The migration "carousel" for health workers - or human resources for health (HRH) - is a phenomenon ripe with opportunities and difficulties for its many stakeholders. With an in-depth literature review, the situation is put into context, in terms of the underlying factors that prompt workers to relocate, as well as the facilitating effects of globalization and worldwide HRH shortages. The possible outcomes are discussed, particularly the externalities that relate to source and recipient countries. The actual impact of worker shortages on the delivery of health care is further clarified. Policy options for modulating HRH flows and enhancing HRH stocks are thereafter drawn. Individual as well as country interests are taken into consideration in deriving a range of applicable policy instruments. Managed migration schemes for HRH flows appear to provide the greatest flexibility for most concerned parties. The application of the derived policy framework in a leading HRH "donor" country, the Philippines, is presented.