Active and reserve component members in all military branches and the Coast Guard are being invited to participate.
"The survey is unprecedented in its scale and will influence policies that affect everyone in the services," defense officials said.
The survey is voluntary and confidential. No one at the Defense Department will ever see how an individual service member responds, officials stressed.
"No service member may be ordered or pressured to complete the survey or not to complete it," officials said.
Survey respondents can forward the survey to their personal email addresses and they can complete the survey on smart phones. Service members can use duty time to complete the survey.
Service members will not all see the same survey questions.
The study will help commanders at all levels evaluate current military workplace relations, professionalism and personal safety, officials said. It will have important implications for how the military operates.
It can have implications on military training, justice and services.
The survey is being conducted independently of the Department of Defense by experts at the nonprofit, nonpartisan RAND Corporation. A full and public report of the RAND findings will be available in May 2015.