Called me and left a voicemail claiming to be a member of the Department of Defense and said "sorry we missed you at our appointed time," of which I had no phone appointments scheduled with the DOD, and proceeded to inform me I could call back at the number 888-986-8791. Upon looking this number up, no records popped up relating to the DOD.
The number belongs to a contracted company who performs surveys on behalf of the DoD integrated disability evaluation system. In other words if you were in the military going through a MedBoard, they want to ask you about your experience through the process. If you have complaints or want to bring something up, it would be helpful to answer the survey. It is performed with a person not an automated system. Survey takes about 15 min.