry out a contracting out policy is the voucher.

This document analyses both the theoretical aspects of vouchers, perhaps not widely treated in the literature, and its possible applications to most of publicly provided services. The objective is to offer an analysis that allows public managers to determine the possible implications of the use of these instruments. For that purpose a review of the international experiences is offered.