Aviation is one of the most severely impacted industries by COVID-19. The passenger boarding-process is not only a bottleneck but is also one of the riskiest processes for COVID-19 transmission. There is a need for a decision-support tool that can proactively test the impact of COVID-19 policies on the passenger boarding-process. We achieve this by developing an adaptable modeling approach to Discrete Event Simulation (DES) that simulates the process of boarding under different COVID-19 policies and boarding-strategies. DES model was created using time and motion studies, flightlogs and manuals. Programing-logic was created using n=29 subject-matter experts. As a demonstrator-case, we tested seven of the most common boarding-strategies under different COVID-19 stages: pre-COVID, COVID-19 stage 1 and 2. Preliminary-results show the COVID-19 transmission risk may be decreased with a trade-off: passenger-satisfaction may decrease due to an increase in boarding-time and waiting-time. Steffen’s method was most-effective in minimizing COVID-19 risk but is the most difficult to implement. Reverse pyramid and Window Middle Aisle, while slightly less effective than Steffen’s method, but overall, more-effective and easier to implement with minimal COVID-19 risk. For COVID-19 stage 1 and 2, boarding time increased up to 33% and 64%, respectively, in-comparison to baseline pre-pandemic conditions. Further, up to 1.5 and 6.6 seat and aisle interferences along with a jetway-seat time of up to 13 minutes were observed. The developed modeling approach serves as a direct response to ICAO’s (International Civil Aviation Organization) need for a tool to proactively test and develop policies that minimize COVID-19 risk.