Background: Suicide remains a major public health problem in the United States. The purpose of this study was to examine trends in suicide ideation, planning, and attempts among a national sample of US adults. Method: We used aggregated 2015–2018 data from the National Survey Drug Use and Health Survey. We utilized demographic and substance use questions with each suicide behavior. We assessed weighted absolute and relative changes in a national sample of 7,654 adults. Results: Results revealed that from 2015 to 2018, there was a 16.0% increase in suicide ideation, 18.6% increase in suicide planning, and 11.6% increase in suicide attempts. Significant increases in each behavior were found in African Americans, younger adults, sexual minorities, and individuals who reported past-year drug use. Limitations: Limitations include self-report of suicidal behaviors and desirability of answers. Conclusion: We believe our findings can inform harm reduction efforts and health messages surrounding suicide prevention.