The demand for transplantable organs has outpaced the supply. Thus, 20 Americans die every day while waiting for an organ. Although most adults support organ donation, 42% are not registered. The rate is even lower among young adults who are not enrolled in/never graduated from college. The aim of this study was to use the Integrated Behavior Model (IBM) to identify factors that predicted organ donation registration among a racially diverse sample of non-student young adults. The study was observational and cross-sectional. Proportional allocation was used to identify a racially diverse sample of 550 non-student, young adults from ten states in the U.S. with the lowest registration rates. A valid and reliable survey was designed, pilot-tested, and administered. A total of 407 young adults completed the survey (74%). Only 19% were registered donors. Caucasians were more likely to be registered donors than racial minorities, χ² (3, N = 407) = 15.19, p = 0.002. Those with more positive direct attitudes toward registration were 1.5 times more likely to be registered than those who had negative direct attitudes. Among non-registrants, indirect descriptive norm and direct attitude were statistically significant predictors of behavioral intention. Moreover, those who knew someone who donated an organ and knew someone who needed a transplant were nearly three times more likely to intend to register in the next year. The IBM proved useful in elucidating factors that predicted intention to register among non-student young adults. The IBM should be used by those who desire to increase registration rates.