What is a basic AD&D plan?

Accidental Death & Dismemberment (AD&D) insurance coverage adds low-cost accidental death protection by paying benefits in the event your death is due to accidental causes. Full or partial AD&D benefits are also payable to you following certain serious accidental injuries.

https://choices.mus.edu/basiclife_employee.html#:~:text=Accidental%20Death%20%26%20Dismemberment%20(AD%26D),following%20certain%20serious%20accidental%20injuries.