Educational policy makers in many countries recognize the need to focus their policies more directly on factors affecting the quality of teachers. Common to these policies are attempts to reform teachers' pay systems and career paths to place greater value on teachers' work and give stronger incentives for professional development. Investing in effective modes of ongoing professional learning is regarded increasingly as one of the most effective means of improving student learning outcomes. This article examines two approaches to reforming the teaching profession--one from the UK, the other in the USA. In the case of the UK, the focus will be on a comprehensive government "performance management" system for the teaching profession in England and Wales, introduced in 2000. In the USA, the focus will be on "professional certification," an emerging system for giving recognition to "accomplished" teachers provided by an independent professional body, the National Board for Professional Teaching Standards (NBPTS). Both reforms aim to improve the attractiveness of teaching as a career and to provide teachers with greater rewards for evidence of professional development. These two approaches to assessing teacher performance for career progression are compared on a number of criteria, particularly their capacity to engage all teachers in effective forms of professional development and assist them to reach their full potential, the fundamental aspiration of any performance management system. Each depends on credible methods for assessing teacher performance. The UK performance system, it will be argued, looks backwards and has little chance of achieving its aim; the US NBPTS, on the other hand, points to a possible future and has the potential to radically change the way educators think about professional development and methods for assessing teacher performance. It recognizes the power of professional forms of recognition and demonstrates the commitment teachers are prepared to give to the task of developing their own standards and methods for assessing performance. (Contains 8 footnotes.)