Social networking protects mental health during a crisis. Prior contact with social organizations, friends, and non-friend neighbors may be associated with better trajectories of loneliness, depression and subjective memory during COVID-19. Regression analysis was conducted using longitudinal data from a representative sample of n = 3105 US adults aged ≥55 in April–October 2020. Latent profile analysis was also conducted. Prior contact with friends (B = −0.075, p < 0.001), neighbors (B = −0.048, p = 0.007), and social organizations (B = −0.073, p < 0.001) predicted for better mental health during COVID-19. Three profiles were identified: Profile 1 had the best outcomes, with prior contact with social organizations (B = −0.052, p = 0.044) predicting decreasing loneliness. For Profile 2, prior ‘meeting’ contact with friends predicted decreasing loneliness (B = −0.075, p < 0.001) and better subjective memory (B = −0.130, p = 0.011). Conversely, prior contact with neighbors (B = −0.165, p = 0.010) predicted worsening loneliness among Profile 3. The COVID-19 pandemic has had a differential impact on the mental health trajectories of aging adults with social ties of different strengths. Stronger neighborhood networks are important to mitigate poor mental health outcomes among vulnerable older adults during a crisis. Older adults who are living alone and had relied on non-friend neighbors for social connectedness require additional community supports. Policy interventions are required to mitigate the mental health impact of future pandemics.