The National Guard (NG) was an important component of the U.S. emergency response for the coronavirus (COVID-19) pandemic. Understanding how the personal COVID-19 experiences of NG members may be associated with posttraumatic stress symptoms (PTSS) and disorder (PTSD) can inform approaches to identifying and sustaining service members' mental health. We surveyed 3,993 NG service members (75% Army; 79% enlisted; 33% 30-39 years old; 81% male) during the pandemic. Forty-six percent of participants were activated in response to COVID-19. Surveys were administered between August and December 2020. We defined personal COVID-19 experiences as having COVID-19, a family member(s) having COVID-19, and/or having a close relationship with someone who died from COVID-19. In addition, using a 4-item form of the PTSD Checklist for DSM-5 (PCL-5), current posttraumatic stress symptoms (PTSS) and probable PTSD were assessed. Linear and logistic regression analyses were conducted to examine the relationship of COVID-19 experiences to PTSS and probable PTSD, respectively. Approximately 32% of participants reported at least one personal COVID-19 experience. Univariable linear regression analyses indicated that NG service members who had a personal COVID-19 experience reported more PTSS than those with no personal experience (B = 0.53, SE = 0.12, P < .001). After adjusting for demographics and service-related characteristics, having a personal COVID-19 experience continued to be associated with higher PTSS (B = 0.48, SE = 0.12, P < .001). When examining the relationships of distinct types of personal COVID-19 experiences to PTSS and PTSD together in multivariable models, those who had a close relationship with someone who died from COVID-19 had higher levels of PTSS (B = 1.31, SE = 0.22, P < .001) and were almost 3 times more likely to have PTSD (OR = 2.94[95%CI = 1.93-4.47], P < .001). Personal COVID-19 experiences are associated with increased PTSS and PTSD risk in NG service members. Such knowledge may aid in selection of service members for activation and identifying those in need of care.