The word "non-performers" refers to individuals who are not up to the mark in terms of achieving certain standards or goals. The antonyms for non-performers include high achievers, performers, achievers, winners, top performers, successful individuals, star performers and so on. These are people who are successful in their respective fields and are consistently able to meet or exceed expectations. They possess a strong work ethic, determination, and focus, and strive for excellence in everything they do. As opposed to non-performers who may struggle to accomplish tasks, high achievers are able to tackle challenges head-on, display a positive attitude and ultimately achieve success in their chosen endeavors.