Health care workers have always been at risk for contracting tuberculosis (TB) from patients with active disease. In addition, health care workers who have active TB pose a risk for transmitting TB to patients. As a result, institutions that employ health care professionals must adopt programs to reduce the probability of transmission of TB to their employees or their patients. This article discusses the new guidelines for preventing TB issued by the Centers for Disease Control and Prevention and suggests approaches for adapting the guidelines to the needs of individual institutions. It emphasizes the importance of skin testing for early detection, correct interpretation of the tests, the approaches to determining who should be tested, and the relative frequency with which employees should be tested. It presents algorithms to assist employee health and infection control personnel in screening current and prospective employees, and in responding to positive and negative test results, and the booster effect.