Alcohol use causes approximately 10% of deaths among adults ages 20-65 in the United States. Although previous research has demonstrated differential age-related risk relationships, it is difficult to estimate the magnitude of selection bias attributable to premature mortality based on existing cohort studies, the average age of which is greater than 50 years. The objective of our study was to assess the distribution of mortality-related harms and benefits from alcohol among adults ages 20 and older in comparison with the distribution among those older than age 50. Method: Data from the Centers for Disease Control and Prevention's Alcohol-Related Disease Impact software application from 2006-10 were used to determine the distribution of alcohol-attributable deaths (AADs) and the years of potential life lost (YPLLs) that was caused or prevented by alcohol for 54 conditions by 15-year age groupings (20-34, 35-49, 50-64, 65+) in the United States. We also determined the proportion of net deaths and YPLLs occurring in each age group, overall and by cause of death. Results: Adults ages 20-49 years experienced 35.8% of the deaths and 58.4% of the YPLLs caused by alcohol, whereas the same group accrued only 4.5% of AADs and 14.2% of YPLLs gained. Overall, 46.3% of the total net deaths and 64.7% of the net YPLLs occurred among those ages 20-49; adding net deaths occurring among those ages 20-49 to those occurring after age 50 results in an 86.3% relative increase in net deaths. Conclusions: Because of premature mortality, alcohol-mortality associations based on cohort studies may underestimate negative health consequences compared with those among the general population. (J. Stud. Alcohol Drugs,