The range of application of artificial intelligence (AI) is vast, as is the potential for harm. Growing awareness of potential risks from AI systems has spurred action to address those risks while eroding confidence in AI systems and the organizations that develop them. A 2019 study (1) found more than 80 organizations that have published and adopted “AI ethics principles,” and more have joined since. But the principles often leave a gap between the “what” and the “how” of trustworthy AI development. Such gaps have enabled questionable or ethically dubious behavior, which casts doubts on the trustworthiness of specific organizations, and the field more broadly. There is thus an urgent need for concrete methods that both enable AI developers to prevent harm and allow them to demonstrate their trustworthiness through verifiable behavior. Below, we explore mechanisms [drawn from (2)] for creating an ecosystem where AI developers can earn trust—if they are trustworthy (see the figure). Better assessment of developer trustworthiness could inform user choice, employee actions, investment decisions, legal recourse, and emerging governance regimes.