The United States' education system needs to take its critical next step: fairly and accurately measuring teacher performance. Successful reforms to teacher pay, career advancement, professional development, retention, and other human capital systems that lead to better student outcomes depend on it. Where can the U.S. find the best-practice know-how for this? To start, it should look to nations that have revamped teacher performance measurement to sustain teaching excellence, and Singapore offers a remarkable example. In the early 2000s, the small but racially and economically diverse nation of Singapore designed and implemented a new, performance-linked method of measuring teacher effectiveness that enables measurement of teachers in all subjects and grades. Singapore had already developed a high-performing education system. But as global economic opportunities for its citizens increased, it needed to ensure continued recruitment, retention, and performance of talented teachers. Today, Singapore's students consistently perform at the top of internationally comparable exams, and 98 percent of Singapore's sixth-grade students achieve math standards more rigorous than the eighth-grade standards on the U.S. NAEP exam (National Assessment of Educational Progress). What can the United States learn from Singapore? Much, it seems, and Singapore knows it. The complete recipe for its educational success is not public, and determining the ingredients in the secret sauce is a challenge. But one element stands out: the development and thorough use of performance-linked "competencies" to measure, reward, and develop teacher performance. This paper presents a brief background on the state of teacher evaluation in the United States, the case for why the country can learn much from Singapore, and key facts about Singapore's competency-based teacher evaluation system. (Contains 6 figures, 2 tables, and 65 notes.)