In a national survey of medical directors at 231 U.S. private health care plans that cover over two thirds of the privately insured population, we studied whether medical directors are aware when a new technology, such as laser therapy, is being used in procedures for which claims are submitted, the factors alerting them to such use, and the factors prompting them to make a specific coverage decision for the technology. We also examined possible associations between health plans' characteristics (HMO versus indemnity, size, profit status, and time in operation) and their medical directors' awareness of the use of technologies, factors alerting medical directors to their use, and factors prompting specific coverage decisions. The majority of plans were generally not aware that laser technology was being used when it was billed under a general billing code, raising the possibility that less effective or less safe technologies could be introduced rapidly into the treatment of insured populations. Nonprofit and older plans were less likely to be aware that lasers were used in some procedures than for-profit and younger plans.