Early COVID-19 pandemic data showed a spike in both food insecurity and poor mental health. The purpose of this study was to examine the relationship between food insecurity and mental health outcomes nine months after the start of the COVID-19 pandemic. A national survey of adults 18 years and older was administered in December 2020 (N=8,355). Multivariable logistic models and post-estimation margins commands were used to show the predicted probability of mental health outcomes (psychological distress, anxiety, and depression) by food security status. The majority of participants (68.5%) reported high/marginal food security, 15.5% had low food security, and 16.0% had very low food security. There was a strong dose response relationship between food insecurity and higher psychological distress, anxiety and depression. Fewer than one in five adults with high/marginal food security screened positive for all three mental health outcomes, while more than two in five adults with low food security screened positive for psychological distress (39.9%), depression (41.7%) and anxiety (41.3%). Among adults with very low food security, nearly half screened positive for psychological distress (47.7%), depression (48.1%) and anxiety (49.4%). Younger adults had higher prevalence of psychological distress compared to older adults regardless of food security status. Food insecure adults, particularly young adults, have higher rates of psychological distress, anxiety, and depression than their food secure counterparts. Facilitating opportunities to connect at risk populations with food assistance and affordable mental healthcare should be prioritized as the pandemic continues and beyond.